hot water heater safety valve quotation

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There are many uses of valves - mainly controlling the flow of fluids and pressure. Some examples include regulating water for irrigation, industrial uses for controlling processes, and residential piping systems. Magnetic valves like those using the solenoid, are often used in a range of industrial processes. Whereas backflow preventers are often used in residential and commercial buildings to ensure the safety and hygiene of the water supplies. Whether you are designing a regulation system for irrigation or merely looking for a new replacement, you will be able to find whatever type of safety valve for electric water heater that you need. Our products vary from check valves to pressure reducing valves, ball valves, butterfly valves, thermostatic mixing valves, and a lot more.

Temperature and pressure relief valves are used in residential and commercial water heater and hot water storage tank applications to provide automatic temperature and pressure protection to hot water supply tanks and hot water heaters. We have a full-line of products in multiple sizes, pressure ratings, and inlet/outlet types.

The importance of installing the correct temperature and pressure relief valve on a water heater or hot-water storage tank cannot be overemphasized. This applies to new vessels as well as relief valve replacements. The importance of installing a valve with the correct pressure rating is common knowledge to many, but it also is crucial to install a valve with the appropriate relieving capacity rating. Many times the capacity factor is overlooked.

The code of construction of the vessel itself can play a key role in choosing the correct valve capacity. Unfortunately, the code of construction criteria is unknown to many and overlooked by others.

As the name indicates, T&P relief valves are designed to protect water heaters and hot-water storage vessels against excess temperature and excess pressure. Most valves are rated at 150 psi and 210° F, but their capacity ratings vary greatly. Sometimes, an additional T&P relief valve with a lower temperature and pressure rating (typically 180° and 100 psi) is installed in a plastic hot-water distribution system to protect the piping system itself. A T&P relief valve is, in essence, a dual device because it meets the code requirements of an individual temperature relief valve and an individual pressure relief valve.

The temperature function of the valve is controlled by an internal thermostatic element. At 210°, the internal expansion within the probe causes a piston to push against the valve’s disk. The spring is overpowered and compressed, and the water escapes between the disc and seat. The extremely hot water within the tank is forced out under pressure as cold water replenishes the discharge. The cold water rushing into the vessel lowers the water temperature, and when the temperature drops back below 210°, the valve is reseated.

The pressure function of the valve also is controlled by the spring, disc and seat. When the pressure exceeds the valve’s pressure rating, the water pressure overcomes the spring. The spring is compressed (just like a typical pressure-only relief valve) and the water escapes between the disc and seat.

It is important to note that when the valve is weeping or dripping, the cause is usually excessive pressure. Many times this is caused by thermal expansion. A T&P relief valve is not designed to nor should it be used to continuously control thermal expansion within a closed system. Thermal expansion of hot water within a closed system should be controlled with the installation of an approved expansion tank or by other means permitted by local code.

Dripping may continue because of debris within the valve, such as a build-up of calcium in the seat, and over time, large mineral deposits can make the valve ineffective. When a valve is discharging a large quantity of water, the cause is almost always excessive temperature.

The only way to determine the maximum allowable working pressure of a vessel is to read the nameplate that is attached to it. The pressure on the valve’s tag must be compared to the pressure on the vessel’s nameplate. The pressure rating of the relief valve must be equal to or less than the MAWP of the vessel. Most water heaters have an MAWP of 150 psi; however, some are rated higher, typically 160 psi. Some storage vessels have a lower pressure rating; they are commonly rated 125 psi.

Another factor in determining the pressure rating of the T&P relief valve is the code itself. Model codes require the T&P relief valve be set no higher than 150 psi. Therefore, a water heater with a MAWP of 160 psi still requires a T&P relief valve set at 150 psi, even though the vessel is designed and built to withstand a higher pressure.

The relieving capacity of the valve must be equal to or greater than the Btu/hr. of the vessel. The thermal capacity of the water heater can be found on its nameplate along with the MAWP. The confusion in choosing the correct T&P relief valve resides on the relief valve’s nametag itself. T&P relief valves display two relieving capacity ratings. One is the American Society of Mechanical Engineers/National Board of Boiler and Pressure Vessel Inspectors rating, and the other is the Canadian Standards Association/American National Standards Institute Z21.22 rating.

The relieving capacity of the valve’s ASME/NB rating is established by Section IV, Part HG of the “ASME Boiler and Pressure Vessel Code.” The code reads, “Capacity certification tests of safety relief valves for water heating and hot-water supply boilers shall be conducted at 110% of the pressure for which the valve is set to operate.” So the capacity of a T&P relief valve set at 150 psi is based on its vessel pressurized to 165 psi.

The ASME/NB relieving capacity rating is more lenient than the CSA rating. The CSA rating is based on 15 psi of steam pressure, so the CSA rating will always be lower and, therefore, more stringent than the ASME/NB rating. ASME HLW water heaters are built to a more stringent code of construction than ANSI Z21 water heaters. The use of a valve’s ASME/NB capacity rating to protect an ANSI-built vessel could present a potentially dangerous condition.

Chapter 5, Section 504.4 of the 2012 International Plumbing Code specifically requires relief valves to conform to the Z21.22 standard; the code is very concise. Some of the other model codes are not as clear as the IPC. Section 504 of the Uniform Plumbing Code only references an approved, listed device installed in accordance with the listing and the manufacturer’s installation instructions; however, the Z21.22 standard is included in Table 1401.1.

A leak from your water heater’s pressure relief valve is a major concern, especially if it’s the first time dealing with this problem. While some people tend to panic and get help immediately, others may just shrug their shoulders and assume that the leak is a common occurrence. However, there are many causes of leaks in water pressure relief valves. And all these must be addressed immediately given the high risks of property damage and hazards that can occur if the issue is ignored.

The pressure relief valve gives steam and water a chance to escape when either the pressure or temperature in the water tank gets too high. A malfunctioning valve can cause the water heater to explode and is the major cause of water heater explosions. In water heater pressure relief valves, the valve is set to open when the pressure exceeds 150 psi.

A leaking valve is not always a broken valve. In some cases, a water heater’s pressure relief valve may leak because it is functioning as intended. As excess pressure is relieved out of your water heater system, some water may leak. This necessitates the need to test the pressure in your water heater.

The process is not complicated. However, if you are not comfortable checking the water pressure, you can always contact your technician. To test the pressure, use a pressure gauge and attach it to either the cold-water pipe or the hot water pipe. However, one of the easiest places to connect the pressure gauge is the outdoor hose faucets. For this, ensure you purchase a pressure gauge that is designed for garden hoses.

Turn off all water outlets and faucets. The pressure reading should be between 40 psi- 80 psi. If the gauge shows a psi reading of 150 and above, then the cause of the leak could be high pressure. If the water pressure is normal and the leak is persistent, then high water pressure is not the cause of the leak.

If you get a high-pressure reading, then you could be dealing with a closed plumbing system issue. This means that when the water is heated, the pressure increases as it should. But with nowhere to go, the valves open to relieve the pressure. Luckily, this can be solved by installing an expansion tank that gives the pressure an outlet other than a pressure relief valve.

Although rare, your water heater’s pressure relief valve could be leaking as a result of excessively high temperatures. However, the water has to be near the boiling point. To check the water temperature, ensure you turn on the hot water faucet. Run the water for one minute and use a meat thermometer to take the temperature reading. The temperature should be around 120 degrees. If more than this, then you need to have the water heater checked. The water temperature would need to be close to 212 degrees to set off the relief valve.

While this is an uncommon occurrence, it is not far-fetched. Your technician could have used a pressure valve for another appliance since they have the same function. However, these other pressure relief valves are set to go off at a lower psi. For instance, boiler pressure valves go off at 30 psi. If installed in a water heater, you are likely to get leaks immediately after installation. As such, if you have had your water heater for years and only experienced the leaks after a long period, then this is an unlikely cause of the leak.

A slight leak may occur if your water heater’s pressure relief valve has not been opened for a while, say a few years. While this leak is normal and may not be an indicator of a problem with the water heater system, you may need to replace the valve if the leak becomes more serious. It is cheaper to replace the entire valve than to repair it and have to deal with the same problem later on.

A leak in your water heater’s pressure relief valve could also be caused by a faulty pressure relief valve. While pressure relief valves barely break down, excessive wear and improper installation can cause extensive damage. Unfortunately, a faulty pressure valve can not be repaired and must be replaced. However, the cost of pressure valves is affordable and ranges around $30.

Know your water heater and how it functions– Water heaters can be intimidating, especially for people with less technical know-how.  Understand what every part of the system plays in heating water such as the water shutoff valve, drain valve, thermostat, and pressure relief valve. This eases the maintenance routine and ensures you have a fair understanding of any malfunctions.

Insulate the pipes and the water heater– By insulating both the cold water and hot water pipes, you get to prevent condensation while also reducing heat loss. Also, insulating the water heater helps to keep water hot when surrounded by cold air.

Carry out regular maintenance– Inspect your water heater monthly, ensuring that all valves and pipes are in good shape. This also helps you catch corrosion and leaks early enough before they turn out to be bigger problems. And every year, carry out a water heater flush. Given that you cannot pinpoint all problems, have a qualified technician inspect the system annually.

Regardless of the possible cause of a leak in your water heater’s pressure relief valve, please contact a qualified plumber as soon as possible. And if you think it’s a problem that you can solve without getting help, ensure you have a qualified plumber confirm that the system is performing optimally after. Water heater issues should not be taken lightly as they can cause more issues, even explosions.

WAGS™prevents disastrous floods and untold damage to your property, and avoids costly insurance claims. The WAGS™ valve is designed to shut off the water supply (plus gas supply for gas-fired heaters) in the event of a water leak from a water heater.

The WAGS™ valve sits in a drip pan under the water heater and is activated when leaking water accumulates to a predetermined level in the pan. Once activated, the industrial-duty, spring loaded piston in the valve shuts off the water flow, and the gas supply - if so equipped.

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The temperature and pressure relief valve (sometimes called a tpr valve or tp valve) helps regulate the pressure and temperature of the water inside the tank. Both can be extremely dangerous if too high.

The Temperature and pressure relief valve on all water heaters automatically opens when they sense an excessive amount of pressure or heat in the water heater tank, alleviating any damage they might have caused. Water will leak through the valve and discharge tube after all excess air escapes from the tank.

Another function of the temperature and pressure relief valve is to release water from the tank if it gets too hot.Thermostats and temperature controlscan go out in time. When the water in our hot water tank gets to a dangerous level, we rely on the pressure relief valve to expel it from the tank and through the discharge tube before it can give us 3rd-degree burns.

If you have questions about whether your temperature and pressure relief valve is leaking or if other problems are causing it to release water, call Hackler Plumbing today. Our professionals will be able to give you the answers you need after a thorough investigation of your water heater temperature and pressure relief valve.

The best way to prevent a faulty temperature and pressure relief valve is to maintain it regularly. The pressure relief valve must work right as it is the most crucial safety feature on the water heater.

Preventive maintenance is the best way to care for a water heater. These are the best two ways to check and maintain your temperature and pressure relief valve.

Check for water leaking from the valve or attached pipe. A water leak is often a sign something is wrong with the pressure relief valve. A damaged rubber gasket or faulty lifting handle can allow water to seep through the valve. Call Hackler Plumbing today if your temperature and pressure relief valve is damaged.

Test the valve annually by lifting the handle and relieving pressure from the water heater tank. Every water heater needs flushing annually as well. We shouldn’t have any surprises with a faulty temperature and pressure relief valve as long as we regularly maintain our water heater correctly.

The temperature and pressure relief valve is a safety feature we need to work on any water heater. Many components work together on a water heater so that our water is at the perfect temperature and comes out with just the right amount of pressure.

The temperature and pressure release valve protect us when any components on the water heater go out. It’s important to remember that a pressure valve is made to discharge water from the tank if there are any issues. Figuring out if it’s leaking or not can be confusing.

Let’s say we change the temperature and pressure valve and it continues to leak after replacement. Now we know there is a more serious problem with our water heater and we wasted all that time and money.

There is a lot more to a water heater than meets the eye. One of the most common issues inside a water heater tank is thermal expansion. The professionals at Hackler Plumbing can tell if thermal expansion is occurring in your system and what you can do to solve the problem.

Water expands when it gets heated. Our water heater tank and plumbing lines are a “closed” system if a check valve or pressure regulator is on the water supply for the house.

When the water expands in any closed system, it will have nowhere to go. When the temperature builds up in the tank, so does the pressure. The temperature and pressure relief valve work to alleviate this excess build-up to keep our water heater from exploding. In some cases, serious measures will need to be taken to handle the extra pressure caused by thermal expansion in a closed system.

Adding an expansion tank to a closed system can completely stop a leaking T&P valve. If you’ve replaced your temperature and pressure relief valve, but it’s still leaking, one of our professionals at Hackler Plumbing will be happy to inspect your plumbing system.

They can determine whether or not you have a check valve or pressure regulator installed and help solve your temperature and pressure relief valve problem. They will even be able to install an expansion tank if they discover you do have a closed system.

It doesn’t matter where the expansion tank is installed, as long as the water has somewhere to go when the thermal expansion occurs. Call Hackler Plumbing today if you think you require an expansion tank installation. We are your local McKinney plumbing company serving the surrounding Metroplex area and are here to fix all water heater-related problems and can performtankless water complete installations.

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Temperature Pressure Relieve (TPR) valves are installed on water heaters as a safety device to prevent water heaters from exploding. Building codes require that a TPR valve be installed.

Water heaters are designed to be safe. If the water heater is new, the risk of explosion is low. As the water heater ages, the risk of explosion increases. The life expectancy on water heaters is 8 to 12 years.

TPR valves are cheap and the installation is not very expensive. Total cost for parts and professional installation by a licensed plumber is between $150 and $300 dollars.

Homeowners can also install TPR valves themselves for about $20. There are videos and instruction manuals to guide the homeowner in correctly installing a TPR valve.

TPR valves can be installed either on the top or the side of a water heater. They should always have a drain line connected to the valve instead of being left open as shown below.

POST a QUESTION or COMMENT about heating boiler or water heater (water cylinder) pressure/temperature relief valves or TP valves on all types of water heating appliances

This article series explains the requirement for temperature and pressure relief valves on water heaters, calorifers, geyers, or hot water cylinders, and we give relief valve installation, inspection, diagnosis and repair procedures for these important safety devices.

You can easily verify the TPR valve on your 40 gallon water heater by looking at the information on the relief valve data tag and comparing that with the INPUT BTUH rating of your water heater.

Great info here, but I have an ongoing problem. On a fairly new electric hot water heater tank (2 years) I replaced the relief valve because it was leaking and occasionally discharging. However the new relief valve did not correct the problem, still leaks constantly. So, I replaced both thermostats thinking one or the other was not shutting off the heating elements and it was over heating and discharging. Still, it drips out the relief line.

If your incoming water pressure is a bit high, or if there is a water hammer oroblem you may need an expansion tank, else the valve may need replacement.

Water heater overflow pipe constantly dripping so I tested the TRV and water gushed out of pipe like I turned on a faucet. So I let go of it. I know that is not normal.

The pipe is hot so I checked my heat settings and turned it to 120 degrees ) it was a little above that ) It is still constantly dripping (trickle not drip drop). Suggestions?

I have problem of my apartment have 2 Ariston 40ltr water heater.but I got problem my only one water heater pressure relief valve water dripping.my plumber change 2times of pressure relief valve but still same problem when I on my water heater it"s dropping after few minutes. How I solve this problem?

On some water heaters the shorter stem is needed because given the TPR valve mounting position, such as a side-mount TPR valve, the long stem might touch an internal part of the heater such as a center flue or a dip tube.

When the water heater (or in other countries cylinder or calorifer or geyser) is cold the pressure inside it should be the same as incoming building water pressure - in your case 70 psi.

If the expanding water were in an "open" system that expansion would just push back into the cold water pipes and pressure wouldn"t increase. But where there are check valves or other obstructions in the piping system, pressure can build rapidly as water is heated.

A domestic water heater is typically designed for up to 150 psi working pressure. At higher pressures we expect the temperature/pressure relief valve to open to relieve pressure.

But in some homes the water heater pressure just from thermal expansion causes dripping at the TPR valve (an unsafe condition); in that case, if all else is normal, yes it makes sense to add a thermal expansion tank to the water heating system.

If my residential pressure is 70 psi which of the pressure inside my hot water heater tank be? It’s fluctuating from 140 psi to as low as 45. I think the expansion tank is my next replacement of course. But what should the pressure in the tank normally be in relation to the system pressure?

I"m just your text I really don"t have an intelligent guess about why the pressure or temperature relief valve is discharging but it"s definitely a safety concern.

How do I make the heater itself be unsafe now, but even if the problem we"re simply a leaky valve itself that leak can lead to clogging which in turn can cause the valve to fail to open in an emergency. The result of that would be a dangerous explosion of a water heater

I just happen to notice water coming out of a pvc pipe that is located coming out of the house. Our hot water heater is located on the 2nd floor and have come to the conclusion that the TPR valve engaged itself. I understand that this works because either the temp. or the press. became too much and this is the safety feature at work.

My question is, why now? We haven"t increased the temp. of the water, and its not what I would consider cold outside, let alone, this is upstairs in a climate controlled area. Is this an indication that something is wrong, or is it possible the last time I increased the temp. on the water heater, it has been discharging all this time and I just never was outside when it did it?

Watch out: What you describe is improper water heater operation and is extremely dangerous, risking a catastrophic BLEVE EXPLOSION. inspectapedia.com/plumbing/BLEVE-Explosions.php

When a water heater is overheating the increase in pressure or temperature or both cause spillage of water at the temperature and pressure relief valve. The purpose of the relief valve, also called TPR valve (temperature, pressure relief) is specifically to prevent over-pressure from bursting or exploding the water heater tank. Working properly, then, the TPR valve is a critical safety device.

When that condition (overheating, TPR spilling) is permitted to continue for some time, deposits of minerals, silt, debris from the hot water moving through the TPR valve mouth, can ultimately clog the relief valve.

If a relief valve clogs it can fail to open in response to over-temperature or over-pressure. The result can be an exploding water tank with great force and damage and risk of injury or worse.

If the heater has not been properly repaired already, it should be turned OFF IMMEDIATELY and you should have the heater or its controls repaired by a qualfied plumber.

We have a huge water bill. We had plumber our who found no leaks with the water heater but did find it was massively over heating which meant the tempature gage was broken.

On most water heaters the tapping for hot, cold, dip tube and relief valve are marked by a label or a stamping into the steel. If you don"t see that we need to start with the manual which means you need the brand and model

Watch out: do not install a T&P valve at a more-remote spot like downstream on the hot water piping, and do not modify the relief valve in any way - doing so is unsafe.

I had my hot water heater pressure relief due to a constant discharge of water. The plumber said the seat had worn over time allowing water to bypass. A few days later...leaking again.

Checked the pressure on the water line closest to the meter and got a reading of 80 psi. Installed a pressure regulator set it at 60 and one day later relief still has a intermittent discharge, the water thermostat on the heater is set to normal and I pulled some hot water directly form the heater and it tested at 120 degrees.

It is the case however that when someone messes with a TP valve it can open and then fail to shut - e.g. if debris then enters the valve seat or if its gasket blows out at that time.

You may need a hot water heater expansion tank. If the incoming water pressure is within normal ranges (80 is a bit high - about 10 psi over what I"d recommend but alone not likely to explain the issue you are having), and if the water heater temperatures are within normal range (where you tested is of course at a lower point than in the heater at the temperature sensor but 120 is well below the opening temp of around boiling) then the problem is elsewhere.

I tried to open the pressure relief valve on my water heater and It won"t open by my hand and I don"t want to use a wrench or pliers to force it. How should I get it open. It has been 7 or 8 years since it was installed.

Watch out: IF the test lever is stuck this is an important discovery, as it quite possibly means that the valve opening mechanism is stuck as well - that would be very dangerous - should an overpressure occur and the valve fail to open as it should the water heater becomes a rocket or a bomb.

My water heater is making a loud (very loud) whistling noise- my water heater normally makes loud banging noises and loud gurgles and popping sounds- I called maint- they said it is "normal"

- the water heater is 12 yrs old and as he puts it "everyone"s does that" - but the last time it whistled- we ended up having no hot water and they had to replace the element.

Will the gas leak and will the water leak out of the tank in the next 24 hours? I have kids and animals in the room with the water heater. It should be outside like most apts- but they have it in the bedroom and it"s not safe.

PS- now there is NO noise coming from the water heater- and there is always some type of noise - so now it really makes me nervous and it"s 12 am. I"m afraid to take a shower in the morning for fear of the water tank blowing up.

With a hot water system located inside a cupboard what do you do with the "drip drip drip" coming with pressure relief? Is it simply dropping onto carpet?

Watch out: FIRST you are describing an UNSAFE CONDITION - a dripping relief valve ultimately clogs and stops dripping - at which point it also is no longer protecting the building from an exploding water heater.

So the cause of the trouble needs to be diagnosed: a leaky TP valve, overpressure in the system, overheating at the water heater, or water hammer or some other cause.

Do NOT simply route the dripping valve to a disposal location that is no longer visible or in the future the dangerous condition might remain undetected. (search InspectApedia.com for TUNDISH to read about a solution).

What is the minimum clearance distance that is required from the bottom of the countertop to allow the temperature relief valve adequate clearance? Is there a code spec for this?

Julie a look at installation details for TP valves on water heaters didn"t come up with an over-head clearance, though some common sense would indicate you"d need enough space for the test lever to be operated AND enough space to remove and replace the valve when needed.

Since a top-mounted TP valve has a temperature sensing stem that protrudes downwards into the water heater the removal space will be more than you think

On a small water heater (cylinder) the extension of the sensor is about 3" while on larger water heater cylinders that added length could be as mmuch as 9" below the inlet. Adding that 9" of sensor to the TP valve body and lever height (anywhere from 5 5/8" to 9 1/4") means the minimum (for the smallest valve size) valve total length is about 9" and the larger valve could be much larger.

Now we can slightly tip a valve to get it out of the heater, buyt - I"d like to see 12" or more to give both working space and space to remove the valve.

My electric water heater experiencing too much water discharge into the discharge tube. I called in a plumber and he adjusted the control with his tools which stopped this bypass problem for a few weeks. I am not sure if this is due to problem with the p-trap valve or tube.

In general the pressure/temperature relief valve on any water heater will open at a pressure low enough to protect the tank from a BLEVE explosion (discussed above) AND/OR at an abnormally high temperature (e.g. over 210F) but the TP valve also must be sized to be capable of dumping hot water and/or steam fast enough to exceed the BTU input rate of the heating appliance.

There should be a tapping on the upper side of the heater intended to accept a pressure/temperature relief valve. Be sure to install a valve with the proper capacity matched to the unit"s input BTUH.

I"d ask for help from a plumber to find the tapping and install a TP valve. You may need to remove insulation to expose the tapping and plug in that threaded opening.

We came home to a t&P valve violently discharging, called Rheem they advised to buy new valve and replace--gave us no instructions-- We just slapped a new one on turned the cold water back on and then immediately followed turning back on the hot water heater the new valve discharged a gushing stream.

Called Rheem again and they said oh no there are steps that must be followed, so we drained the hot water heater and started "Fresh" and followed the steps to a "T".

But make a check of the system water pressure to see its level is abnormally high - if water pressure is above the TP valve pressure (or if you bought the wrong type of TP valve) that could be the trouble.

The system you describe is unsafe and should be turned off. We can"t know if the problem is a leaky T&P valve or a problem with the water heater and overheating.

No that"s dangerous and prohibited. Up-piped TPR discharge piping can hold water in the line causing the valve operating mechanism to clog with minerals or debris. The risk is a BLEVE EXPLOSION.

Hi My hot water system is solar on roof with a 300 lt tank the tank is dumping its full content about the same time everyday the water is coming from the copper pipe on the wall

In a photo above on this page you can see a flexible 3/4" copper tube used in the routing of the discharge of a TP valve from the top of a water heater. No one called out the use of that piping material itself as a hazard, but there can be hazards nonetheless depending on how that tube is routed - such as to a hidden location without a Tundish or routed "up" from the TP valve itself.

So ... it depends. If for example someone installed a flexible line to replace a straight downtube running down the side of a water heater from the TP valve, I"d be worried that some fool would come along and bend the tubing "up" - as nothing prevents them from doing so.

SO if I I were a building inspector given final authority I"d object to that installation. But I might not object to use of the same tubing connecting properly beween a valve"s discharge opening and a proper destination.

Discharge line must be same size as valve outlet, be pitched down for free draining, and have no shut-off valve or obstructions throughout its entire length.

2. it is not permissible to terminate a TPR valve discharge line with a threaded fitting - the reasoning is that it"s too easy for someone to screw a cap onto a dripping line, leading ultimately to a BLEVE explosion.

I am in the middle od disputing a denied claim with a Home Warranty company who is trying to tell me thet the water heater does not operate properly with the piping being pointed toward the floor.

So my question is: does the piping on the pressure relief valve effect the operation of the water heater. Is there somewhere that documents that although this may be a safety issue, the water heater still will function.

You"ll see this in the valve installation instructions dpfrom the manufacturer as well as in researched articles found here. Pointing a tp valve up is improper, risks clogging, failure, and a catastrophic BLEVE explosion.

If your insurance company says the valve should not point down you are welcome to quote me as observing that they are dead wrong and at are risking killing someone.

I have a friend who recently switched from well to city water, and now her TP relief valve is leaking. she says it starts before it reaches temperature. she has already replaced the valve. and she didn"t vent the air the first time she filled the tank.

I suspect either she needs a pressure regulator from the city water pressure, or, and I don"t know if this is possible, but its an electric water heater and because it wasn"t vented when she filled the tank an air pocket could have let the top element burn out, and it is possibly creating electrolysis offgasses causing a pressure buildup.

Interesting thoughts, Gary. I"ve not considered troubles with burning out an upper electrode when re-filling an empty water tank. It"d be easy enough to test. See

It would be no surprise if higher city water pressure was causing a water hammer problem OR an over-pressure problem that was causing the TP valve to leak.

I have a friend who recently switched from well to city water, and now her TP relief valve is leaking. she says it starts before it reaches temperature. she has already replaced the valve. and she didn"t vent the air the first time she filled the tank.

I suspect either she needs a pressure regulator from the city water pressure, or, and I don"t know if this is possible, but its an electric water heater and because it wasn"t vented when she filled the tank an air pocket could have let the top element burn out, and it is possibly creating electrolysis offgasses causing a pressure buildup.

My first thought was that incoming city water pressure may be higher than what the well water system delivered, and that perhaps the pressure regulator on the city water supply is not properly adjusted. Start by testing the building water pressure to see what youv"e got. Higher than 70 psi is likely to cause leak trouble.

It would be no surprise if higher city water pressure was causing a water hammer problem OR an over-pressure problem that was causing the TP valve to leak.

water heater relive valve on side of water heater needs to be put on top of water heater so it flows down is it hard to change it to the top of the heater so it flows down the out side to the out side of the wall

3. IF the valve is taken out through a wall and/or to a location not readily visible by building occupants, in order to know if the valve is leaking (and thus that a dangerous condition exists) install a Tundish fitting (Search InspectApedia for "tundish" to read details).

Electric water heater in our rental, the bottom left of the rim has raised 1/4". Glue/insulation from inside is showing. I"d like to test the valve but a plumber was here in October and said it worked. Yesterday they sent a handyman when I complained of the "shift", he"s says it"s okay. What do I do?

Can a handheld shower head, with shut off valve, cause temperature release valve on water heater to open? I have a leaking temperature release valve and I think it"s due to when we shut off the shower head, to save water, the pressure in the lines is getting pushed to the water heater and the release valve is opening. Is this possible, and if so, how to fix? We would like to continue to use the shower head. Install a expansion tank?

In my OPINION, probably not. Though water hammer (that can be caused by some plumbing controls, valves, faucets) can cause the TPR valve to open, leak, or drip. And a combination of water hammer and high building water pressure increases that leak risk.

My wife and I have never heard the water hammer noise when we"ve closed the shower head. We hear a hissing sound, thought it was pressure having a way to escape. We"ve recently bought this house and the water heater is approximately 5 years old.

The TPR valve looks like it was replaced at the same time, being with the research that I"ve already done, the TPR valve should be replaced with the new water heater.

Both thermostats are set at 125 degrees. In your opinion, what could be causing the TPR valve to open? Could the valve already be worn out, faulty, or should I have someone come and look at it and see if its just the layout of my plumbing?

Where are you hearing the hissing. If it is right at the water heater that may be normal; Particularly some electric water heaters will hiss as the element is heating up incoming cold water, or scale in the heater may cause hissing as well as rumbling or other noises in the heater as it heats water.

There should be no discharge from the TP relief valve. If there is a discharge of water (or rarely, air) then either the valve is bad or the system is at an unsafe temperature or pressure.

Compare the rating of your TPR valve to the set temp of your heater; you could perhaps also measure water pressure there, attaching a portable pressure gauge to the heater drain valve. ( inspectapedia.com/water/Water_Pressure_Measure.php )

... thanks for your input. To elaborate on the hissing sound; that sound comes out of our shower head while the shower is running (showering). We control the water pressure coming out of our shower head by the shower shut off valve.

Thought: When we moved into this house we, my Wife and I, went to use the sink in the kitchen and I had to turn the cold shut off valve down a little, not all the way, to control the amount of water pressure coming out of the faucet; just like we do with our shower. With the cold water shut off valve completely open, water comes out with a lot of force.

Could this be a clue to the TPR? That the water pressure coming from the main line coming into the house is too high? Isn"t there a pressure control valve/monitor on the main line coming into the house?

If this is most probable to answer the TPR valve problem, do I need to have the pressure control valve/monitor looked at, or install an expansion tank?

Indeed shower head noise is related to pressure and flow rate through the device. Some shower heads mix air or use other flow restricting designs to reduce water usage while giving a strong spray. I"d try changing the shower head to see if the noise changes.

Start by checking the building water pressure and pressure regulator device(s). If your pressure is over about 70 psi that"s a bit high and not just noise but leaks can be an issue.

I was doing research on water pressure gauges, completely coincidental that, that was your suggestion, and during one of the videos the instructor stated that your TPR valve will leak if your water pressure is too high. So I went to Lowes bought me a water pressure gauge.

And what did I read...110 PSI. Did a functions test on my water pressure reducing valve and noted no difference. Replacement of the water reducing valve will hopefully fix the problem. Thought you would like an update. Thanks again for your help.

we discuss the thermal expansion of water - pressure increases a bit as we heat up water in a closed system. (That"s why some hot water systems include an expansion tank). "Typically the pressure/temperature relief valves on domestic water heaters are set to open at 100, 125, or 150 psi (6.9, 8.61, or 10.34 bar)."

So with a starting pressure of 110 psi, it"d be not a surprise if the water heater TPR was leaking. Take a look at the label on your TPR valve on your water heater and let me know the brand, model, and its operating pressure and temperature range.

And yeah, if you cannot successfully lower the incoming water pressure to say 70 psi, I"d replace the pressure regulator OR - at some buildings it"s necessary to install two stages of water pressure regulators to handle very high incoming pressure.

My water heater was got replaced 6 months ago. Since then whenever the hot water gets turned on, there is a intermittent band sound occurs. It only happens when hot water turns on.

Watch out: banging pipes due to water hammer can also cause the water heater"s temperature/pressure relief valve to discharge or leak. Over time that could become unsafe.

Village inspector for pending home purchase said "blow off valve on hot water heater is required to be six inxhes from the floor." But arent these valves pre-installed into the heater? How can I raise or lower it???

No, the valve, properly called a temperature/pressure relief valve, is installed in a tapping on the water heater tank, typically near or on the tank top where water is hottest.

But yes, the TPR valve must have a discharge tube that terminates close to the floor or at an approved location to reduce risk of scalding someone if the valve opens.

David, if the washer was an internal part in the TP valve, while the part might be replaceable (some valves can be disassembled) I"d just replace the whole valve. It"s a safer course. I once made an emergency midnight repair by cutting a new washer out of a piece of tupperware

- so that the house could have heat until the next day when we could pick up a replacement valve. But nobody would be willing to bet the lives of building occupants on a modified relief valve. We put in a new valve the next morning.

My tankless water heater randomly shoots out water like a hose would the TMP valve was replaced-plumber is saying pressure from the street is too high and we should install a PRV to control water pressure and resolve issue-Could there be any other issues?

If street pressure is too high the TPR valve will indeed be likely to spill water as it heats up; this is an unsafe situation for several reasons, risking at the very worst blowing up the system if the repeatedly-spilling valve becomes clogged.

Check the incoming water pressure and compare that with the pressure range your heater manufacturer says they can handle as well as comparing it with the operating pressure of the TPR valve. You may need to install a pressure regulator at the point at which water enters the home.

I have a gas water heater pressure/temperature valve that needs to be replaced. Have you ever drained the water inside the water heater through the pressure/temperature relief valve as far as possible, then remove the valve for a quick change with a new one. I expect some water to run out during the valve replacement.

The water heater has a bottom plastic drain valve, and I would rather not go there to drain the water down, knowing the calcium deposits in the bottom could get stir up causing added problems, not to mention the plugging up of that bottom drain valve, possibly getting into the hot water piping running to the sink faucets on startup.

Gary the TPR valve will only drain off the water down to the valve mounting tapping; That"s close to enough though you can expect a bit of spillage when you remove the old valve.

I think you meant water leaks out, right Mike? It may be possible to repair this leak - IF the tapping into which the relief valve is screwed is not badly corroded. You"d need to drain the tank below the level of the tapping, remove the valve, clean the treads, and using pipe dope or teflon tape, re-make the connection using a new TPR valve (to be safest).

I want to increase water pressure from my boiler to get heat to more baseboard heaters. The boiler recommends 30 lbs relief valve. Should I change it to 45 lb

My question is my new water heater has a side mounted t&p line that is located on the side of the tank and on the opposite side of where the piping stubs out of the wall for discharge. What do I do in this situation?

Watch out: never pipe a relief valve discharge tube "up" from the relief valve - doing so risks BLEVE EXPLOSIONS from a clogged valve. You"ll need to make a new side wall discharge to a location that is always visible.

I just replaced my water heater (electric) and it is was very cold in the attic about 44 degrees. Water fill was very cold as well. No leaks at fill up and run to get air out of the tank / lines.

Applied the electric and in a few minutes as the tank heated I got some leaks through the T&P valve. I opened and closed the valve a couple of times. After about 30 to 45 minutes it no longer seems to be leaking. Is this normal on a brand new water heater?

Not normal, no, that is, as long as your building water pressure was at normal limits. Perhaps the valve was not properly seated. For safety I"d prefer to replace the valve as I"m not sure what it might do in the future.

And it is unsafe because eventually the leak can lead to a clogged valve which then could lead to an exploded heater. However it is normal for a little water to drip out of the discharge tube for a moment or two after testing.

In a domestic (North American) water supply system, to the best of my knowlege there is nothing to prevent the expanding water/pressure from the hot water heater from just backing up into the supply plumbing and hence the water pressure in the hot water heater would NEVER exceed the supply pressure.

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"Residential Gas and Electric Water Heaters: Service Handbook", [PDF], A.O. Smith Water Products Company, 5621 W. 115th St., Alsip IL 60803 USA, Tel: 1-800-433-2545, Website: www.hotwater.com, Email: www.hotwater.com/parts, retrieved 15 March 2015, orginal source: : http://www.hotwater.com/lit/training/320991-000.pdf

This handbook provides service information for residential gas water heaters that are atmospherically vented and use a thermocouple as their electrical source and to residential electric water heaters having one or two heating elements and common wiring configurations for these water heater models.

TECHNICAL REFERENCE GUIDE to manufacturer"s model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop Weldon & Associates