Relief Valve Leak Diagnostic FAQs

Water coming out of relief valve
Causes & Repairs

TPR Valve Drip or Leak Diagnostic Q&A

Are relief valve leaks ever normal?

Water incoming supply turn on during test. Pressure relief valve open manually. Water drip from pressure relief valve. Is it normal? (Dec 14, 2016) Heater

Reply: No

No, Heater, it is not normal for the pressure relief valve to be leaking.

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.

There is a constant discharge or leak from my water heater pressure relief valve

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.

What other problems could cause this? I have just paid this plumber $500.00 and still have the same problem. I am in the hydraulic industry and very well understand pressures and flows and never did believe a relief set at 150 psi would open at 60 psi. (Apr 20, 2014) John L

Reply:

John I don't understand the 'worn seat" in a temperature/pressure relief valve - but then I'm not on the scene.

A temperature/pressure relief valve does not normally open nor cycle open and shut frequently, so "wear" ought not to be a factor.

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.

More likely there is a cause of overpressure that needs to be found and corrected.

Check first that the water heater is operating at a normal temperature and pressure and that you don't have a water hammer problem.

Then see these diagnostic articles

• THERMAL EXPANSION TPR VALVE LEAKS
  
  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.
• RELIEF VALVE LEAKS - all causes of TPRV leaks

Water heater TP relief valve leaks after switch from well to city water

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. (May 21, 2015) Gary W Barbour

Reply:

Interesting thoughts, Gary.

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.

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

ELECTRIC WATER HEATER ELEMENT TESTS inspectapedia.com/plumbing/Electric_Water_Heater_Element_Test.php

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.

See WATER HAMMER NOISE DIAGNOSE & CURE inspectapedia.com/plumbing/Water_Hammer.htm

and see WATER PRESSURE MEASUREMENT inspectapedia.com/water/Water_Pressure_Measure.php

to actually measure the building water pressure. If the incoming pressure is over 70 psi I'd certainly want a regulator installed.

Keep us posted - what you find will help other readers.

Tankless water heater randomly shoots out water like a hose - high city water pressure?

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?

Is this common and the common fix? (Sept 8, 2016) Marcy K

Reply:

Yes. In addition to excessive water pressure or unsafe water temperature, water hammer can cause relief valve discharge or leaks.

See WATER HAMMER NOISE DIAGNOSE & CURE

Leaks at the relief valve when we take a shower

When we take a shower the hot water drips out of the pressure relief. what is the problem is the temp set to high? (Oct 3, 2016) richard

Reply:

I would look for a problem with temperature set too high, thermal expansion, or water hammer.

See THERMAL EXPANSION TPR VALVE LEAKS

See WATER HAMMER NOISE DIAGNOSE & CURE

See WATER HEATER TEMPERATURE TOO COLD or TOO HOT

Can a handheld shower head, with shut off valve, cause temperature release valve on water heater to open?

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? (Mar 1, 2016) David

Reply: No, but other conditions can cause TPR valve leaks: that's unsafe

David

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.

Search InspectAPedia.com for WATER HAMMER NOISE for details.

David said:
... thanks for your input on my situation with our water heater TPR valve.

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.

The only other information I could provide is that I did turn down the water heater temperature, again to save money.

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?

Causes of leaks at a water heater TPR valve are discussed at

• RELIEF VALVE LEAKS - all types of TPR valves
• RELIEF VALVE, WATER HEATER - TPR valves on water heaters

Reply: hissing at the shower head?

David

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 )

If you are hearing hissing at the shower head after turning water off at that fixture, that's a new one on me and I'll have to do some research.

David said:
... 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.

My water heater thermostats are set at 125 degrees, so I have a tendency to this it's pressure.

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?

Reply: check building water pressure

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.

I doubt the shower head noise is related to temperature.

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.

Surely hissing at the shower head is independent from hissing noises at the water heater.

Reader follow-up: excessive building water pressure caused TPR leaks

... thanks again for all your help. After I replied to you last time (anonymous).

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. 2016/03/27 David

Reply:

David,

Indeed 110 psi input water pressure at a residential building is too high. Pressures over 70 psi invite plumbing leaks at various fixtures.

At inspectapedia.com/plumbing/Hot_Water_Expansion.php

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.

Details are at WATER PRESSURE REDUCER / REGULATOR

Electric water heater keeps spilling at the relief valve - is it a plumbing problem?

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.

The plumber had tested the pressure and it is good. My water heater is just 3 yrs old. Thanks for advice. (Nov 25, 2014) K Young

Reply:

K Y

Your hot water heating system may need its own expansion tank.

See HOT WATER EXPANSION TANKS  for details.

TP Valve leaks where attached to water heater

Installing a new TPV into the top of a five-year old GE water heater. Used pipe dope but there is water pooling around the base of the valve.

I'm cranking with a 12-inch crescent wrench, and getting 20-30 degrees of rotation per mighty heave. Afraid to overtighten and not sure how much is too much. Advice? On 2018-01-13 by George

by (mod) - water pooling around the base of the relief valve.

I would pull out the TPR valve and start over with more turns of new pipe dope or teflon tape, after checking that the threads of the tank tapping have not been damaged or stripped.

I see water leaks at the TP valve mount

Water smears out of the water tank body where TP valve is connected. What should I do? (Sept 29, 2016) Mike

Reply:

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).

Water heater is installed in a cupboard, TP valve dripping

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? - (June 23, 2014) Noel

Reply:

Noel,

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).

Temporarily, put a bucket under the end of the discharge tube so you're not also flooding the floor.

Then call a plumber to diagnose and fix the trouble.

Why do We have a huge water bill,? We think it's due to leaks at the pressure/temperature relief valve

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.

He said that when the water get to hot it releases I assume through the TRV (temperature relief valve).

This would be the cause of excess water as it would then refill.

Just wondering if anyone can confirm and give me some tech details. The realestate is giving us a hard time. On 2019-09-17 y Sarah Lagasse

by (mod) -

Sarah

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.

I don't understand your phrase "The realestate is giving us a hard time", but I warn that whoever that is, the are risking severe building damage and personal injury to anyone who may be in or even near the building where the conditions you describe exist.

Please clarify and keep me posted.

Is it ok for the TP valve to drip or leak just a little bit?

In a plastic container I'm getting about 4oz of water from the TP valve discharge tube. Should I be concerned? - On 2019-11-10 by Joe Alessi

by (mod) - No that is not safe

Joe

Watch out: you should be concerned - the water heater (or boiler) to which the dripping TRP valve is connected may be or may become unsafe.

The risk includes destructive, even fatal BLEVE EXPLOSIONS.

Please read RELIEF VALVE LEAKS for details and let me know if any questions remain.

Water is flowing out of the relief valve discharge tube - do I have to replace the relief valve?

There is water FLOWING from the DISCHARGE TUBE on my Triangle Tube, indirect fired water heater. (I shut of the water supply off to the tank so it isn't spilling onto the floor.) Does this suggest that I need to replace the T&P relief valve? On 2015-12-16 by Paul

by (mod) - possibly, but first, for safety and economy, we must identify the leak cause

Paul.

Watch out: This condition is unsafe. At its extreme, a leaky relief valve can clog, leading to a BLEVE EXPLOSION. (Search InspectApedia.com for that term)

Turn off the boiler to avoid damaging it.

The problem could be the valve but more likely a boiler over pressure condition or a water feeder problem.

Diagnose the cause of the TPR valve discharge before replacing parts.

Whenever I put more than 26 psi into my boiler the relief valve spills

Pressure release valve popped. Water everywhere since I was at work. I replaced the valve and drained all the water from the expansion tank, no bladder.

When I try to refill the system the pressure goes above 26 or so and the valve blows. It will not let me refill the system with water. Any ideas. Thanks On 2017-03-15 by Rick

by (mod) - relief valve leaks after draining expansion tank and installing new valve

Pressure release valve leaks can be caused by several things, as we cite

at RELIEF VALVE LEAKS

Once you're sure that there is a normal air charge in the heating system expansion tank,

then if I'm right in guessing that we're discussing a hydronic (hot water) heating boiler, not a steam boiler, I'd start by checking that the cold boiler pressure is normal - usually around 12 psi and that pressure doesn't creep up even when the boiler is off.

Then I'd look for a water hammer problem.

 

Pressure release valve is leaking at 20 psi. What's wrong?

Release valve leaking. Pressure is 20. Can't figure out what is wrong. On 2017-03-15 by Trevor Humphreys

by (mod)

Trevor:

If the TP valve is leaking and system pressure is well below the pressure at which the valve should be leaking, AND if the pressure reading is accurate (you can test that by making an independent measurement of boiler pressure)

then the valve is probably defective and needs replacement.

A more subtle cause of TP valve leaks that will be intermittent is a water-hammer problem anywhere in the plumbing or heating system.

The article RELIEF VALVE LEAKS lists the likely causes of a leaky TP valve. Please take a look at those and let me know what you find or what questions remain.

Pressure in my heater goes up to 80 psi and the release valve leaks. What's wrong?

Replaced the pressure release valve and lowered the water pressure to 50 sometimes it still goes up to 80 and the release valve still leaks. What do I need to do ? On 2016-10-09 by Bonnie

by (mod) system pressure goes up to 80 and the relief valve still leaks

Bonnie

I'm unclear about what equipment you're working on, where you reduced pressure, and other key matters.

If you are talking about leaks at a heating boiler that uses a tankless coil, house water could be leaking into the boiler through the coil;

or an automatic water feed valve at the boiler may be defective; or a house main pressure regulator may be bad. that's enough shotgunning with so little info.

Watch out: the situation you describe is unsafe and risks a boiler explosion or BLEVE

 

Boiler water is flowing out of our boiler through an outside pipe

We have a mains boiler but from steam pipe which is outside, there is water flowing too much and pressure is going down pleas tell us what to do (Mar 22, 2015) Diljit singh SARNA

Reply:

Dijit I'm sorry but I don't understand the question.

You may be saying the automatic water feeder for the boiler is not shutting off properly or you may be describing a condensate return piping problem.

Or it may be that a boiler pressure relief valve was piped to outside and is spilling

Watch out: these conditions sound to me as if your heater is unsafe and should be shut off.

Have you called your heating service company?

I would turn off the system and make that call.

To understand the dangers of pressure relief valve leaks

see RELIEF VALVE LEAKS

Why is the relief valve leaking on a boiler if the pressure gauge says zero?

I'm working on my friends boiler. The pressure relief valve is leaking. Yet the pressure on the gauge said 0.

Temperature is still at 180 so I assume the expansion tank is still good?

Maybe just a bad relief valve? On 2016-05-16 by Eddie

by (mod) - pressure gauge at zero and temperature at 180 deg means one of those indicators is not working

Eddie

If the pressure gauge says zero and the temperature at 180 something is not working.

If there is water in the boiler and the gauge is working properly the TPR should not be leaking at 180F unless the water feeder valve or pressure regulator are overpressurizing the boiler.

Start by replacing the gauge and the TPR valve.

Watch out: if you're not trained and make a mistake the risk is blowing up the home or burning it down.

by Eddie

This all started when I installed a mixing valve on the domestic coil size as it didn't have one. They were getting boiler water in the shower, sink, etc. Anyways, when I turned the system back on. Thats when the issue arose. The valve drips all the time

. When the boilers at 15 psi or 0. I installed a new TPR valve and it stopped. But when I opened it to test the new valve, the dripping started again. The gauge works. The fill valve may be faulty from I saw today while trouble shooting.

And the expansion tank is the bladder style. I'll also add that the expansion tank spit a bit water when I pressed on its "pin".

I'm going back tomorrow to check the expansion tanks psi and replace it if need be. My friend is really pushing to not change the fill valve as his "boiler guy" told him he didn't have too. Sorry for the long winded story. Just seems to be a new issue every day and I'm trying to get the best advice possible. Thank you

by (mod) - more causes of relief valve drips

A drippy TP valve risks a BLEVE explosion as one day the mineral build up from water passing through the valve may simply clog it up. So replacing it is smart.

Check for a failed diaphragm in the water feeder/pressure reducer

Check for a failed expansion tank

How can I find the cause of relief valve leaks at my new steam boiler & hot water tank?

I had a new oil fired, tankless, steam boiler installed and the existing hot water storage tank was re-used/left in place.

In less than one week the circulator pump sprung a leak (it was actually spraying all over the place) and once that was fixed, the TP valve sprung a leak the same day.

The plumber says these leaks "merely" happened because the storage tank was not replaced along with the boiler, but I think this sounds very fishy - it sounds like way too much of a freak coincidence that both of these components would fail back to back, within days of replacing the boiler.

The storage tank and pump were 7 or 8 years old at the time of the boiler replacement, and as far as I know the TP valve was also replaced with the tank and pump, but I am not 100% certain of that.

Any ideas what the root cause of the pump and TP valve leaks could be?

many thanks!!! On 2015-12-14 by Lisa

by (mod) - find out why a TPR Valve is Leaking

Lisa

I can't tell the cause of the leaks you describe from just an e-text, but certainly it is true that a bad expansion tank can cause relief valves to release hot water. That's not at all the same as a leak at a piping connection.

Water coming out of the relief valve discharge tube is in response to an overpressure condition in the system.

That might be caused by a waterlogged expansion tank, explained

at RELIEF VALVE LEAK DUE TO EXPANSION TANK

Leaks where the valve screws into the boiler are a plumbing problem.

Leaks at a circulator would more likely be a bad gasket, connection or mounting problem.

by Lisa

Hi danjoefriedman

I appreciate the quick response. The thing that concerns me is that they didn't do any work on the pump or the relief valve!

These were installed several years ago, had no problems, the plumbers said it was ok to keep that part of the system in place so as far as i know they didn't touch it.

The fact that both of these parts started leaking within days of replacing the boiler makes me worry there is a more serious problem. Like too much pressure in the system ;)

by (mod) - what causes the relief valve to leak if it's not the expansion tank?

If the expansion tank is found to be NOT defective (not waterlogged or for newer tanks, NOT to have a burst bladder) then yes one would next check the system pressure regulator / water feeder.

Basically IF you see boiler water pressure over 30 PSI when the boiler is hot, the pressure is too high.

Most systems also show about 12 psi - certainly under 20 psi - for residential homes when the system is cold.

Call your heating service company. LEe me know what you're told.

by Lisa

This is so helpful - thank you! and yes I will report back.

Unfortunately I'm not living in the house so I have to wait for my tenants to get back to me about the pressure reading, then I'll proceed from there.

by (mod) - Watch out: A leaking temperature/pressure relief valve is UNSAFE.

Lisa

Watch out: A leaking temperature/pressure relief valve is UNSAFE.

Over time water leaking through the valve body can leave mineral deposits that clog the valve, ultimately meaning it may not properly respond to an unsafe condition such as boiler over pressure or over temperature.

In turn that can cause a dangerous BLEVE explosion.

So if the valve is still leaking at your system you want to have a heating service tech out to the property promptly. Don't panic, but don't be unsafe either

by (mod)

Review the common TP valve leak causes at RELIEF VALVE LEAKS

I'd be very interested if your boiler's TP valve leaks was not one of those.

Sometimes a TP valve leak cause is not so obvious, such as water hammer, surges in boiler temperature due to an aquastat problem, surges in boiler pressure due to a problem in the water pressure regulator or feeder, or even a leak in the tankless coil on a boiler.

by Lisa

I don't have any less and the pressure and the gauge says 40 psi. What's the problem

by (mod) - If the boiler pressure is over 30 psi the TP valve SHOULD be dumping

Watch out: If the boiler pressure is over 30 psi the TP valve SHOULD be dumping to avoid a potentially fatal BLEVE explosion of your boiler.

Your system needs service: the problem can be at a pressure reducing valve, water feed valve, leaky tankless coil, or something else.

by Lisa

Just to follow up: the TP valve seems to be fine, there has been no sign of further leaks.

The boiler pressure was also very low so for now it looks like the problem is resolved.

I still find it troubling that these parts on the storage tank failed within days of the boiler installation, but I don't think I'll ever really be able to get to the bottom of it.

Thank you so much for your advice!

Yes I know - these parts failed last week, so the pump was replaced last thursday, and the PT valve was replaced on friday. I'm waiting to hear from the tenants if there is any evidence that the valve is leaking again, if there are any other leaks, and what the pressure gauge says.

Based on that info (and your advice so far) I will move forward. Believe me, I'm not taking any chances with this.

Steam "pop valves" have a seal that shows if the valve has been tampered with

Steam pop safety valves have a tamper proof seal attached to detect whether the valve has been tampered with.

As per the ASME CODE, only the manufacturer of the valve may repair or re-adjust the safety valve. In almost every case the safety valve that leaks is already damaged.

Watch out: Continuing to operate a boiler with a leaking safety valve may result in a boiler explosion. On 2015-08-07 by John Tedesco

by (mod)

Thanks for your comment, John. We agree that it is crazy, and very dangerous, to make try a "DIY" repair to a TP valve on heating equipment.

Watch out: most of us who've worked in the field have seen some pretty crazy and scary modifications ranging from plugs and valves to "fix" a leaky relief valve

Watch out: (DO NOT DO THAT or YOU MAY KILL EVERYONE NEARBY) to use of drips from the TPR valve to water the cat bowl.

I replaced a defective pressure relief valve - Is it tight enough?

I put in a new water heater and when it came the pressure relief valve was bent and defective.

The place I bought it gave new pressure relief valve I put it in but did not tighten it as far as it could go in because than I would have a problem of putting the line into pressure relief valve.

I can turn it by hand but with line in you can not turn it.It does not leak and valve works.will this be a problem down the road? (Apr 21, 2014) Jeff

Reply: if you can turn the TPR valve by hand, it's too loose

Jeff, I am nervous about promising the safety of such a critical device in a DIY installation that I cannot see.

If the valve is easily rotated by someone bumping the TP valve extension tube it's too loose. Or, as up surmise, it's too loose if it leaks.

But I understand very well the problem of where you end up when rotating the TP valve into place on a heating appliance, as we for sure want the valve body facing down.

When I have this problem I add a couple of loops of teflon tape so that the valve will snug up a bit sooner. (Check the installation sheet to confirm that the manufacturer allows use of teflon tape on their valve.)

Check the valve several times over the next week with the heating system at full operating temperature and pressure - looking for leaks and check again at periodic service or if you see mineral salts build-up around the valve or water on the floor or boiler side.

or

Replace the TPR valve with a new one, use teflon tape and be sure the valve is tightened with a wrency at least 1/4 turn beyond what you can do by hand.. This would be the safer option.