Thread: Faulty TP valve

A faulty TP valve messed this one up.



The Daily Item, Sunbury, PA - Faulty valve to blame

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Fritz we (TX) are required (unless an exception applies) to operate the manual lever. Pretty easy to get around doing it with an exception, but if it leaks, it leaks and I did not cause it. The homeowner is supposed to test it at least annually and have a plumber "service" it every three years. The same instruction sheet on the valve tells them to call a plumber if it leaks.
Just like a GFCI, you don't have a problem with calling it defective if it won't reset after you test, right?

I guess anything can happen, but I can't imagine a T&P sticking closed. I wonder if someone might have capped off a leaking drain line?

Originally Posted by Fritz Kelly

Use Jerry's "Failed under testing" (I'm sure that would fly).

It always did.

Here is the key to testing T&P relief valves (do this and it is *HIGHLY UNLIKELY* that you will ever have a problem):

*IF* the valve does not open with limited pressure (go by the Big Box stores and play with some T&P valves and see how little (how much) pressure it typically takes, check yours, your neighbors, friends, family (you will be doing both you and them a favor) *DO NOT FORCE IT*.

A "safety valve" *IS NOT* allowed to be stuck, even once, so don't let a seller, agent, plumber, or 'handyman' say 'well, it works *NOW*' - if it is stuck, write it up for replacement.

If you force you, you could be in for some real surprises.

If, on the other hand, the valve is not stuck, it will release 'easily', and re-seat easily. If a little debris (mineral deposits) keep it from re-seating, open and close it a few times to flush out the debris, and if it does not re-seat, the valve needs to be replaced.

Now, mind you, that's all and good for *the way the T&P discharges used to be when they went outside*, but the new way of flooding the house to notify the owner is different.

I would treat that like I did shower stalls where I could see water staining around the outside of them - call in the agent and say 'The shower pan leaks, see that over there?' When the agent says 'But is it leaking now?", you respond with 'Well, I can check it, but if it I do and it floods the house, YOU will be responsible for cleaning it all up - do YOU really want me to test it?' When they say 'YES, PROVE IT', well, that, ladies and gents is your call to arms to PROVE IT, so do so, and, when it leaks all over, just like you said it would, you point it out to the agent and say 'I guess YOU will be needing some towels.', then walk away and keep on inspecting.

Do that once or twice and they will understand that you mean what you say: 1) it WILL leak; 2) it is up to THEM to clean it up.

Now, just change 'shower stall' with T&P, 'well, it IS old and it needs to be replaced ...', and they say 'PROVE IT ... ' - do so, and when it overflows and makes a mess, it is their mess to clean up.

That was from my old hometown newspaper. Mifflinburg is farm country, about 10 miles from where I was born and raised. It was probably an electric water heater, as there isn't much natural gas out there. Who knows, they could have blocked off the relief valve piping to keep it from dripping. Glad it wasn't anyone I know.

Here is a picture of a relief valve off a boiler , but I have replaced water heater relief valves that looked like this...............

I recently had a water heater explode due to a faulty relief valve. I was away on a trip when it happened and fortunately the water supply was turned off. This is why I'm concerned about a pair of water heaters installed in the attic of a home we just purchased...testing the valves periodically will be difficult with only a scuttlehole access to the attic.

The few times I've test the valves on my heaters, I've had problems getting them to stop leaking....a few flicks of the lever usually cleans the seat and the leak stops. SD

Originally Posted by Steve D'Gerolamo

I recently had a water heater explode due to a faulty relief valve. I was away on a trip when it happened and fortunately the water supply was turned off.

Steve,

I am confused.

"I recently had a water heater explode... "

"fortunately the water supply was turned off."

See my problem?

How can a water heater explode when the gas or electric is off?

Surely you did not turn the water off without turning the energy source off, right?

If you did, then it was likely *not* a faulty T&P valve, it was more likely thermal expansion from the water heater heating the confined water in a closed system with no place for the expansion to take place.

In which case the fault likely lies in not having a thermal expansion tank.

Also, explain "water heater exploded" ... did it "explode", "burst", or "rupture at a seam"? Thermal expansion could do the later two, and, yes, the T&P should relieve the pressure at 150 psi, but a thermal expansion tank would have prevented pressures from getting that high - thermal expansion tanks should not allow the pressure to exceed 80 psi, and there should be a pressure relief to keep the pressure down to there ifs there are other sources of high pressure. The piping system itself is likely to fail due to high pressure if the thermal expansion is not taken up or relieved.

An "exploding" water heater would have destroyed part of the house too, was your house destroyed?

Originally Posted by Steve D'Gerolamo

I recently had a water heater explode due to a faulty relief valve. I was away on a trip when it happened and fortunately the water supply was turned off.SD

Steve,

Did you turn the power source off or just the water main off?

Originally Posted by Billy Stephens

Steve,

Did you turn the power source off or just the water main off?

The gas was not turned off and there was no thermal expansion tank. The tank bottom blew out (40 gallons on the floor) and the vent cap blew up and got stuck in the basement rafters.

Question for you guys....and this applies to another post I have on this forum. I have a vacation house in NC with 2 water heaters in the attic. Both have thermal expansion tanks. When I leave the house for 3-4 weeks at a time, I shut off the main water supply. Is it absolutely necessary to turn the gas off as well??

SD

"Is it absolutely necessary to turn the gas off as well??"

Not if your insurance is paid and there is no family or friends staying in the house.

It is recommended that water heater installations have a thermal expansion tank. One of the factors that contributed to my tank failure was not having one. I now have one in installed with the replacement water heater. The Amtrol unit I purchased came with a factory pre-charge of 40psi and I increased (via the Shrader valve on the bottom of the unit) to 85psi (ie, equal to the supply water pressure).

When you do a home inspection, do you check the pressure on the expansion tank to ensure it is correctly pressurized to protect the heater? I assume an expansion tank with little or no pressure is the same has having none at all. SD

PS - here's a photo of the replacement tank ...the T&P drain tube (not shown in photo) is now in place. The grey sediment on the floor behind the water heater is from the previous unit that "over-expanded" .

Hi Steve, you have thick skin, my congratulations on staying on the forum in spite of some pretty pointed "observations". There is much information to be had here but thick skin is a requirement.
As was mentioned, the gas or electric needs to be turned off if the water is shut down or at least turned to pilot or vacation setting. Off is safest.
No, I don't check pressure on the expansion tanks, but it might not be a bad idea. That is something that should be done at installation and would be beyond the scope of most HI since to properly test or adjust the pressure to the bladder, the water pressure would have to be removed since the bladder in the tank would be compressed by the household water pressure increasing the relative pressure in the tank bladder. Not quite as simple as checking tire pressure even though it is a Schroeder valve.
Stick around, you have some good questions.

p.s. make sure the expansion tank is properly sized for the application, a big heater or dual heaters requires a larger expansion tank.

Steve,

Did you read the attached before install.I see something missing.

Your photo shows signs of water intrusion on your brick wall.

If you Don't know what you are LOOKING FOR you are just LOOKING not Inspecting.

Sorry Steve this is a Knock against you.

Steves photo shows the gas line hooked directly to the water heater.
Isn't a flex line required on this installation?

Originally Posted by Dan Harris

Steves photo shows the gas line hooked directly to the water heater.
Isn't a flex line required on this installation?

Dan,

Black Pipe with a 3in min. drip leg is OK.

Originally Posted by Billy Stephens

Steve,

Did you read the attached before install.I see something missing.

Your photo shows signs of water intrusion on your brick wall.

If you Don't know what you are LOOKING FOR you are just LOOKING not Inspecting.

Sorry Steve this is a Knock against you.

I definitely read the instructions. Not sure what you mean by water intrusion on the brick wall (there was a bit of water in that spot when the previous unit let go). Note that our NJ house is 115yrs old and that wall behind the heater is the backside of the chimney. The water heater supplies hot water to the 2nd/3rd floor. The first floor water heater has been replaced with an indirect unit....see photos below.




Here a link to a larger photo........

http://www.ultimategarage.com/homega...on2display.jpg

I think Billy is talking about,
#1 The T&P valve needs a drain line
#2 (I think) there should be a bracket to support the expansion tank

Steve,

Figure ! installation instructions calls for Back Flow,Check Valve or pressure reducing valve
on the supply side. If it's there I don't see it.

Water Intrusion: If you look at your picture AO Smith Logo look right past Exp. tank and cooper pipes at the staining on the wall behind. Now go up about 6 bricks right under(metal vent?) there is additional staining. The repaired crack behind the cross pipe from WH to Exp. tank could be newer mortar but also might be wet.

Originally Posted by Rick Cantrell

I think Billy is talking about,
#1 The T&P valve needs a drain line
#2 (I think) there should be a bracket to support the expansion tank

I mentioned with the photo that the T&P drain line was not in place when I took the photo. The copper line to the tank is also supported.

Steve,

What about my Post?

Originally Posted by Billy Stephens

Steve,

Figure ! installation instructions calls for Back Flow,Check Valve or pressure reducing valve
on the supply side. If it's there I don't see it.

Didn't see a need for a backflow unit as this is city water with no direct link to a non-potable source of water. I measured 85psi city water pressure at the house, have no water hammer problems and decided not to use any check valves or pressure reducing units.

Plumbing fixtures are pretty forgiving with regard to pressure variations of 10-20%. Yet most electronic devices, control modules, appliances, etc will not work effectively with 5-10% fluctuations in the power supply yet I don't see inspectors and manufacturers calling for voltage regulation in the home. This I feel is important and have four 1000va UPS units (w/AVR & pure sine wave output) throughout the house for all of my network, PC, HVAC controls, TV's etc. The units are also on transfer switch circuits in the event of an extended power outage.

Billy...No leaks on the bricks. There is some staining down low from when the previous water heater dumped its 40 gallons while I was away. SD

Originally Posted by Steve D'Gerolamo

Didn't see a need for a backflow unit as this is city water with no direct link to a non-potable source of water. I measured 85psi city water pressure at the house, have no water hammer problems and decided not to use any check valves or pressure reducing units.

Billy...No leaks on the bricks. There is some staining down low from when the previous water heater dumped its 40 gallons while I was away. SD

Steve,

It looks like you do good work. Don't let the builder in North Carolina tell you he did not see a need to follow Manufacturers Install instructions.

And Get IT Inspected.No joke

Originally Posted by Steve D'Gerolamo

I measured 85psi city water pressure at the house, have no water hammer problems and decided not to use any check valves or pressure reducing units.

Steve,

Install one of those pressure gages which has a max pressure reading hand inside it.

My guess is you will be surprised at what the max pressure that system is under.

Even though 85 psi is only 5 psi above the allowed maximum of 80 psi, continued long term high pressure could cause joints to leak, the weakest joint, probably in a wall somewhere.

I see in your posts you are a knowledgeable and inquisitive man, so, if you would, install a max reading pressure gage, wait a couple of days, and go out and see what the max pressure is, then report it back here ... thanks.

I think your curiosity will have you do it, and I suspect you will be surprised at the max reading.

Originally Posted by Jerry Peck

Steve,

Install one of those pressure gages which has a max pressure reading hand inside it.

My guess is you will be surprised at what the max pressure that system is under.

Even though 85 psi is only 5 psi above the allowed maximum of 80 psi, continued long term high pressure could cause joints to leak, the weakest joint, probably in a wall somewhere.

I see in your posts you are a knowledgeable and inquisitive man, so, if you would, install a max reading pressure gage, wait a couple of days, and go out and see what the max pressure is, then report it back here ... thanks.

I think your curiosity will have you do it, and I suspect you will be surprised at the max reading.

Interesting....80psi seems pretty low. Is the pressure generally regulated right at the meter output (excluding any irrigation system feeds) or only for the supply to the water heater? SD

Originally Posted by Steve D'Gerolamo

Is the pressure generally regulated right at the meter output (excluding any irrigation system feeds) or only for the supply to the water heater? SD

Steve,

At the water service to the house.

(underlining is mine)
P2903.3 Minimum pressure. Minimum static pressure (as determined by the local water authority) at the building entrance for either public or private water service shall be 40 psi (276 kPa).

- P2903.3.1 Maximum pressure. Maximum static pressure shall be 80 psi (551 kPa).When main pressure exceeds 80 psi (551 kPa), an approved pressure-reducing valve conforming to ASSE 1003 shall be installed on the domestic water branch main or riser at the connection to the water-service pipe.

Originally Posted by Jerry Peck

Steve,

At the water service to the house.

(underlining is mine)
P2903.3 Minimum pressure. Minimum static pressure (as determined by the local water authority) at the building entrance for either public or private water service shall be 40 psi (276 kPa).

- P2903.3.1 Maximum pressure. Maximum static pressure shall be 80 psi (551 kPa).When main pressure exceeds 80 psi (551 kPa), an approved pressure-reducing valve conforming to ASSE 1003 shall be installed on the domestic water branch main or riser at the connection to the water-service pipe.

Thanks Jerry. Steve

Originally Posted by Billy Stephens

Steve,

What about my Post?

BILLY,
You guys check more stuff than we do. What SOP do you guys use? I don't check TPRV's.

Originally Posted by Tom Munds

BILLY,
You guys check more stuff than we do. What SOP do you guys use? I don't check TPRV's.

Hi Tom,

I'm licensed in 2 states one follows ASHI standards. The other is below

Originally Posted by Billy Stephens

Hi Tom,

I'm licensed in 2 states one follows ASHI standards. The other is below

Billy,
Are you saying that you do operate the TPRV's? Have I missed something?
Crap! I wonder what else I haven't been adhering to?
I haven't even passed the Nat'l exam yet-I freak on tests, not sure what I am going to do. You guys are so far ahead of me-Iv'e gone to far to turn back now so every day I don't have jobs I'm trying to learn and not be "one of those guys"

There's an old saying:

He who operates TPR valves during a Home Inpection will soon be buying one.

Originally Posted by Michael Larson

There's an old saying:

He who operates TPR valves during a Home Inpection will soon be buying one.

Michael,

I operated them (the ones as I've described to operate) for 16 years - NEVER had to buy one.


I have frequently described how to test them, and which ones to test, and which ones to write up for replacement. The HI should do either of those two things: 1) test it if it feels like it is able to be tested; 2) write up for replacement those which do not meet 1).

Originally Posted by Jerry Peck

Michael,

I operated them (the ones as I've described to operate) for 16 years - NEVER had to buy one.


I have frequently described how to test them, and which ones to test, and which ones to write up for replacement. The HI should do either of those two things: 1) test it if it feels like it is able to be tested; 2) write up for replacement those which do not meet 1).

You must not have hard water down there. Far too often they never get tested around here and if the poor HI tries he can't get it to shut off again.
Been there done that. Your mileage may vary.

The rule of thumb here is either test them monthly or don't test them at all.

Originally Posted by Tom Munds

BILLY,
What SOP do you guys use? .

Originally Posted by Tom Munds

Billy,
Have I missed something? Crap!

Tom,

We all miss something except maybe JP.

As you have referenced ASHI Standard of Practice on another thread thats pretty much my Reporting Standard for one State.

If you read the pdf. file SOP starts page 8 goes through page 23.

Originally Posted by Jerry Peck

Michael,

I operated them (the ones as I've described to operate) for 16 years - NEVER had to buy one.


I have frequently described how to test them, and which ones to test, and which ones to write up for replacement. The HI should do either of those two things: 1) test it if it feels like it is able to be tested; 2) write up for replacement those which do not meet 1).

Is that part of the ASHi SOP?

Originally Posted by Billy Stephens

Tom,

We all miss something except maybe JP.

As you have referenced ASHI Standard of Practice on another thread thats pretty much my Reporting Standard for one State.

If you read the pdf. file SOP starts page 8 goes through page 23.

Thank you. I am more confused about TPRV's now than ever. We do have hard water but I guess it depends on how hard mine is 8g here at my house

Oh, I miss a bunch of things, even told my clients that, also told them I would try to not miss the big things, just the small things.

It's not how *hard the water is* which defines whether or not you test the T&P valve, it is *how hard the valve is to open* which does.

I'll say it again: Go by a Big Box store and test some T&P valves, get a feel for *how hard it is* to open the valves.

Test your own, test those for family and friends. Get a feel of what the valve should feel like.

Then, when testing a T&P valve, *DO NOT FORCE* a valve open. It is a SAFETY RELIEF VALVE, it is REQUIRED TO OPEN WITHOUT EVER BEING STUCK, not even once.

If the R&P opens like you expect it would (like all those new ones you tested and all those of your friends and family), open it, it should close again.

If it 'feels harder' then you expect it should ... DO NOT open it, it is stuck, or sticking, or partially stuck - you need to write it up for replacement (there is no "repair").

Also, write it up with the added information for your client that, if the plumber comes back and says 'well, it is working now', don't accept that - it is a "safety valve" and it should work first time every time, when it does not, it needs to be "replaced", not "forced open" ... if the plumber did not "replace it", then the plumber needs to go back and "replace it" - accept nothing less, it could be your house and your family's lives at stake.

I am always surprised at how many plumber insist on that valve being able to flood the home with water, then are willing to leave stuck or sticking valves in place. When the valve opens, the danger is past, when that valve stick - that is when water heaters explode and destroy homes.

Originally Posted by Steve D'Gerolamo

Thanks Jerry. Steve

Steve,

What was your pressure readings?

Originally Posted by Jerry Peck

Steve,

What was your pressure readings?

I haven't installed in permanent gauges yet but my small gauge with garden hose fitting still shows 85-87 psi. The water company was here yesterday (putting in new RF transmitters so they can drive down the streets and read their customers meters) and he said some towns have way over 100psi and others are much lower (in the 40psi range). SD

Steve,

Do you have one of the small gages with the maximum pressure needle?

If so, put it on and leave it a day or two.

I'm guessing your maximum pressure will exceed 100 psi, and could be even higher.

If the city is telling you they have areas with 100 psi, they should be requiring pressure reducing regulators be installed.

What code is your local area under? I'm guessing that the code in your area probably requires pressure reducing regulators when the pressure exceeds 80 psi.

With copper piping, if there were any pipe ends which were not reamed properly, or any other 'obstructions' to smooth water flow, at high pressure and high flow rates (high pressure provides higher flow rates for the same opening at the fixture), the water flowing over a non-properly reamed cut can do the same thing that wave action does around your feet when you stand in water where there are waves - scours the material (sand/copper) out from around the obstruction (your feet/non-properly reamed cut), weakening the material (causing you to fall/copper to leak).