# T&P leaking



## voltatab (Jan 2, 2010)

This is in my apt building where I'm not the one doing the work, but the maint guy isn't sure what to do( HIRE A PLUMBER! I know I know) 
100 gal WH in a small apt complex, the t&p leaks a small stream of water in the mornings. Changed out the t&p, still leaks only in the mornings.
Put a pressure regulator on it (didn't have one previously) it still streams out in the
mornings. I just noticed they hired a plumber finally who added another regulator on the cold inlet to the WH. (Dont know why, never seen anyone do that) but it still leaks. Pressure is down now to 65psi. 
It has a Recirc that works....what's the next step?


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## AWWGH (May 2, 2011)

voltatab said:


> This is in my apt building where I'm not the one doing the work, but the maint guy isn't sure what to do( HIRE A PLUMBER! I know I know)
> 100 gal WH in a small apt complex, the t&p leaks a small stream of water in the mornings. Changed out the t&p, still leaks only in the mornings.
> Put a pressure regulator on it (didn't have one previously) it still streams out in the
> mornings. I just noticed they hired a plumber finally who added another regulator on the cold inlet to the WH. (Dont know why, never seen anyone do that) but it still leaks. Pressure is down now to 65psi.
> It has a Recirc that works....what's the next step?


Is there an expansion tank on the system?


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## love2surf927 (Dec 22, 2011)

"Put a pressure regulator on it (didn't have one previously)" Do you mean they installed a PRV on the outlet side of the heater, WTH!? What is that supposed to do. "they hired a plumber(?) finally who added another regulator on the cold inlet to the WH." Is there already a PRV on the service to the building, if so what is the second PRV for. Does the heater have an expansion tank on the cold inlet side? When does it stop leaking? Around the time when people might start using hot water? More info please.


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## futz (Sep 17, 2009)

Ya, sounds like expansion. If there's an existing expansion tank, it may be waterlogged (failed diaphragm). Time to replace it, or install one if there isn't one now.

A PRV won't help anything. Waste of money.


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## 130 PLUMBER (Oct 22, 2009)

^^what he said^^


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## GREENPLUM (Jul 27, 2008)

whats the water temp?


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## voltatab (Jan 2, 2010)

Prv on main. Another Prv put on cold inlet above WH. No idea why. 

There is no expansion tank, water temp Is about 140


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## voltatab (Jan 2, 2010)

So the next thing your going to say is lower the temp....and put on an expansion tank on the cold side, right? Will do 


On a side note, they decided to hire me to fix the prob, since everyone was picking my brain bout it anyway. I told them "I'd love to help but I have work to do...but if you want to pay me I can put you on the schedule"


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## Mississippiplum (Sep 30, 2011)

Take the prv off the heater that the "plumber" installed on it and install an expansion tank, install a new t&p also

And turn the temp down or install a tempering valve. Someone will get burned, and it will be on u cause u were the last 1 their working on the heater. 

sent from the jobsite porta-potty


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## PlumbPerfect (Jan 11, 2012)

an expansion tank on the cold side or a thermal expansion tank on the hot?


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## ZL700 (Dec 8, 2009)

A potable water expansion tank set at the proper air charge on the cold water line near the inlet of the water tank. 

Amazes me how many plumbers don't know or havent heard of domestic thermal expansion.


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## Widdershins (Feb 5, 2011)

*I concur about the expansion tank.*

The only happening in the morning aspect doesn't make sense.

Mornings are a peak time where water pressure is expected to go down, not up.

And I'd definitely dial the temperature down, especially if you will be doing work on the tank -- Working on the tank gives you an ownership stake in the tank which also gives you liability.


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## voltatab (Jan 2, 2010)

Will do


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## Widdershins (Feb 5, 2011)

voltatab said:


> Will do


 Is there backflow prevention (RPZ) on the system which is preventing the pressure built up from thermal expansion from bouncing back into the supply from the purveyor?


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## drain surgeon (Jun 17, 2010)

As everyone has said An expantion on the cold inlet with the tank pre pressurized to the incoming water pressure


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## voltatab (Jan 2, 2010)

No backflow prevention that ive seen. But they aren't required out here on resi 

Well they just called me and said they are hiring someone who can come out sooner, earliest I can make it is tomorrow afternoon... F these guys. At least now I know a couple more steps to take in this instance - as always, thanks everyone.


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## Widdershins (Feb 5, 2011)

voltatab said:


> No backflow prevention that ive seen. But they aren't required out here on resi
> 
> Well they just called me and said they are hiring someone who can come out sooner, earliest I can make it is tomorrow afternoon... F these guys. At least now I know a couple more steps to take in this instance - as always, thanks everyone.


Count yourself lucky -- Being the 'Resident Plumber' who lives onsite can be a real pain in the arse, especially if you're a family man who enjoys his evenings with his family and a good nights rest.

My youngest employee finally had to tell the property management firm who manages his apartment building to lose his phone number. Too many late night phone calls made his normally sweet Wife a bit of a Shrew.:laughing:


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## ZL700 (Dec 8, 2009)

Widdershins said:


> The only happening in the morning aspect doesn't make sense.
> 
> Mornings are a peak time where water pressure is expected to go down, not up.
> 
> And I'd definitely dial the temperature down, especially if you will be doing work on the tank -- Working on the tank gives you an ownership stake in the tank which also gives you liability.


Highest hot water draws are in the mornings bringing in the coldest water, all the makings of thermal expansion while fired.


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## Widdershins (Feb 5, 2011)

ZL700 said:


> Highest hot water draws are in the mornings bringing in the coldest water, all the makings of thermal expansion while fired.


Makes sense. Thanks.


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## futz (Sep 17, 2009)

voltatab said:


> So the next thing your going to say is lower the temp...





Mississippiplum said:


> And turn the temp down or install a tempering valve. Someone will get burned, and it will be on u cause u were the last 1 their working on the heater.


And DO NOT turn the temp down. 140F is the proper temp. *A*. Because it's only 100 gallons split between who knows how many units and people. Hotter water stretches farther. Turn it down and they'll be whining about running out of hot water during peak periods. *B*. Because 140F inhibits bacteria growth (Legionella Pneumophila) in the tank and waterpipes. Any temperature below 140 may not.

From the OSHA Technical Manual:


> CONDITIONS THAT PROMOTE GROWTH.
> L. pneumophila bacteria are widely distributed in water systems. They tend to grow in biofilms or slime on the surfaces of lakes, rivers and streams, and they are not eradicated by the chlorination used to purify domestic water systems. Low and even nondetectable levels of the organism can colonize a water source and grow to high concentrations under the right conditions.
> 
> Conditions that promote growth of the organism include heat, sediment, scale, and supporting (commensal) microflora in water. Common water organisms including algae, amoebae, and other bacteria appear to amplify Legionella growth by providing nutrients or harboring the organism. Because of its ability to remain viable in domestic water systems, it is capable of rapid multiplication under the proper conditions.
> ...


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## user7551 (Oct 21, 2011)

All of the water heaters we install the temps have to be set at least 140 degree's minimum.


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## Redwood (Sep 8, 2008)

A T&P Valve will open and leak under 3 conditions:

*Temperature* usually 210-degrees F but may be different depending on the specifications of the valve.
*Pressure* usually 150 PSI but may vary depending on the specifications of the valve.
*It's Faulty!*

As a plumber you should have the means to measure temperature & pressure to determine why the valve is opening. I'll agree that it probably is thermal expansion but measuring the pressure while the tank is heating would tell you all you need to know...

Or, you can just make a wild azzed guess and throw parts at it until the problem stops or the customer tells you to get lost...

As for temperature if you are setting higher than 120 degrees I hope there is a tempering valve providing anti-scald protection...

Look for the 140 degree temperature cited by Futz to be in your code update soon along with anti-scald protection...


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## MTDUNN (Oct 9, 2011)

Check temp and pressure as it heats. Install expansion tank. Check for sediment build up at the control valve level it can give a false reading on the control valve.


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## voltatab (Jan 2, 2010)

Well I just got home and found that the maint guys REPLACED the water heater....


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## LEAD INGOT (Jul 15, 2009)

Well when it happens again tomorrow morning, they will totally be able to rule out the water heater and it's componants. Friggan maintance guys, sheesh.


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## voltatab (Jan 2, 2010)

I've decided not to s**t where I eat, and Turn down any work in my complex...but I still can't help popping in the utility room to see what they've done

no disrespect to anyone here who doesn't see value in uniforms, but the plumber that they called out showed up in a tanktop shorts and flip flops. Not exactly a pro, no wonder he didn't know what to do


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## TPWinc (May 30, 2011)

voltatab said:


> the plumber that they called out showed up in a tanktop shorts and flip flops.


You caught me, but atleast my logo, license and phone number are printed on my tanktop!


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## voltatab (Jan 2, 2010)

Different areas call for different dress codes, but that's technically a uniform if its company issued or has your info on the shirt.

I thought the guy just wandered off the street and wanted to plumb!


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## 89plumbum (May 14, 2011)

TPWinc said:


> You caught me, but atleast my logo, license and phone number are printed on my tanktop!



Don't you mean your "suspenders"! :laughing:


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## AlbacoreShuffle (Aug 28, 2011)

voltatab said:


> Well I just got home and found that the maint guys REPLACED the water heater....


I'd call the city to see if a permit was pull, If not Id narc on um !


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## Redwood (Sep 8, 2008)

voltatab said:


> Well I just got home and found that the maint guys REPLACED the water heater....


Well from now on their wild azzed guesses are cheaper.... :laughing:


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## bizzybeeplumbin (Jul 19, 2011)

so what happended? Was the new tank installed with an expansion tank? I know they are in the UPC but are rarely called upon by inspectors or other plumbers. I do know that the water dept out there has been upgrading the meters for a number of years and the new meters have check valves in them not allowing the expansion to go back through the city meter. Here on the right coast, every meter has a double check. This is a really good reason to require an expansion tank.


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## damnplumber (Jan 22, 2012)

GREENPLUM said:


> whats the water temp?


BINGO! TPRV= thermal pressur relief valve if the pressure is safe, check temp.


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## voltatab (Jan 2, 2010)

No more leak for now. they also added a new Recirc with it

No expansion tank added...but at least the additional press reg that was right above the cold inlet was removed haha


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## voltatab (Jan 2, 2010)

I've never installed a commercial heater before. 

What the hell is that thing in the bottom?


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## voltatab (Jan 2, 2010)

Also. This is the t&p line that goes to outside the utility room. 

That's the whole that was created by the scalding hot water blasting into the asphalt.....on its way to china!


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## AlbacoreShuffle (Aug 28, 2011)

voltatab said:


> I've never installed a commercial heater before.
> 
> What the hell is that thing in the bottom?


Thats a hair dryer for the rats that live in the utility room.


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## AlbacoreShuffle (Aug 28, 2011)

Was that water heater permited and inspected ?

If that was in California , it would not pass inspection for lack of blocking between the wall and the water heater.


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## voltatab (Jan 2, 2010)

It was in Cali. Assuming no permit


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## AlbacoreShuffle (Aug 28, 2011)

voltatab said:


> It was in Cali. Assuming no permit


You should fink him out.

UPC clearly states that ALL water heater installs SHALL be permitted.


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## MikeS (Oct 3, 2011)

I bet I know what happened, looking at the pics. First t&p was replaced, and since it was a soldered copper line, someone soldered too close to the t&p. Get that t&p too hot, it'll melt the the washer in there.


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## MikeS (Oct 3, 2011)

voltatab said:


> Also. This is the t&p line that goes to outside the utility room.
> 
> That's the whole that was created by the scalding hot water blasting into the asphalt.....on its way to china!


 
scalding hot water? So the temp was above 200 degrees? Then it would be a failed control valve or thermostat, kept the heater on beyond the thermostat setting!


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## user7551 (Oct 21, 2011)

Redwood said:


> A T&P Valve will open and leak under 3 conditions:
> 
> *Temperature* usually 210-degrees F but may be different depending on the specifications of the valve.
> *Pressure* usually 150 PSI but may vary depending on the specifications of the valve.
> ...



Let me clarify , all the commercial water heaters we install are set at 140 degrees and yes all hand sinks and restroom lavatories have tempering valves on them.


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## bizzybeeplumbin (Jul 19, 2011)

no blocking behind the heater, no no in California. I love seeing those heaters in laundry rooms, that screen over the fan gets blocked with lint and the unit wont fire. On top of that, I have done a number of pressure switches for those heaters. Easy money when the tenants of numerous apts don't have heat :thumbsup:


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## HonestPlumb (Jan 25, 2015)

bizzybeeplumbing- I live New Jersey, it won't pass inspection without expansion tank here. Whether they have thermal expansion or not, it has to be there. Kind of ridiculous to make someone pay for something they do not need. We have been putting them on for 20 or so years though in certain areas, have one town close by that has 175#'s in the street. I agree with Redwood, three diffferent reason a relief valve blows off. Pretty simple to diagnose.


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## rwh (Dec 17, 2014)

Off topic, how do they achieve 175 psi on the city main?


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## wyrickmech (Mar 16, 2013)

rwh said:


> Off topic, how do they achieve 175 psi on the city main?



Hight of tower most of the time.


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## rwh (Dec 17, 2014)

So would be in areas with decent elevation changes on the same water system, plus water tower? Or just a tall tower? 60psi at basement level would be about average here. It is also a very flat county. About 700' above sea level, couple hundred feet variance over aapproximately 40x40mi area. Not muchmore over a 100x100mi area


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## wyrickmech (Mar 16, 2013)

There are variables how close to the tower you are is a large one. The closer to the tower you are the lower the pressure. The farther you are the more potential for increase from water weight and water column Increase.


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## wyrickmech (Mar 16, 2013)

Your problem isn't with the water tower you have one of two problems. One no thermal expansion tank or failed or two pressure regulator not fully closing under no use. If you have hi water pressure you need to make sure that the operating pressures are in range with conditions or a new one will do the same thing. Put Gage's on both sides so you can see what's really going on.


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## SubparMarioBro (Oct 10, 2015)

rwh said:


> Off topic, how do they achieve 175 psi on the city main?


Mountains. When I worked in fire I saw some places at the bottom of a canyon with a water source way up the road near the top of that canyon. Ridiculous pressure at the bottom.

We'd sometimes do downhill hoselays and get gravity-feed pressures up to about 300psi. I'm sure we could've gotten them a lot higher but that's about where the hose bursts.


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## HonestPlumb (Jan 25, 2015)

Agree with the majority. I live in an area that has 175#'s in the street. The expansion from the water heating has no where to go. It relieves at the relief valve. The tank is to be installed on cold side between pressure reducing valve and shut off at water heater. Usually at cold piping above shut off on water heater. Did anyone realize that you are supposed to charge the Thermal expansion tank according to some specific parameters ? I know it used to have to be charged to the working pressure of house. Now I think that has varied slightly. Anyone know anything about that?


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## ItalStal (Nov 12, 2015)

3/4" plug should stop the leak.













please dont do this.


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## ItalStal (Nov 12, 2015)

HonestPlumb said:


> Agree with the majority. I live in an area that has 175#'s in the street. The expansion from the water heating has no where to go. It relieves at the relief valve. The tank is to be installed on cold side between pressure reducing valve and shut off at water heater. Usually at cold piping above shut off on water heater. Did anyone realize that you are supposed to charge the Thermal expansion tank according to some specific parameters ? I know it used to have to be charged to the working pressure of house. Now I think that has varied slightly. Anyone know anything about that?


tet air is charged equal to system pressure with no water pressure in the tank


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## HonestPlumb (Jan 25, 2015)

ItalStal- You are correct. I just attended a "Tacco" sponsored class at my supply house. It is the same procedure with a hot water heating system tank. With the heating system expansion tank, you put the pressure in the tank based on static pressure of system or head pressure. Tacco (while I am not a big fan, especially the older version zone valves) have come out with some pretty cool controls. They have a circulator pump that you can just dial what you want for a "Delta T" and it has two sensors, one on feed and one on return and will adjust speed of circulation to achieve the Delta T you chose. They also have come out with a zone valve that only uses current to open and close. You can put 8 zone valves on one 40VA transformer. It is a full port ball zone vale. I still like my Honeywell's as of now. It "is" amazing how a properly designed heating system can require a much smaller boiler when designed properly, and with some of those controls(which are not cheap). What you save on the boiler and efficiency, outweighed the extra cost of the controls, at least on paper ! 
Sorry to get off topic !


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