Hot Water Heater T&P Valve Drip


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Old 12-05-13, 06:46 AM
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Hot Water Heater T&P Valve Drip

I had a new Bradford White hot water heater installed in April of 2013 not sure of the model number, but it is a 40 gallon gas (atmospheric vent I think)...less than a year ago. I recently noticed that water was accumulationg on the floor, not a lot, just a little puddle usually only once a day or less. Process of elimination determined that the T&P valve drips. Not constantly, usually after a shower or a lot of hot water has been used. I tested this out by going down and seeing it not leaking, ran hot water in a nearby utility sink full blast for maybe 3 minutes. While the water is running there was no drip, however after I had stopped running the water the drip started. I'd say maybe a minute to a minute and a halfe elapsed before the drip started. I called the plumber that did the install and here's what he had to say.

After checking the water pressure at the utility sink he says pressure is too high and it is causing the tank pressure to rise and subsequently the T&P vavle drip. He wants to install a pressure reducing valve (I assume) to lower the pressure at a cost of $675. I should add here that I was not home when he checked everything out, my mom was over babysitting so this got relayed to me. He did not leave a written estimate, just told my mom to have me call so I am not sure what specific part he wants to install. She did tell me she saw the gauge on the line but not the exact pressure number it displayed.

Of course I am questioning all this, for a few reasons I'm hoping all you experts here can help me out. I would assume that if the pressure is too high the valve would leak all the time, the pressure doesn't change (except thermal expansion I'll get to that in a sec lol) and if anything I would expect the pressure to increase as the tank is "working". Am I correct in this thinking?

After he came I started doing more investigations, the price for this work is almost the same as what I paid for the water heater so I am just pretty sure he's way too high on the price. When I started looking into things I found on the Bradford White website that all their tanks are tested at 300 psi and certified working pressure is 150 psi. My water pressure would have to exceed the 150 psi in order to cause the valve to leak, correct? Unless of course the T&P valve has bee set to a lower setting if that's possible. The T&P vavle came attached to the tank already when purchased.

I then checked the manual for the heater, it says that this heater should not be installed in a home with a backflow preventer or closed water system without providing a means for thermal expansion relief. When he was installing I did ask whether or not an expansion tank was needed, ether by code or for safety he said no. However I do have a backflow preventer on the water inlet since the home also had well water at one time, I don't use it, but I was told since it comes into the house we are required to have the backflow preventer.

Based on all this I assume an expansion tank is really what is needed not pressure reduction. Am I right? What I don't know is if I need both the pressure reducer and expansion tank or just one of these. I also checked around and the highest priced pressure reducer I found at Lowe's was $150 is the price he quoted way outta line as I suspect? What should it cost to get the expansion tank installed? I see those are only around $40. And Last, am I wrong to feel that this work should be done eother at a very discounted rate or even free since they are one's that screwed up the install?

Sorry for the long post I tried to get as much detail as possible in one shot for all of you.
 
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Old 12-05-13, 07:16 AM
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I'm too lazy to read your entire post but both a pressure reducing valve and an expansion tank probably should be installed. If you question the person that came to give you a price get quotes from several others. That would let you know if the $675 is out of line. In some situations I would say it's way high but you'rs could be a difficult install in which case the price could be justified. Also, pressure gauges are inexpensive and you can pick one up at most home centers and check the pressure yourself.
 
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Old 12-05-13, 07:18 AM
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I would expect the pressure to increase as the tank is "working". Am I correct in this thinking?

Yes


My water pressure would have to exceed the 150 psi in order to cause the valve to leak, correct?

Yes... But they may drip at a lower pressure... Its only a spring in there..

Also the relief valve will drip from high temperature...

However I do have a backflow preventer on the water inlet since the home also had well water at one time, I don't use it, but I was told since it comes into the house we are required to have the backflow preventer.
Is this a backflow or pressure reducing valve? Any pictures or part # to post?

Based on all this I assume an expansion tank is really what is needed not pressure reduction. Am I right?
Not neccesarily. Home water pressure should be max 80 psi. You can check yourself by getting a gauge from the home store that attaches to your hose bib...

If you have a check valve at the incoming line whether back flow or PRV the an expansion tank at the heater is warranted.. You have a closed system. When thermal expansion occurs the built up pressure has no where to go...

Normally it would push back towards the street, but with a closed system the exp tank takes the thermal expantion.

IMO I would prefer all HWH's to have an exp tank...


And Last, am I wrong to feel that this work should be done eother at a very discounted rate or even free since they are one's that screwed up the install?
Was the water heater inspected? Permits?

Dont know where you are located but here in NJ that would fail inspection. The inspector would require a exp tank on a closed system. But I would have told you about the additional cost when installing the heater and why its needed.

Find out what the actual PSI is in the home... Only guessing unless you have a #.............
 
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Old 12-05-13, 08:06 AM
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Thanks!

I was told it was a backflow preventer when I purchased the home, the guy that turned on the water from the water company is the one that told me. We got into the convo because I was asking about using the well water for outside use. He said that the backflow preventer I have would be required, and an annual inspection as well...basically telling me that by the time I pay for the inspections etc. I may not save that much.

I thought an expansion tank was a good idea, that's why I asked about it during the install. I took his word that I wouldn't need it. I am assuming here that getting the exp. tank installed would be way cheaper than a PRV. However, I'm starting to think his prices are just high. He was great on pricing previously but I just can't how a PRV install should be $675 with a part cost at or around $100. From what I'm reading all it takes is cutting the line and soldering it in.

I will try to get the actual pressure reading for you as well. It's just odd to me that this only materialized with the new HWT, the 15 yr old 30 gal. Kenmore never had an issue...but maybe the PRV was bad on it, I don't know really i bought the house as-is on a foreclosure so there was no one to ask!
 
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Old 12-05-13, 08:19 AM
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If you post a picture of the backflow preventer we can help determine exactly what it is.

As Mike stated above, if you have either a backflow preventer or PRV at or near your meter, you need an expansion tank mounted near the water heater on the cold side. If you're a DIY kinda person, we can help you install it yourself.

You should also get a pressure gauge from your local hardware store. Get one that threads onto a hose spigot and check the pressure. It should read between 60-80psi. If you're above that, you need a PRV or your existing one needs to be adjusted or replaced. If it's between that range, all you'll need is the expansion tank.

Let us know - then we can help walk you through either installing it yourself or finding a reputable and reasonably priced plumber to help you.
 
 

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