Bradford White water heater leaking after 3 months?

[SocialDx]

I recently purchased a Bradford-White water heater and had it installed professionally last June. I've been noticing water at the bottom of the water heater near the drain in the floor. At first I thought it was coming from the tube that drains condensation from the furnace since that has happened before. But then I came to my senses and realized the A/C hasn't been on in weeks. Did I just get a defective unit or could something be wrong in the installation? It's a small leak that comes from underneath the tank. Also, how much of a PITA is it going to be to get it replaced and I'm going to have to shell out any more money? I will have to look for the receipt as I'm not sure where it would be. Your help is greatly appreciated.

[jadnashua]

First, put a bucket underneath the discharge pipe of the T&P valve to determine if the water is coming from there. If it is, then go to one of the big box stores or a plumbing or hardware store and pick up a water pressure gauge with a tattle tale hand (to show peak pressure) and put it on someplace where it will fit (WM supply, hose bib, drain of the WH, etc.). Leave it overnight, or longer if possible. See what the pressure is 'normally', and what the peak reading is while hooked up. If it exceeds 150# (give or take a little), that's why the safety valve is opening.

If you have a closed system (either a check valve or a pressure reduction valve), expansion of the water in the WH will raise the pressure enough to cause this safety valve to open and dump a little water. The pressure gauge will show you this. If you have a PRV and DON'T have an expansion tank, you need to have one installed. If you DO have an expansion tank and a PRV, the PRV OR the expansion tank may be bad, allowing the pressure to rise enough to trip the safety valve. A new tank, especially if it is larger than the old, will be more efficient and may have more water that can expand when heated, and it may show the problem where it wasn't exhibited previously.

If it is leaking from the tank and not the T&P valve, the plumber is likely to cover it since many have a 1-year warranty, and the tank has a longer one.

[Gary Swart]

jadnashua has diagnosed your problem quite well. The "leak" is not a leak, it is the T/P valve operating properly. Heated water expands and with no place to go because of a check valve in the system, the pressure rises high enough to open the T/P and relieve the excess pressure. When the pressure is relieved, the valve closes and ever thing appears normal until the heater begins to heat again. Not a difficult fix, but do as suggested and get a pressure gauge and test your pressure. This topic has been discussed numerous times in the past, so you can go through the archives and read up on the problem and the solution.

[SocialDx]

Thanks for the help. I put a bucket under the tube connected to the prv and sure enough there was water in it tonight. I guess the next step is a trip to the plumbing supply store to test the water pressure. My concern with installing an expansion tank is that the water heater is in a tight spot between the furnace and a laundry tub. Do they make ones that are pretty compact? I will post pictures of the spot tomorrow. And are these pretty easy to install?

[Gary Swart]

The expansion tank can go anywhere in the cold water supply between the pressure regulator valve and the water heater. They are not difficult to install, but they do have to be well supported. The box the Watts tanks come in has illustrations on several ways to do this.

[jadnashua]

That safety valve is a T&P valve (Temperature and Pressure). A PRV (pressure reduction valve) may be in your house, or you may have a check valve in your incoming water supply, which, if either or both of those are present, would make your supply system 'closed'. Closed systems need somewhere for water to expand when heated. For all general purposes, water doesn't compress, so when heated, it instantly starts to increase the pressure, expanding pipes and hoses like balloons (at a micro level, but measurable). Once the pressure reaches 150#, that safety valve is designed to open to prevent you from splitting the seams on the WH. Even pressure excursions from 'normal' to 150# puts stresses on things, and it should be addressed to minimize damages and extend the life of things.

The other possibility is that that T&P valve is bad or there's some debris caught underneath the seal. Not common on a new one, but not unheard of. After you've checked the pressure, you'll know. Since it doesn't discharge all the time, it's probably fine. Leave the gauge attached for at least overnight, and 24-hours or more is best. Often, the pressure rises overnight as people stop using water and the utility pumps water to the storage tanks. Then, in the morning, after everyone starts taking showers and the WH runs, you get the maximum effect of the expansion as the mostly cool/cold water needs to get reheated.