It's filling up a 5 gallon bucket roughly ever 9-10 hours. It was leaking with an old valve and has been replaced, and after being replaced it didn't stop. The temperature has not been adjusted higher or lower, it's exactly where it was for the year before the leak started. Any ideas?
RET68 I think has the answer,the water heater Relief valve is a 150 lb valve,what you have is thermo expansion.It usually is noticed when a new water heater is installed,because the old water heaters relief valve was grimmy and corroded and wouldn't work anyway.some city water systems have a back flow preventer on the line where water enters the house this is a large problem contributing to the thermo expansion (when the water heats up it has nowhere to go besides out the pressure relief valve on your water heater).Private water systems don't have this problem because they have a pressure tank (well extrol) for there water.which is in essence a thermo expansion tank.
Mike, Since you haven't raised the Temperature setting on the heater which could cause this problem, you either got a bad replacement p/t valve OR maybe it was a cheepo. If that's the case, I would replace it with a good brand return the other one after you find the new on works right.
You might want to check the water pressure in your home. If it is too high, when the water is heated it expands and may exceed the pressure setting of the TP valve. You may need to lower the incoming pressure or install an expansion tank. Good Luck
Instructions : 1 Shut off the power to water heater. If electric, turn gas to pilot setting, if a gas water heater. Cut off water supply to water heater as well. 2 Drain the water from tank to just below relief valve. It is not necessary to drain the entire tank. Open a hot water faucet, drain tank from tank drain for approximately three to five minutes. 3 Prepare the new relief valve with Teflon tape. Remove the dip tube and any other connections to the relief valve. Check faucet to make sure water is not running. A slow drip is OK. 4Unscrew the relief valve counter-clockwise with a wrench to remove. Install the new relief valve. Install the dip tube with a compression fitting, if you had to cut it to remove earlier. Make all other connections. 5. Turn the water supply back on to water heater. Make sure water is running from the open faucet before turning the power back on.