Roger Dowdy
Member
Misery loves company. My daughter's relief valve does the same thing. May go weeks without a problem them it leaks couple of cups into a bucket. It seems to happen when they are out of town on business for a couple of days and little hot water is being used. I suspected the two gallon expansion tank which had only 15 lbs of pressure in it. I relieved all pressure from the hot water tank before testing it. Aired the new expansion tank to 55 lbs pressure while still on the tail gate of my truck to almost match 60 pounds of cold water pressure. I installed the same pressure gauge in the picture above and we are monitoring pressure at the drain spigot at the bottom of the tank. This week we were at their house for three days. When I walked into their garage where the water tank is located I found current and high pressure to be 150 lbs and about two cups of water in the bucket. Immediately went into the house, turned on a hot water faucet, went back to the garage and the black needle was back at it's normal 60 lbs.
My guess ( I'm not a plumber) is that her pressure regulator is seeping pressure as macgyver indicated. My daughter's expansion tank is a 2 gallon tank and her water heater is a 70 gallon tank. I think that's too small but I replaced it with a two gallon because that's what had previously been on the tank and because of it's physical mounting I was concerned about weight. This week I have reduced her water temperature by two notches ( darn thing is labeled "low" middle notch, then A, B, C and then hottest ( I've set it to the middle mark on the knob...it was on "B" ....don't know the corresponding temperatures) then I reduced regulator pressure by 5 pounds and asked my daughter to monitor. For three days now cold water pressure is 55 pounds and the red needle shows highest reading to have been 70 pounds. We'll monitor for a couple of weeks then increase temperature back up a notch and see what happens.
At least with the gauge on your water heater you can tell if the relief valve is operating properly. If my daughters problem returns after moving the temperature knob up to "A" I'm just going to replace the pressure regulator and maybe even the expansion tank with a larger tank. I don't know her current water actual temperature but they say it's acceptable for now. They live 55 miles from us so I'm not there every day.
Roger
My guess ( I'm not a plumber) is that her pressure regulator is seeping pressure as macgyver indicated. My daughter's expansion tank is a 2 gallon tank and her water heater is a 70 gallon tank. I think that's too small but I replaced it with a two gallon because that's what had previously been on the tank and because of it's physical mounting I was concerned about weight. This week I have reduced her water temperature by two notches ( darn thing is labeled "low" middle notch, then A, B, C and then hottest ( I've set it to the middle mark on the knob...it was on "B" ....don't know the corresponding temperatures) then I reduced regulator pressure by 5 pounds and asked my daughter to monitor. For three days now cold water pressure is 55 pounds and the red needle shows highest reading to have been 70 pounds. We'll monitor for a couple of weeks then increase temperature back up a notch and see what happens.
At least with the gauge on your water heater you can tell if the relief valve is operating properly. If my daughters problem returns after moving the temperature knob up to "A" I'm just going to replace the pressure regulator and maybe even the expansion tank with a larger tank. I don't know her current water actual temperature but they say it's acceptable for now. They live 55 miles from us so I'm not there every day.
Roger
