I had the PT relief valve replaced on a RUUD gas water heater, due to several drain releases throughout the day. Since then releases continue but at lesser frequency and amounts. I noticed the plumber had installed a galvanized pipe coupler/splice between the new PT valve and the gas heater nipple inside the heater. This pushed the new PT valve out by 1 1/2" from the older valve position. Is this acceptable? Since the new valve is out further due to the pipe section, could valve temperature and pressure readings by off?

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    If the release is caused by an over temp condition, that's serious. It would mean your water heater controls aren't set right or are malfunctioning. Far most likely (like Ecnerwal said) is an over-pressure condition caused by thermal expansion. Does it happen after you've used quite a bit of hot water? If so, what is happening is the cold water entering the water heater is being expanded by the heat and raising the pressure bc it has no where to go. A properly functioning expansion tank would most likely fix your problem. Your plumber should have know that. Get a better plumber. Sep 29, 2020 at 22:26
  • Don't quote me on this but I didn't think you were allowed to add any fittings between the PT valve and the tank.
    – JACK
    Sep 29, 2020 at 23:29
  • On a call yesterday with RUUD tech assistance, they confirmed no additional fittings should be added between tank and PT valve. George, to your question yes after shower, dishwasher, etc, but also have leaks in between. After additional research yesterday I replaced the "new" PT valve with another. I got one with the extension forged in with the main body. Oct 1, 2020 at 14:36
  • This newer valve is not leaking but the discharge still occurs, but not as frequent and lesser amounts than before. At this point I now have another plumber coming out tomorrow to check controls. If all else fails then an expansion tank to add or replace the heater. Probably the heater since at 16/17 years it's probably not going to last many more years. Oct 1, 2020 at 14:37

2 Answers 2


What is your water pressure? Do you have an expansion tank? Lack of a (working) expansion tank is the most common cause of overpressure releases (meaning the valve is doing what it's supposed to do, not malfunctioning.) Heated water is physically larger than unheated water, and pressure can rise due to that if no water is being used.

Extension makes no difference to pressure function, may or may not affect temperature operation (depends on probe length of the new valve, which might not have been the same as the original valve.)

  • Ecnerwal, see my comments to Jack and George. I agree the extension shouldn't matter relative to pressure, but I felt the extension may affect temp readings. I can't say what the pressure is. Never had any house issues where I needed a water pressure gauge. I'll head out shortly to Home Depot to buy one. At this point it's worth having one for possible future issues that arise. Oct 1, 2020 at 14:48
  • Thanks to all for your input! Oct 1, 2020 at 14:49

Absolutely not acceptable because the t&p relief valve has a probe that is designed for a specific depth into the tank.... never install the t&p relief valve any other way other than manufacturer install recommendations

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