Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Installed a new pressure release valve on electric water heater because old valve was dripping water on floor. New valve also dripping water. Any ideas? Suggestions? Water temp set at 110F, so it's not because of excess heat. Water pressure regulator on incoming water main set at 50 lbs. I'm out of ideas as to what could cause valve to seep water.

share|improve this question
Have you tested your home water pressure, especially when other faucets are closed and the hot water heater is heating? Do you have an expansion tank? – BMitch Mar 21 '12 at 17:56
Have you measured the water temp at the tap?It is possible that the thermostat is bad allowing pressure to build and the safety to vent.Any big changes in the electric bill? Is the replacement part rated the same as the orignal? – mikes Mar 27 '12 at 2:37

Did you test the valve after you installed it? If so you'll need to replace it again. The moment you test the valve you allow calcium and dirty water that can again make the valve lose its seal and continue to leak. They are very temperamental!

share|improve this answer
This is not true. Relief valves are meant to be tested at least yearly. – Andrew Kozak Oct 6 '15 at 1:06

TPR valves open on high temperature or pressure. Check the pressure by hooking a gauge onto a garden faucet, run the hot water until the heater turns on, and then close all other fixtures except the garden faucet. Check the pressure at the start and again when the water heater finishes it's cycle. If you see a significant climb in pressure, you need an expansion tank, or your existing expansion tank is failing. If your pressure is always high, you need a pressure reducing valve. The target pressure should be 45-60psi.

If the water pressure is not high, then verify the water temperature. Using a cooking thermometer in a cup of hot water should work. An IR thermometer on the hot pipe after water has been running for a bit may also work. The target temperature should be 120-140F, or 130-140F if you have a dishwasher.

If neither the temperature nor the pressure are high, then your valve has failed or is defective and you should replace it. While it's possible to get some dirt in a valve after testing it, it's still a good idea to periodically test it and be sure it works. A valve that fails closed is dangerous while a valve that leaks is annoying. You may want to flush any sediment from the tank before testing it to minimize the risk of a stuck valve.

Here is some of the equipment mentioned.

Pressure gauge:

enter image description here

Expansion tank:

enter image description here

Pressure reducing valve:

enter image description here

IR Thermometer:

enter image description here

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.