After two days of observation of our water pressure (using a test gauge), the normal water pressure is typically between 61 and 63 PSI, with 62 being the most common reading. Peak-pressure readings have hit 82 PSI several times. I read that, according to plumbing codes, 80 PSI of pressure is the maximum for hot water heaters and anything above 80 psi can be bad for them.

I have not noticed any of the problems that are said to be associated with water pressure that is too high.

  • I have a boost pump installed that is a fairly common one. It pressurizes to 100psi. Your equipment should list maximum pressures. Are your pipes in good shape? Do you have a pressure tank or water hammer issues? – Matthew Jun 27 '20 at 2:41
  • This is for a new hot water tank that we haven't purchased yet. The documentation online says to check the label on the tank. So we don't know the maximum pressure yet. The pipes seem to be in good shape. We don't have a pressure tank. We notice very slight water hammer occasionally. – BigBlonde Jun 27 '20 at 12:42
  • Do you have an expansion tank on your existing system? Also most water systems have check valves to prevent back flow. One situation I've personally seen occur, is after the use of a lot of hot water, when the cold water that entered the water heater got heated up and expanded, it raised the pressure enough in the house that the PRV starting doing it's thing discharging water at about 100 PSI. Adding a expansion tank cured the problem. – George Anderson Jun 27 '20 at 14:47
  • Where did you hear this business of 80psi max for water heaters? If that were true, they would have an 80psi relief valve, but guess what? They have a 150psi relief valve... – Jimmy Fix-it Jun 27 '20 at 14:58
  • I have never seen a water heater that had a max pressure that low. What brand and model? The name plate should state the max pressure, fluctuations can affect the operation if the fluctuations happen while in use. – Ed Beal Jun 27 '20 at 15:50

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.