The Tank › Electric Water Heater TPR valve
- May 11, 2009 at 11:28 am #11359
I have a standard 40 gallon Whirlpool electric water heater. It has an indicator light that serves as a diagnostic tool. The indicator flashes (5) display the lower element is out. I have proven there is nothing wrong with the elements. I turned the power off to see if lowering the temperature (thinking also reduction in pressure) assuming the relief valve would close … no such luck. I lowered my pressure at the main … still no help. I installed it only 6 months ago! This is the first problem I’ve had with it but I had similar problems with previous tanks. I realize that it’s a pretty safe guess that the TPR valve needs to be replaced (usually after a few years use) … I want to know why this problem has occured and what can be done to prevent TPR failure in the future. I would appreciate it if anyone could throw some ideas at me regarding this issue.May 11, 2009 at 12:01 pm #11360Randy SchuylerKeymaster
There’s really nothing you can do to prevent a T&P from failing. They work for some period of time and then don’t, usually because they get clogged with mineral deposits.
But if you replace it and it still does the same thing, then you should go to the homepage, click on Troubleshooting, then Tanklets, then Temperature/Pressure Relief Valves and perform the test for thermal expansion.
Randy SchuylerMay 11, 2009 at 4:45 pm #11361
Thanks for the info! I believe I may know what is causing the TPR failures … I was told that the previous owner may have removed a secondary regulator near the house off the main. Logically I would assume that if water is coming directly from the main to the tank than obviously it’s going to build a lot of pressure. Does this sound like a reasonable assumption? There is absolutely no rust or calcium build up either by the way. If I put a secondary regulator in, do you thik it will solve my troubles?May 11, 2009 at 9:25 pm #11362EjParticipant
How did you prove there was no problem with the element? Also have you checked the water pressure with a gauge at the heater both during and after a heating cycle? We really need to know the true facts because guessing gets expensive.May 12, 2009 at 1:18 pm #11363
I checked the elements using a multimeter and then removed and physically inspected them. I had new replacement elements for it … so I replaced them anyway since I had gone that far. I have not checked pressures during heating cycles. The relief valve remains open even when the power has been turned off for 12hrs. I’m not sure what to do at this point. I know guessing can make things expensive but I may have to do just that. There are no check valves or anything coming into the tank … just 2 PVC lines coming from the wall. It is certainly not up to code. Thanks for all the help. Any additional advise would be greatly appreciated. I think I will replace the TPR and see if that does’nt fix it … if only for the moment. I’m losing a gallon a minute!May 12, 2009 at 8:54 pm #11370Randy SchuylerKeymaster
Then replace it, but do get a water pressure gauge and test both static pressure and for thermal expansion.
Randy SchuylerMay 12, 2009 at 10:47 pm #11371EjParticipant
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