Pressure Relief Valve

[Randy Reid]

I have a rheems standard water heater which the pressure release valve is releasing hot water out of the overflow pipe about once a week. I suspect that the relief valve may be going bad. Is there any adjustment to the valve or does it need to be replaced. It says on the tag that it is rated at 150 psi and 210 degrees, but the document says that it is rated at 125 degrees, so I am not sure. The heater is several years old and to my knowledge only began doing this in the past couple of months.

Thank you,MichaelDUNBAR2007-08-24 09:52:13

[Retired plbg1Participant]

You have aclosed system which might require an expansion tank, but meams you have this system for a long time, I think you need to replace the expansion relief valve.

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Art retired plbg

[SelgasParticipant]

If you don’t currently have an expansion tank fitted to your system the only safety feature you have there is the TPR valve ( temperature and pressure relief valve ).
When the water is being heated the water “expands” and the temperature increases resulting in a small amount of water being discharged out of the relief valve until the point where the pressure drops below it’s preset pressure setting and or the temperature also drops to below the preset temperature setting at which time the water flow should cease if the valve is operating correctly. If the valve continues to dribble water out of it when the water heater burner is not operating and the water temperature is at normal then you should look to replace the TPR Valve as there are no adjustments that can be made to these safety valves.

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Selgas Services Ltd
Craftsman Gasfitters, Plumbers, Electrical Service Technicians

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