TPR Valve: Odd Locations

This is now the second time I have seen these odd places for TPR Valves, and both times I wrote it up as needing correction.

However, I still believe that I am right that neither one of these is correct, because I can’t find a code that justifies either of these, as well as just plain common sense on how TPR Valves work.

The first, if I am correct, will not work because it will never sense the over pressure of the water heater, especially if the water is shut off to the water heater, and it seems to me that the over pressure would come out of the water fixtures first.

See Photo 1464 (They connected to the water supply entrance at the front of the property)

Now the second, if I am correct, will not work because it could cause greater problems by forcing hot water into the gas line, causing greater issues that I do not want to get into (Just imagine hot water shooting out of the range burners or furnace).

See Photo 1465 (Yes, that is a TPR valve connected to the flex gas supply and going back into the gas inlet on the water heater.)

Well, let me know if I am wrong, I am about to write this up to be corrected, unless I hear otherwise.

P.S. I called a local plumber that had written a note on a previous similar inspection and he said that the one from the first image was to code, but when I asked him what the code was, he said he had to look it up, and he would call me. He never called back and has not returned any of my messages. I think he thought I was dumb.

It’s a Watts 210 which shuts down the gas supply if the temp gets to high.

Installation Instructions(PDF)

Then does that supercede the need for a TPR Valve? According to the brochure, it still needs a TPR Valve.

You need to check with your local AHJ for your area.

Doesn’t your first pic who the Pressure relief for the same system?



Watts 210 valves are not recognized by the State of CA. You are in Lancaster/Palmdale, which is unincorporated Los Angeles county. Your areas follow the CBC. The homeowner or plumber is required to obtain a variance from Building and Safety to install one of these.

The City of Santa Clarita (where I live) allows these.

If/when installed properly, these are a suitable alternative for the standard TPR valve. However, they MUST be used in conjunction with a pressure-relief valve on the water supply system. There can be NO shutoff valves between the PRV and the heater. This means, the PRV should be on the outlet side of the heater, because there is usually a shutoff valve on the inlet side of the heater.