TPR tapped into cold

Has anyone seen this set up before?

Picture 002 (Small).jpg


Thankfully- NO
What in the world is the cold water loop for?

Good question…two water heaters set up the same way. I can’t figure out the installation logic.

The logic was faulty - recommend repairs by a licensed plumbing contractor…

Looks like M.C. Escher did some plumbing too.


Thats an extreme recycling program

WAtts pressure relief valve. It takes the place of an expansion tank. It is installed correctly.

See this LINK

Oh, that was a margarita ASNR. :cool:

I think Michael’s got it right.

Wouldn’t been easier and better to install a pressure regulator at the outside shutoff valve? The water heaters are protected, but the rest of the plumbing is see the higher pressure in the line.

The whole system is protected. The hot and cold side are not isolated from each other. They meet in the water heater tank.

The installation instruction on the watts valve above does not show this configuration…or at least maybe I missed it.
Any how the question I have is how would this work?
We can not see from the picture where the TPR drain line goes to, but if it is tee’d into a supply line, then there is nothing to keep the water from flowing out of the drain line. Obviously I am missing something.

I think I understand what you mean. I don’t argue this is a pressure only relief, but I wonder if its installation is correct. Meaning, whey do both the tpr and the pr both connect to the same tail? Is this OK?


That is allowed, and common in this jurisdiction. The expansion valve takes the place of the expansion tank and drains into the overflow pipe from the TPR valve.

Until the AHJ writes it up here as a faulty install, I won’t call it out.

Looks closest to the model 3L which is for Gas water heaters with a seperate gas shutoff to protect from overtemps.(not an exact match)

Looks like a standard TPV valve plumbed back into the cold side. I can’t see the tail below the upward 90 but I’ve never seen this configuration.

Still would defer it…

So the valve on the tank that looks like an ordinary TPR is an ordinary TPR, and the thingus that looks like a T-fitting on the cold line (upper right) is a watts valve?

Bingo…that is correct. I had to look at the picture again. At the top I thought that was a copper fitting…but it is the watts valve that was referred to. Now I understand the configuration, and as far as I know that is acceptable. I would not call that.

Ahh, so the thing in the circle is the watts valve… more better now :roll:

Watts valve !.JPG

Been busy today but you got it Mike.
There is no test lever on the watts device. The top of the fitting is where the spring and valve are (it is not open to air).
When the pressue gets to the devices set point the spring compresses and the valve opens reliving the excess pressure into the TPR drain line.
I hope that’s clear fellas.

interesting setup. if the watts valve fails do you run the risk of your tank running low and burning up elements