[rfrankmcm]

Hot Water Heater: T&P Valve Drain Connected to Cold Water Intake
AO Smith Model ECS50-210

I am a new home owner, trying to learn about the appliances in my home, and their basic ins-and-outs. I know why the T&P Valve is connected, and how it works, generally speaking, but there is a bypass on the cold-water in-take that connects to the drainage pipe, stemming from the T&P Valve outlet.

Why would this connection be made? Is it a redundancy solution for pressure relief in case of a build-up?

Furthermore, the connection bypasses the cold-water intake cutoff valve. If the valve is closed for the purposes of maintenance on the water heater, would this divert the cold-water flow to the drain? And wouldn't that mean I would be required to close the water supply off closer to the main source to stop a continuous flow through the drain?

I'll provide more information upon request.
Any (accurate) feedback is appreciated. Thank you.

 

[TheEplumber]

The pipe from the T&P is an indirect waste line. So the other line should be an indirect line as well. Can you upload a picture of the line and it's connection at the CW supply- or at least describe it?

BTW- welcome to DIY Chatroom!

 

[rfrankmcm]

Thanks for the quick response!

The cold-water line goes from the wall to the tank. In-between that there is a cutoff valve for the cold-water. Between the wall and cutoff valve is a pipe that goes up vertically, and then through a set of elbows drops down toward the tank, and intersects with the T&P indirect waste line (as you pointed out).

I am not sure if that description is accurate enough for our purposes (I am still learning how to attach an image via URL). If you need a better description, I will provide it as best that I can. Meanwhile, I'll see if I can figure out how to attach my file image.

 

[chandler48]

I've never seen this set up, but it appears the installer is using an over pressure valve as an expansion tank substitute. If the pressure is too high on the tank after heating the water, the valve will open and evacuate the excess. Others may have different views on it, but IMO an expansion tank should be installed at the water inlet, all the piping removed and capped down to the lateral evacuation line to allow the T&P to operate independent of the expansion valve. Let the others comment as well.

 

[clarenceboddick]

That's not to current FL code. New code requires a pan in habitable space with the pan draining to outside. The T&P has to be drained directly into the pan.

 

[Yodaman]

Also concerning, the cathodic rod appears to have been removed. The tank will be short lived if so.

 

[chandler48]

Clarenceboddick, question. IF the T&P valve exits the building as it appears to and is within 6" of the ground on the outside, why would it violate code? I would prefer it evacuating to the atmosphere than into a pan where there may or may not be a means of it draining successfully. Just curious.

 

[TheEplumber]

rotated image-

That appears to be a pressure relief valve. You will need to turn off the main to service it but that is preferred. Pressure valves should not have isolating valves.

Why someone would install this is beyond me... I suppose, as mentioned, it's an alternate method instead of an expansion tank.

As for the relief line discussion. In my state, both must pipe separate to an approved location such as floor drain, exterior (between 6-24") above grade or to the garage floor. T&P may not drain to the pan here.

 

[rfrankmcm]

Thank you all, for the responses.

I will have to locate the main for future reference, but I'm interested in learning more about the topic. Can anyone provide any links for codes in my area? I know how to google "FL Building Codes", but does anyone have any references that are more "professional" so to speak.

Again, thank you.

 

[BayouRunner]

Years ago every once in a while you would see a relief in the line like that but no relief valve that came with the tank. My guess is someone changed the hot water heater and just left the old valve the way it was and tied in the new relief vale with the same line. They didn't go off with temperature, only pressure so it didn't matter if it was on the hot or cold side