Replace a Hot Water Tank Relief Valve

 Today we're going to replace a TNP or pressure relief valve to a hot water tank. They come in different pressures and different sizes. If you don't know what you need on the label here, usually it will tell you your BTU max and your pressure, uh, your rated pressure on it. First thing you're going to do is shut the water supply to the tank off.

Uh, sometimes it will be a valve like this. Other times it will be a ball valve like this with a handle. Uh, sometimes it will be a gate valve that looks kind of like a wagon wheel and it's, it'll always be near your, uh, water meter, uh, supply. So my water meter is here, so I will be turning that ball valve off.

And that way is off just like that. Next, you're going to want to drain the water. So you can either pull this handle like this and that will drain some of the water or, or you can attach a hose to the bottom of the tank and either drain it into a bucket or out to a drain. Am I cracking it open

and you drain the water into a bucket. Also, while it drains, try not to touch these and open the pressure if you don't have to, because sometimes they will get stuck and if you have a situation where the drain is clogged or something like that, which goes in usually into a drain, it could get stuck open and you'll have continuous water that you won't be able to stop.

But we are changing it, so it doesn't matter. Next, usually the pressure relief leaf valve will have some sort of pipe that comes down into a drain or such, um, that you'll either need to cut or if it has a shark bite, these are releasable. You could take them off. Or in some cases it will be soldered into place like this over here, which you will need to either cut or sweat off, which involves a torch.

In my case, I was able to use the shark bite fitting with this tool here and channel locks and able to get it separated from the pipe, and you could use your channel locks and simply loosen the pipe. Then you use your pipe wrench or equivalent, put it on the pressure relief valve. Sometimes you might need leverage, but in this case it was fairly loose.

And you just remove it. Once you remove it, it comes out. You'll probably get a little bit of water. So have a bucket handy.

Apply Teflon tape or paste or some sort of thread compound to the threads going in the direction that you will be screwing it in. Don't go the opposite way 'cause you want the Teflon tape to go. Um, wrap around with the threads. And go ahead

and swap out your pressure relief valve

like so to snug it up so it is straight and align with the pipe. Then screw your drain pipe.

Back into your pressure relief valve

and tighten,

and then if you cut your pipe, you will have to re solder it back together. But in my case, I

used a push to connect fitting

and you just pushed that up. Like, so then go ahead and slowly turn your water back on. Never open it wide open. Slowly open it, open it. Once there's no more flow and the tank is full, you can go ahead and open it fully and check for leaks. Don't forget to bleed any air that is now in the system. Open up the faucet, hot and cold, and bleed the air, and that is how you change a pressure relief valve.