Atwood RV Water Heater Pressure Relief Valve Replacement (2023)


Water running down the inside of your RV when it is raining is never a good thing. But water running down the outside of your RV when it isn’t raining usually isn’t a good sign either. In our case it was evidence that we had a water leak – specifically the pressure relief valve of our water heater was leaking.

I’ve replaced this type of device on residential water heaters in the past and figured it would be a straightforward repair. Of course, everything with an RV has to be just a little more challenging. Spoiler alert – mistakes were made. Fortunately, they were all captured on glorious HD video, so you can enjoy them repeatedly, in slow motion.

Note: I'm not a professional plumber or RV tech - that will be obvious in the video. Undertake these repairs at your own risk. If you are not comfortable doing it yourself, hire a professional.

Also - this is an older Atwood water heater. Other makes and models may have different specifications. Consult your units manual for information.

Seen in this video: (these are not affiliate links)

Camco 10413 1/2" Lead-Free Temperature and Pressure Relief Valve with 4" Epoxy-Coated Probe

Camco RV Water Heater Tank Rinser

QWORK 1/2" - 14 NPT Pipe Tap

RV Hot Water Heater Drain Plug with Tape, 1/2 Inch NPT Drain Plug White Plastic Drain Plug, Compatible with RV Camper and Atwood Water Heater


Hey, there it's Carson from wandering dillos in today's video, we're going to show you how to replace the pressure relief valve on your Atwood water heater.

So the first sign that we had a problem was when doing a walk around inspection of the RV.

We noticed that there was some water stains coming down from the bottom of the cabinet that holds our water heater.

So upon closer inspection, we can see that there's water dripping out of the pressure relief valve, and from the buildup of minerals on it it's obvious that it's been doing this for some time.

So the first step is we're going to turn the hot water heater off and then we're going to let the hot water run on the tap just to get all the hot water out of the system.

These water heaters, the temperatures 130 to 140 degrees.

So you don't want to be messing around with that, because you have the risk of getting scalded so we're going to remove the drain plug from the bottom of the water heater, depending on the manufacturer and the date of your unit.

This may be different.

Ours is an older Atwood.

So it has this 15 16 plastic plug that you need to remove.

If you have other styles of water heaters, it may be a metal plug, and if so it's going to have this anode rod attached to it so you're going to want ahead of time purchase a new plug that has a fresh anode rod on it, because these will deteriorate over time.

The purpose of this anode rod is to protect the inside of your water heater from corrosion so it's important to replace it when you're doing your regular maintenance using a 15 16 inch socket, we're going to remove the drain plug very carefully.

Oh, yeah, let's.

Watch that again.

What did I do wrong? Yeah, I forgot to relieve the pressure on the system.

It's still got about 60 PSI in it and I can do that just by going back in the house and leaving the hot water valve open on one of the faucets.

So fortunately, I turned the hot water heater off.

So all that water just comes shooting out of there was was cold tap water, but had I not done that it could have been 140 degree water.

And that could have given you pretty good scalding.

So key takeaway make sure you relieve the pressure before you go and open up the system while we've got the tank drained we're going to use this little wand to get in there and rinse out any sediment that may have accumulated since our last servicing.

We live full time in our RV.

So we do this about twice a year once in the spring once in the fall, if you just use yours for recreational use, probably just add it to your maintenance to do before you get everything buttoned up at the end of the season everything's coming out clear looking good.

So we'll move on for our particular water, heater it's difficult to access the pressure relief valve so we're going to go ahead and remove some of this, metallic vent shroud and give us a little more room to work with you may not have to do this for your water heater, um, they do make a special wrench that you can use to skip this step.

But yeah, it's, twenty dollars for something that you're probably only going to use once or twice I find it easier just to go ahead and remove the the sheet metal.

Once you've got a clear shot at the pressure relief valve.

And you've already removed the pressure on the system, you can just use a pipe wrench and remove the the valve from the heater just gently turning it in a counterclockwise Direction.

And here we can see that the internal mechanism is pretty much gunked up with a buildup of chemicals that have accumulated over time.

So the next step is making sure that you've got the right replacement valve Home, Depot, Lowe's.

The big box stores are probably not going to have the correct valve unless they have a section dedicated to RVS most of the ones that you're going to find there are for residential water heaters that are three quarters of an inch and almost all of the RV water heaters require a one-half inch pressure relief valve so that's, something you're going to have to look out for.

So it can be a little tricky.

You know, you go on Amazon.

You start looking it's like, hey, that one looks pretty good wrong.

That's three quarter inch, that's, not going to fit.

Oh, how about this one that one looks pretty good? Yeah, that may be half inch, but it's, too tall, it's, not going to fit in allow the door to shut on the access panel to your your water heater.

Oh, this guy.

This looks good it's short, it's, half inch, yeah, but you can't see it in this picture, but it doesn't have the probe that extends into the hot water tank.

So all three of these examples are going to be, you know, immediate returns, um, hey, this one looks pretty good too.


Got the it's stubby it's got the long probe, yeah, it's, three quarter inch, it's, not going to fit so I'll put a link in the description to the one that we ultimately arrived at.

But you can see a comparison here, it's, not exactly the same.

But it's low profile, it's half inch.

It has a long long being between three and four inch probe that sticks into the water tank.

All right.

So now we've got the right part we're going to do a little preparation before we reinstall it.

You can see here.

The threads are kind of gunked up we're going to use a 5, 16 inch tap to go ahead and kind of clean up those threads just by working the tap in and out for both the pressure relief Valves and the drain hole.

This is optional.

You do not have to do this, but I found, you know, the tap's a few dollars.

And it just kind of makes sure that everything goes together easier and minimizes the chances of leaks and cross threading with the threads cleaned up we're going to go ahead and install our new pressure relief valve.


Just going to hand tighten it at first to make sure that we don't have the threads crossed and then we'll, go ahead and tighten it down with our wrench then we're going to reinstall the drain plug again, we're going to end tighten that first to make sure it's, not cross threaded and then we're going to Snug it up with our 15 16 inch socket.

Once we've got everything tightened down.

We can go and turn the water back on.

So that we get pressure don't show this in the video, but we'll open the pressure relief valve to let all the air and get out of the tank once water starts coming out of the pressure relief valve we're going to go ahead and close that valve dry everything up let it sit for a while.

And then look for leaks.

We did have a couple small drips around the drain plug and the pressure relief valve.

So we're just going to tighten those up just a little bit more next up we're going to reinstall the little sheet metal, exhaust vent get everything tightened back up we're going to turn the hot water heater back on let the faucet run to purge any air that may have built up or Gotten Trapped in the system and then we're going to do our final inspection.

So we'll, take a close look, make sure everything's dry, no drips, new pressure relief valve dry, not leaking.

Ideally we would like it to be pointing a little down from horizontal.

So any water that does come out will just run out and not accumulate inside the the valve, but that's, how far we needed to turn it to get a tight seal and not have it.

Not have it leak if it had been any higher than that would have gone back taking it out.

Maybe put a couple more wraps, the Teflon tape and tightening back up to see if we could keep that from from going up and trapping any water.

So there you have it some tips on what to do and what not to do hope, you enjoyed the video and we'll, look for you out on the road.


Why is my relief valve leaking after changing the water heater? ›

If a recently replaced T&P relief valve starts leaking again, it probably means that the relief valve is only doing it's job; it relieving excess pressure in the water heater.

What is the pressure on the Atwood RV water heater? ›

All valves are factory set at 150 PSI and are crafted with no gaskets and epoxy-coated probes to prevent corrosion buildup.

How much water should come out of pressure relief valve? ›

The “blowdown” is usually somewhere between 2 and 20%. Once the pressure has reached the “blowdown” amount, the pressure relief valve will close again so that you can use the water heater as intended.

Why is my new pressure relief valve leaking? ›

Pressure relief and safety relief valves will leak if the valve isn't fully closed. This is a common problem in industrial settings where environments are often dusty or dirty. If there is any debris in the valve, it can obstruct the valve from fully closing, causing it to leak.

Why is my pressure relief valve leaking after replacement? ›

If you replace a TPRV and it starts leaking again, it probably means the valve is doing its job; it's relieving excess pressure.

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