Water Heater Temperature and Pressure Relief Valve Replacement

[Iowa Dave]

A recent discussion got me thinking about our Relief valve that is screwed into the top of the hot water tank and can be accessed from the outside the same as the sacrificial anode that’s screwed into the bottom of the tank almost directly below the T &P valve. I noticed a little water had dribbled out below the water heater when it made temperature the last couple times we used the 2013 21 Escape. After a little research and measuring I bought a replacement valve at my local RV dealer. He’s more expensive than the internet but the counter guy is nice and and has always been helpful and I hate to see the internet dealers take over all of the parts purchasing in this country. Got home and tried to turn the old valve out. It’s hard to get on it even with Vise Grips and there are no wrench accessible flats on these valves like I have encountered on home water heaters in the past. So a search brought me to understanding that a modified socket was available on, yup, the internet. Messaged my son in law in Indiana and 48 hours later Jeff Bezos delivered the socket to my door.

The socket fit over the valve once I flipped the relief lever out to level. It took a fair amount of torque, probably about 125 lbs but the valve came out cleanly after having been in for 10 years I had sprayed some wrench eze on the threads yesterday but it didn’t look like I got much penetration. Turned the new valve in and closed flipper and was done. Took about 5 minutes total once I had the right tool. I did not need the big breaker bar, the 1/2 ratchet was enough.

The Vise Grips would get on the valve but not squarely and I just didn’t want to experience the sinking feeling of ruining the whole water heater for the want of a $22 socket. Sure it was highway robbery but I’ll skip two fast food meals that aren’t good for me anyhow and be back to even yet this week.

Hope this helps anyone who encounters a leaky T &P valve in the future. That big socket weighs about a pound and takes a 7/8 socket on the center nut so I doubt it will be part of my Escape tool kit in the future but if you’re going to attend a rally where you know I’m going to be, let me know and I’ll bring the socket along . The job takes about 5 minutes, a lot less than it takes an old man to describe his experience.

Our heater is a Suburban SW6DE. The valve I used is a Camco 10473. The socket is available a lot of places on the internet including Amazon and ETrailer.
Iowa Dave

[rubicon327]

Originally Posted by Iowa Dave

Our heater is a Suburban SW6DE. The valve I used is a Camco 10473. The socket is available a lot of places on the internet including Amazon and ETrailer.
Iowa Dave

Dave: I know you like links so here you go. Really helps for others to quickly find parts later. I know I got one of these removed previously without the special socket but it wasn’t fun.

https://www.etrailer.com/Accessories.../CAM10473.html
https://www.etrailer.com/Accessories...xoCQ78QAvD_BwE

[Iowa Dave]

Thanks for the posting the links. I thought I could turn it out with the tools I have and maybe could have if I would have gotten more serious. However, I had this vision of destroying the threaded receiver welded into the tank and the sinking feeling that goes with a “don’t make me get rough with you” attitude that leads to disaster. So I bought the socket especially after reading the reviews. The one I bought is the one with the 7/8 inch nut welded on the end of it. I wasn’t sure I could get enough clearance for the T handle model. Hence my comment about the tool costing more than the part. It’s rare for me to buy a tool that costs more than the part but I did it this time. A while back I needed a fairly large metric impact deepwell socket. It was $14. I bought the 13 socket kit for $42, that’s more like me.
Iowa Dave

[Bill and Earline]

Well done, boss.

As usual.

Still stuck in New Orleans in August. Now the relative’s home AC not cooling. If I can’t get service first thing, I’ll be replacing the run capacitor.

[Iowa Dave]

Originally Posted by Bill and Earline

Well done, boss.

As usual.

Still stuck in New Orleans in August. Now the relative’s home AC not cooling. If I can’t get service first thing, I’ll be replacing the run capacitor.

My brother had an AC problem a few years back. I went over to “help” him. He was checking contacts with his Fluke meter and it looked totally random to me but soon he said “looks like the run capacitor.” Got a new one that did the trick and for him got him by for the season. Since then he’s changed out a bunch of things, gone solar, heat pump etc.

He came out and changed three lightbulbs for me last week. Sounds funny I know but the older LED bulbs were not making adequate contact in the fixture. They were tight but the button was a little short. He knew just what it was. Then the Belgians came out after the tomato and onion review.
Dave

[JohnK]

Thanks for sharing your experience Dave. By the way, I too like to shop for what I need in our local brick and mortars prior to getting what I need from Jeff Bezos.

With both our former Casita and our present 21C, (same water heater), those T&P valves have "leaked" once in a while but mostly do not "leak". I've always considered occasional dripping out of the T&P valve to be normal and to be as much an indication of a slightly excessively high water level in the tank as it could be an indication of possible relieving of pressure from excessively high temperature. My question for you now is are you happy with the new T&P valve and has the new valve leaked at all?
John

[rubicon327]

Originally Posted by JohnK

With both our former Casita and our present 21C, (same water heater), those T&P valves have "leaked" once in a while but mostly do not "leak". I've always considered occasional dripping out of the T&P valve to be normal and to be as much an indication of a slightly excessively high water level in the tank as it could be an indication of possible relieving of pressure from excessively high temperature.

Some weeping during warm-up is normal due to the expansion of the water. Especially if someone has a check valve on the incoming cold water line. The Suburban manual has some verbiage about it.

[C&G in FL]

I do not open the pressure release valve when filling the water heater. I open the hot water tap until the faucet stops “spitting.” As a result, I probably have a small airspace at the top of the tank. I have operated the valve before every summer when the tank is empty. My pressure relief valve has never leaked or dribbled since I’ve owned my trailer.

[Iowa Dave]

Originally Posted by JohnK

Thanks for sharing your experience Dave. By the way, I too like to shop for what I need in our local brick and mortars prior to getting what I need from Jeff Bezos.

With both our former Casita and our present 21C, (same water heater), those T&P valves have "leaked" once in a while but mostly do not "leak". I've always considered occasional dripping out of the T&P valve to be normal and to be as much an indication of a slightly excessively high water level in the tank as it could be an indication of possible relieving of pressure from excessively high temperature. My question for you now is are you happy with the new T&P valve and has the new valve leaked at all?
John

Going out camping tomorrow . Haven’t tried the water heater since the install.
We’re only going about 25 miles and have a nice shower building where we’re going so don’t really have to have hot water. I’ll report when I get back. We are taking two grandkids 4 and 6
So when I posted last week how doable that is I’m putting my patience and child rearing abilities where my mouth is.

I’ve always had considerable scale when I’ve drained the water heater via the anode and
though I’ve only flipped the lever a few times over the years I think I probably had something that stuck to the face on the valve. I just didn’t like the dripping and thought why not?
Iowa Dave

[John in Santa Cruz]

Originally Posted by C&G in FL

I do not open the pressure release valve when filling the water heater. I open the hot water tap until the faucet stops “spitting.” As a result, I probably have a small airspace at the top of the tank. I have operated the valve before every summer when the tank is empty. My pressure relief valve has never leaked or dribbled since I’ve owned my trailer.

yeah, me too. I've opened the pressure release valve a few times, but not regularlly.

[CharlesinGA]

Both Suburban and Atwood/Dometic water heaters have a procedure in the owners manual on setting the air gap inside the tank. This needs to be reset every month or so when in use.

WATER WEEPING OR DRIPPING
FROM PRESSURE RELIEF VALVE
You may experience water weeping or dripping from your water heater’s Pressure and
Temperature (P & T) Relief Valve when your water heater is operating. Water weeping
or dripping from the P & T Valve does not always mean the P & T Valve is defective.
As water is heated, it expands. The water system in a recreational vehicle is a closed
system and does not allow for the expansion of heated water. When the pressure of
the water system exceeds the relieving point of the P & T Valve, the valve will relieve
the excess pressure.
Suburban recommends that a check valve not be installed directly at the inlet to the
water heater tank. This will increase weeping of the pressure relief valve.

One way to reduce the frequency of this occurrence is to maintain an air pocket at the
top of the water heater tank. This air pocket will form in the tank by design. However, it
will be reduced over time by the everyday use of your water heater.
To replenish this air pocket:
1. Turn off water heater.
2. Turn off cold water supply line.
3. Open a faucet in the RV.
4. Pull out on the handle of the Pressure Relief (P & T) Valve and allow water to flow
from the valve until it stops.
5. Release handle on P & T Valve - it should snap closed.
6. Close faucet and turn on cold water supply; as the tank fills, the air pocket will
develop.
Repeat this procedure as often as needed to reduce the frequency of the weeping of
the P & T Valve. If the weeping persists after following this procedure, you may elect
to install an expansion or accumulator tank in the cold water line between the tank and
check valve to relieve the pressure caused by thermal expansion. Contact your local
dealer for assistance.

Charles

[Bill and Earline]

I had to read up on this expanding water.

It turns out it does expand about 2% when heated to water heater temps.

Interesting. I hadn't been aware of that.

Amazingly it also contracts about 2% when it cools back down.

Maybe that's why I haven't needed to go through the procedure to maintain the air pocket.

Maybe I'll go check my anode, just to have something trailery to do.

[Ron in BC]

Originally Posted by Bill and Earline

Maybe that's why I haven't needed to go through the procedure to maintain the air pocket.

Me neither, drain in Winter, fill in Spring until water comes out the hot water tap.

Never ever done anything different.

Ron

[John in Santa Cruz]

Originally Posted by Bill and Earline

I had to read up on this expanding water.

It turns out it does expand about 2% when heated to water heater temps.

Interesting. I hadn't been aware of that.

Amazingly it also contracts about 2% when it cools back down.

Maybe that's why I haven't needed to go through the procedure to maintain the air pocket.

Maybe I'll go check my anode, just to have something trailery to do.

also, heated water outgasses any dissolved air... thats why it sometimes looks cloudy coming out of a household tap, but the cloudiness floats to the top and goes away, its really tiny bubbles.

[HABBERDABBER]

Originally Posted by Bill and Earline

I had to read up on this expanding water.

It turns out it does expand about 2% when heated to water heater temps.

Interesting. I hadn't been aware of that.

Amazingly it also contracts about 2% when it cools back down.

\.

Plastic materials can expand up to 13 TIMES more (or less in cold) than steel with temperature fluctuations. Stuff moves. Temperature matters. Sometimes, a lot.
Think back to the Space Shuttle that blew up because of shrunken, cold O-rings that leaked, due to the cold launch conditions.
Kaput!, A couple of billions of dollars worth of spacecraft and effort.

[Iowa Dave]

Boyles law, Charles law, Lavoisier, all them guys had all kinds of stuff figured out. I had an absolutely fine physics teacher in high school. He was one of my all time favorites. Course that was pretty close to 6 decades ago. Don’t remember those formulas now. I replaced the valve, filled the tank, bled some water off getting the air out of the lines. Fired up the water heater on electric. Working perfectly. No runs, no drips no errors. Also replaced the fresh water tank drain valve as the flipper had broken off late last year. Still had enough to turn it but thought I ought to get back to fully functional.

Camped tonight on the Coralville Reservoir, a COE facility on the Iowa River. About15 percent occupancy. We have electric only but the water is only about 40 feet off the back of the Escape. $20 per night for the younger folk with all the money and the ginormous fifth wheels. Ten bucks for us with the geezer pass. Made little pizzas in the toaster oven wirh Graziano Brothers pepperoni for dinner. Magnifico.
A two day shake down in preparation for a trip to southern Wyoming and the Snowy Range shortly.
Looking for that Wyoming cowgirl on her horse, pacing the Jordan motorcar, “somewhere west of Laramie”
Iowa Dave

[CharlesinGA]

The air pocket disappears because the air absorbs into the water. This is a problem with well tanks (non bladder) and that type of tank has an air control to maintain a head of air on the tank.

Charles

[Ron in BC]

Originally Posted by CharlesinGA

The air pocket disappears because the air absorbs into the water. This is a problem with well tanks (non bladder) and that type of tank has an air control to maintain a head of air on the tank.

Charles

So maybe those of us who have installed accumulator tanks are getting a second benefit from them. Allowing expansion without tripping the TPR valve.

Ron

[alanmalk]

Originally Posted by Ron in BC

So maybe those of us who have installed accumulator tanks are getting a second benefit from them. Allowing expansion without tripping the TPR valve.

Ron

Perhaps there is something to that theory. I have had an accumulator since day one - and never had a drip from the TPR valve.


Anyone else...?

[SWCO]

Originally Posted by alanmalk

Perhaps there is something to that theory. I have had an accumulator since day one - and never had a drip from the TPR valve.


Anyone else...?

https://www.escapeforum.org/forums/f...nks-16104.html See post #13 as well as link in that post.

I installed a 2 gallon accumulator and moved the ETI installed check valve (explained in link). Before the valve was relocated from the inlet side of the water heater the accumulator could not mitigate hot water expansion.