No Hot Water!

[Kamper Dave]

No Hot Water!
Mid-morning and out of the blue there was no hot water from any faucet in the RV. I opened the water heater pressure relief valve to learn that water was being supplied to the heater.
I regretted not flushing the mineral deposits from the water heater for the past 5 months. I figured the deposits had built up and clogged the heater output. I turned off the water heater and opened the low point drain to depressurize the system, once the heater drain plug was removed I flushed the deposits from the heater using a ¼” OD Teflon tube under full camp ground pressure. There were not an unusual amount of deposits. So, I bit the bullet and removed the brass check valve from the water heater output to find it in pieces.
I spent $14.00 for a cheap grey plastic check valve from the only RV place in town and screwed it into place. We re-pressurized the water system and turned the water heater on. So far, so good.
I think this check valve is just for winterizing and I am tempted to replace it with a manual shut-off valve.

[Stan]

Can I assumed from your writeup that there was actually hot water in the tank but not getting to the faucets?? Interesting issue. I will have to keep this in mind.

[Kamper Dave]

Originally Posted by Stan

Can I assumed from your writeup that there was actually hot water in the tank but not getting to the faucets?? Interesting issue. I will have to keep this in mind.

Yes. You may assume that there was water in the tank.
I proved this to myself when slowly releasing the pressure relief valve.
Be careful releasing the relief valve can scald you at the least you will get wet.

[Stan]

I drain the H/W heater after each trip. Haven't had an issue like that yet. Maybe i should get a check valve and either replace it or have it in the toolbox "just in case". My rig is 8 + years old and am kind of waiting for a few of these type issues to crop up. Currently on a trip to the SoCal deserts and everything is fine....knock on wood.

[Kamper Dave]

Originally Posted by Stan

I drain the H/W heater after each trip. Haven't had an issue like that yet. Maybe i should get a check valve and either replace it or have it in the toolbox "just in case". My rig is 8 + years old and am kind of waiting for a few of these type issues to crop up. Currently on a trip to the SoCal deserts and everything is fine....knock on wood.

I replaced the original check valve last year because it didn't function while winterizing. So the new brass check valve lasted less than a year.

This is why I'd like to replace it with a manual valve for winterizing. The only danger would be activating the hot water heater with the intake and output isolated; surely the high pressure relief valve would safe the day. I hope.

[harley]

My old camper had 3 shut off valves for the water heater, no check valve...worked great. they were either ALL in the vertical position or ALL in the horizontal position , ,depending on winterizing or regular use..(cannot remember which at the moment)
Pretty idiot proof..

[NorskeNY]

I think our heaters are built like this - is the one marked check valve the one you replaced? What thread size is it - 1/2 or 3/4 inch?

[Kamper Dave]

Originally Posted by NorskeNY

I think our heaters are built like this - is the one marked check valve the one you replaced? What thread size is it - 1/2 or 3/4 inch?

Norske,
Yes. That is the check valve in question.
Do you see any reason for not replacing it with a gate valve?
I still have the old brass check valve and have already gutted it. I would remove the new cheap plastic check valve and use the old brass unit as a nipple; then cut the red output pipe and slip in a gate valve.
What do you think?
Thanx in advance.................. Kamper Dave

[NorskeNY]

What I found - probably best to keep one installed:

The RV Doctor: RV Water Heater Check Valve - What For?

It’s there to prevent hot water from migrating back into the cold water system. If a branch cold line, say to the toilet, is plumbed (tee’d) into the cold line too close to the back of the water heater, it could siphon hot water out of the tank and into the toilet when it is flushed. It’s happened before! As long as you have no branch cold lines tee’s near the inlet to the water heater, you shouldn’t experience that problem. Having a check valve at the cold inlet to the heater also prevents mineral deposits and residue from backing into the cold system from inside the water heater. As long as you flush the water heater out once or twice a year, this too, shouldn’t be a problem.

[Russb]

I believe the check valve in the hot water outlet line is to prevent antifreeze from going into the water heater when winterizing. The article is about the check valve in the cold water inlet line.

[Dayle1]

Originally Posted by Russb

I believe the check valve in the hot water outlet line is to prevent antifreeze from going into the water heater when winterizing. The article is about the check valve in the cold water inlet line.

X2 A check valve in the hot (outlet) side would only prevent water already in the red lines from flowing back into the tank. But lacking a gate valve, it is part of the bypass system. As the article states, a check valve in the cold (inlet) side is needed to prevent hot water from back flowing thru the cold lines when a cold tap is opened.

[Kamper Dave]

Thanks for your replies!

A new Brass Check Valve is on order as well as an in-line shut off for when and if it malfunctions before a winterization.
Now all I need is longer arms to reach the water heater!
Kamper Dave