Atwood Water Heater Failed

[More-Gas]

Our Atwood water heater quit putting out water today. The water fills with water heats up fine on electric and propane but will not let the hot water get to the faucets.
I checked bypass valves to make sure they are in the correct position,
Under the motorhome right below the water heater there is a inspection plate when I took it off I can see the water inlet & outlet hoses but cannot reach them from there.
The question I have is there check valves on the inlet and outlet lines?
If so do you think the ck valve on the outlet line failed?
If that might be the problem I think I need to remove the water heater to get to the back side and replace.
Any suggestions would be a great help.

[BFlinn181]

With the water pump or city water on, turn the heater off and let it cool a bit so you don't get burned. Then pull open the pressure relief valve tab. If water flows out under pressure, you know it's flowing into the tank. Then you'll need to determine if it can flow out the outlet line. If you can't access the fittings on the back of the tank, you could try pouring a few gallons of vinegar into the water heater and let it soak for half a day or so. If it's deposits in the check valve, the vinegar should dissolve them.

[Old-Biscuit]

Check valve on HOT out (top fitting screwed into tank)

They are a cheap plastic plunger/spring/o-ring inside either a plastic nipple or brass nipple.
They clog up, they fall apart, they jam, o-ring dislodges etc.

Repair/fix...........REPLACEMENT!



RV Mfgs install check valves..cheap, easy and can be done before installing water heater.


I hate them......more trouble then they are worth.
I prefer 3 valve system.....one on cold inlet (bottom line), hot outlet (top line) and bypass (line between cold/hot)
Sometimes it worth the trouble to install the valves even if it requires ALL new plumbing lines to a remote area where one can access them

[More-Gas]

Thanks folks I will try the white vinegar trick as the valve is very hard to reach, I will keep you posted.

[More-Gas]

This may sound like a dumb question but here goes, I watched a youtube vid and they said to try white vinegar in the tank heat and let set overnight
(someone suggested it here also) this may clear debris from the hot outlet check valve.
How I know how to drain the tank but how do you fill the tank with straight vinegar?
Thanks for all the help.

[BFlinn181]

If you have a winterizing connection at your water pump that's used to draw RV antifreeze into the water system, you could use it to draw in vinegar instead. Use about a 50:50 mix of vinegar, i.e. if the tank is 6 gallons, use 3 gallons of white vinegar.

If you don't have the winterizing connection at the water pump, you could use a funnel and your water hose hooked to the city water connection. Pour the vinegar into the hose, when the hose is full, turn on the pump, repeat until all is drawn into the water heater.

Another method is to use plumbing fittings to hook a hose up to the pressure relief valve at the water heater and get the vinegar in that way.

https://www.youtube.com/watch?v=IKg0R9oiMP0

[powercat_ras]

You should be able to get to the check valve the same way you get to the winterization bypass valve. As stated, you might want to remove the check valve and replace it with a 1/2" NPT male nipple, then cut the pex near it and install a 1/2" ball valve. You would close the new valve only to winterize. Kind that requires PEX crimp rings is $ 8, SharkBite tool free kind is $ 15.

[powercat_ras]

revised last post, should have said BALL valve not GATE valve. Fixed now.

[More-Gas]

Old-Biscuit & BFlinn181 the pic and the link to the vid really helped, the vid showed the same set up we have I wondered what that tube was for now I know.
Drained and flushed the tank then filled with white vinegar then fired up the hot water heater.
Will see if that will get check valve to open and allow hot water to the coach.
Stayed tuned and Thanks for every ones help.

[More-Gas]

Well all the suggestions was a learning experience but in the end the home brew white vinegar did not work to free up the ck valve.
So no easy fix the heater has to come out to replace the hot water outlet valve.
If I remove the valve completely when I go to winterize how do I keep the water heater from filling with the pink stuff?
Crazy questions I know
Again Thanks for all the help offered here.

[AKIQPilot]

Originally Posted by More-Gas

Well all the suggestions was a learning experience but in the end the home brew white vinegar did not work to free up the ck valve.
So no easy fix the heater has to come out to replace the hot water outlet valve.
If I remove the valve completely when I go to winterize how do I keep the water heater from filling with the pink stuff?
Crazy questions I know
Again Thanks for all the help offered here.

If you remove the check valve on the outlet of the water tank you then install a ball valve in its place. You include the ball valve in your procedure for bypassing the water heater when winterizing the motorhome. At this time you have a single 3 way valve for bypassing the water heater. With the ball valve in place of the check valve you would turn the 3 way valve to winterize and close the ball valve on the tank.

I don't see any need to replace the water heater at this time. The ball valve is about $15 and it can be installed in a location that is a couple feet from the tank so you have easier access to it. The hard part might be removing the check valve.

Another option is to remove the check valve and either clean it or replace it and put the system back in service in the original configuration. Sounds like your current configuration worked for almost a dozen years. A fresh check valve will likely last that long or more.

[More-Gas]

I bet the old valve is going to be a bear to break loose and remove and never want to do it again so I will put in a ball valve as suggested.
Thanks

[BFlinn181]

Originally Posted by More-Gas

I bet the old valve is going to be a bear to break loose and remove and never want to do it again so I will put in a ball valve as suggested.
Thanks

The tank in an Atwood WH is aluminum, the check valve is probably brass or plastic. Not sure why you think it will be so tough to remove.

[More-Gas]

Good point but was thinking of age, why worry until I get at it. Thanks