Suburban hot water heater not working

[jakejenny]

We have a Suburban Sw10de water heater in our Mountainaire that is only giving us lukewarm water on both gas and electric. Have replaced both Thermostat and manual reset and thought we had it fixed. Had hot water for just a little while and now again just lukewarm. Any ideas?

[Skip426]

Is the water temp the same at all taps in the coach ?

Some members with similar problems , have found that the winterizing by-pass valves are not properly aligned to stop the cold water from entering the hot water lines without going through the heater, others have found the outside shower is turned off at the shower head and the taps are on allowing blended water to enter the hot water side of the system.

[mel s]

Originally Posted by jakejenny

We have a Suburban Sw10de water heater in our Mountainaire that is only giving us lukewarm water on both gas and electric. Have replaced both Thermostat and manual reset and thought we had it fixed. Had hot water for just a little while and now again just lukewarm. Any ideas?

jakejenny
A bad check valve on the back of the water heater can cause that.
I just had to replace that check valve in mine, (which is in the "cold water inlet" of my Suberban SW10D water heater).
Camco 1/2 in. Brass Back Flow Preventer-23303 - The Home Depot
Mel
'96 Safari

[crolfmilton]

Did you just take it out of storage, after it had been winterized?

Check your bypass and shutoff valves to the water heater.

[dennis45]

Originally Posted by mel s

jakejenny
A bad check valve on the back of the water heater can cause that.
I just had to replace that check valve in mine, (which is in the "cold water inlet" of my Suberban SW10D water heater).
Camco 1/2 in. Brass Back Flow Preventer-23303 - The Home Depot
Mel
'96 Safari

Mel,
I am in the midst of replacing my Suburban heater from a 10 gal to a 12 gal (won't get into the reason other than its the original)
Anyway, I just became aware of the check valve you mention yesterday. I know that mine does not have one and can see no evidence that it ever did.
I never had hot water issues without the check valve. Do you know if it is standard on most heaters?

[mel s]

Originally Posted by dennis45

Mel,
I am in the midst of replacing my Suburban heater from a 10 gal to a 12 gal (won't get into the reason other than its the original)
Anyway, I just became aware of the check valve you mention yesterday. I know that mine does not have one and can see no evidence that it ever did.
I never had hot water issues without the check valve. Do you know if it is standard on most heaters?

dennis45
I don't know if a check valve is standard on most RV water heaters.

What I do know is that my WH has one in the incoming (cold) water line... and that every other RV WH, (that I've seen the back of), had one in the hot water outlet.
BTW I have no doubt that yours doesn't have one .... but I've never seen a working WH in any RV without a check valve in one or the other.

It sure would be nice if someone knew, (and would post), WHY they're used on RV water heaters...and IF they are necessary.

Mel
'96 Safari

[dennis45]

Originally Posted by mel s

dennis45
I don't know if a check valve is standard on most RV water heaters.

What I do know is that my WH has one in the incoming (cold) water line... and that every other RV WH, (that I've seen the back of), had one in the hot water outlet.
BTW I have no doubt that yours doesn't have one .... but I've never seen a working WH in any RV without a check valve in one or the other.

It sure would be nice if someone knew, (and would post), WHY they're used on RV water heaters...and IF they are necessary.

Mel
'96 Safari

Well, this is what the "Doctor" has to say on the subject.

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

[Wryly Blithe]

Don't know if this'll help, but just to throw it out there as a possible option...

RVGeeks posted a video a long time ago about this same problem. Turns out both nozzles on the outside shower were wide open but the head turned off, so no telltale flow.

This'll allow cold and hot to mix resulting in lukewarm water like you described.

I dunno... just a thought.

Good luck, whatever the problem is!

[mel s]

Originally Posted by dennis45

Well, this is what the "Doctor" has to say on the subject.
The RV Doctor: RV Water Heater Check Valve - What For?

dennis45
Thanks to you, (and the "Doctor"), I now know that my water heater check valve, (which is in the cold water inlet of my water heater), is in the correct water line and that it's "there to prevent hot water from migrating back into the cold water system".
Thanks for the link.
Mel
'96 Safari

[jakejenny]

Thanks for all of the imput. Have not had good internet because we are on the road but will check all of your suggestions. All of this started after we got south and de-winterized so it surely has something to do with that - just can't find anything that is not shut off. Anyone have any suggestions to a good RV service center in the Galveston, Corpus Christi region?

[crolfmilton]

There are probably two sgut odff/ bypass valves in your storage compartments, near the water heater. One of those is off or on bypasd.
I went through the same thing, some time ago, on my MADP.

["007"]

Here are a couple of links from QT's 1 & 2 that may help with the by-pass-valves and their operation in Newmar coachs.

#1 & #2

[Rotten-Red]

Originally Posted by jakejenny

Thanks for all of the imput. Have not had good internet because we are on the road but will check all of your suggestions. All of this started after we got south and de-winterized so it surely has something to do with that - just can't find anything that is not shut off. Anyone have any suggestions to a good RV service center in the Galveston, Corpus Christi region?

It does sound like whoever de-winterized it opened the inlet and outlet valves on the water heater but forgot to close the bypass valve. That would cause some water from the heater and some from the cross over pipe to blend whenever a hot water faucet was opened. Causing the water to be lukewarm.

[jakejenny]

Finally found a valve that did not complete get shut by getting down on hands and knees and hanging by our fingertips! Well not quite that bad but almost BUT we did solve the problem. Thanks to everyone that helped.