Suburban water heater questions - Montana Owners Club

mtlakejim · 03-03-2020, 07:08 PM

Ok folks we have a Suburban model SW 12 DEL electric/gas water heater that is giving a minor fit.

The unit has become inconsistent in that it will heat water fine for a few days then it will not heat well. I can let the unit cool completely down and reset and it will work fine for a few days then have an issue again. Any thoughts?

Related, I have been looking at the wiring diagrams and it appears that the electric is totally independent of the gas which makes sense as one is 12v and other is 110v. As in there is no shared devices right? Separate thermostats and all?

One thought I did have though is if one thermostat was allowing over heating it would kick off BOTH high range switches?

Also, are the thermostats simply sitting against the outer wall of the tank like a household hot water tank thermostat? Can there be an issue with good contact with the surface or is it usually just a thermostat that goes bad? We are full time so the unit gets a real workout, mostly on 120v.

mtlakejim · 03-03-2020, 07:12 PM

One other question. They sell thermostats that are called high temp and are set about 10F higher than original factory stats. Are these a good or bad idea?

BB_TX · 03-03-2020, 07:57 PM

A couple of questions.
Is it acting up on both gas and electric? Or just one of them?
When you say reset, are you having to press the reset button on the hi temp cutout(s)? Or saying the cool down seems to temporarily reset (clear) the problem?

rohrmann · 03-03-2020, 08:05 PM

I'm making an assumption here, but you did not say for sure, but if you are running with 120 volt power, it could be the 120 volt thermostat, and is very easy to replace as it only has one stud with a nut holding it onto the tank. I would not go with anything but the Suburban thermostat. The 120 volt thermostat is mounted to the left of the 12 volt thermostat and is part number 232306. Just in case the gas side is the problem, the 12 volt thermostat is part number 232282 and is mounted the same way on the right.

https://www.amazon.com/Suburban-120V...AXDKFR2ZBFJ52G

https://www.amazon.com/Suburban-SB23...omotive&sr=1-1

I don't think it will be a burnt switch that is located at the lower left of the tank outside because it would just burn in the clear and you would not be working on 120 volts at all. I also don't think it would be the electrode either.

mtlakejim · 03-04-2020, 07:38 AM

It’s a combination of the two. It’s an inconsistent problem which is part of frustration

mtlakejim · 03-04-2020, 07:43 AM

Yep that was direction I was heading. Replacing both thermostats. Looks like one piece with limit switch? It is raining cats and dogs so haven’t been able to diagnose further. But great to get the information thanks

I have already cleaned tank and replaced electrode. Tank was fairly clean so don’t think element is burned but I do have replacement already just need a socket to fit

BB_TX · 03-04-2020, 08:10 AM

You are correct that the gas and the electric are electrically independent of each other, with one exception and that is the inside switch panel which is 12 vdc to both switches. The 12 vdc switch for the electric side energizes a relay at the water heater that in turn sends 120 vac to the heating element. See the diagram below. Possibly there is a bad/loose wire connection to that panel. They also use a common 12 v ground at the water heater junction box that could also have a bad connection.

You might also check the two thermostat/hi temp cutouts that they are tight against the tank. Some have reported in the past that one or the other was not tight and subsequently not controlling the temp correctly. The thermostat/hi temp cutout device has two functions. It is a thermostat controlling the temperature. And it is a hard cutout for too high of a temperature and requires a manual reset via the pushbutton on it.

mtlakejim · 03-04-2020, 09:13 PM

Quote:

Originally Posted by BB_TX

You are correct that the gas and the electric are electrically independent of each other, with one exception and that is the inside switch panel which is 12 vdc to both switches. The 12 vdc switch for the electric side energizes a relay at the water heater that in turn sends 120 vac to the heating element. See the diagram below. Possibly there is a bad/loose wire connection to that panel. They also use a common 12 v ground at the water heater junction box that could also have a bad connection.

You might also check the two thermostat/hi temp cutouts that they are tight against the tank. Some have reported in the past that one or the other was not tight and subsequently not controlling the temp correctly. The thermostat/hi temp cutout device has two functions. It is a thermostat controlling the temperature. And it is a hard cutout for too high of a temperature and requires a manual reset via the pushbutton on it.

I was wondering about the tight against the tank issue for sure but the interior switches is another possible. Thanks for the information!

PeteandJoan · 03-04-2020, 09:34 PM

Quote:

Originally Posted by mtlakejim

Ok folks we have a Suburban model SW 12 DEL electric/gas water heater that is giving a minor fit.

The unit has become inconsistent in that it will heat water fine for a few days then it will not heat well. I can let the unit cool completely down and reset and it will work fine for a few days then have an issue again. Any thoughts?

Related, I have been looking at the wiring diagrams and it appears that the electric is totally independent of the gas which makes sense as one is 12v and other is 110v. As in there is no shared devices right? Separate thermostats and all?

One thought I did have though is if one thermostat was allowing over heating it would kick off BOTH high range switches?

Also, are the thermostats simply sitting against the outer wall of the tank like a household hot water tank thermostat? Can there be an issue with good contact with the surface or is it usually just a thermostat that goes bad? We are full time so the unit gets a real workout, mostly on 120v.

I have the same heater and also have been having erratic problems with the 120v heating side. I am replacing both (gas & elec.) high temp sensors and the heating element and outside switch. Will sand off any corrosion where sensors mount to ensure good contact. That may be the problem by itself. Will flush tank and replace anode rod also. Ground seems good. Should be good to go for another 5 yrs.

PeteandJoan · 03-04-2020, 09:39 PM

PS: Be careful removing the element. It is hard to get a good grip with socket and could slip off and bust some knuckles. Found a good one on Amazon and worked great...easy off. My socket was too thick-walled and would not fit into the opening around element.

mtlakejim · 03-04-2020, 09:52 PM

Quote:

Originally Posted by PeteandJoan

PS: Be careful removing the element. It is hard to get a good grip with socket and could slip off and bust some knuckles. Found a good one on Amazon and worked great...easy off. My socket was too thick-walled and would not fit into the opening around element.

I'll keep that in mind thanks

mtlakejim · 03-04-2020, 09:52 PM

Quote:

Originally Posted by PeteandJoan

I have the same heater and also have been having erratic problems with the 120v heating side. I am replacing both (gas & elec.) high temp sensors and the heating element and outside switch. Will sand off any corrosion where sensors mount to ensure good contact. That may be the problem by itself. Will flush tank and replace anode rod also. Ground seems good. Should be good to go for another 5 yrs.

Sounds like the thing to do to me.

rtrench · 03-08-2020, 01:10 PM

Check the on off switch located on the heater outside. Mine shorted out and no hot water. The switch cost about 5.00 dollars. The switch does bad every so often

paulinbaja · 03-08-2020, 01:56 PM

I had to take the socket and grind the outer wall to get it to fit.

Clark 2012 346LBQ · 03-08-2020, 02:08 PM

Check the iodized rod once we pulled ours and did a proper flush then replaced the rod with new it fixed our problem

PeteandJoan · 03-08-2020, 08:45 PM

Man there was a bunch of white particles in that tank! Flushed and decided to flush again the next day a whole lot more came out. Looking pretty clean now. Not camping so have a lot of time....between 3 funerals

rohrmann · 03-08-2020, 09:48 PM

Get one of these for flushing the water heater tank. Works great. https://www.amazon.com/Camco-Rinser-...3725362&sr=8-1

And, for removing and installing the electric element, one of these wrenches work very well. https://www.amazon.com/Camco-Residen...3725574&sr=8-3

BB_TX · 03-09-2020, 08:03 AM

And they are both very inexpensive.

PeteandJoan · 03-09-2020, 10:12 AM

The heating element socket listed above is the one I call the knuckle-buster. Tried it. It fits too loose and slips off, also needs to be a little longer for the crossbar to clear the side of the rig. Got another that fit perfectly. Saw a video with a guy that used that one and he had a busted knuckle...was too late for me ..I had already ordered it. Gonna send it back.

You may also like: