Checking suburban water heater thermostat

Jerapais69 · 02-19-2019, 09:37 PM

All, I think one of my thermostats is not working. I can heat with gas, but not electric. Exactly How do i check it with a multimeter?

MTK46 · 02-21-2019, 04:04 PM

First thing is to check the little black rocker switch that's at the heater. Is it on? You are plugged into 110V right? If all of that is okay you need to remove the small black cover that's next to the switch. If you have 110v at the heating element the element is bad.
I just had to replace mine a few weeks ago.

Jerapais69 · 02-21-2019, 04:16 PM

Thx. Will check! I changed heating element last week. Still didn’t work.

MTK46 · 02-21-2019, 04:44 PM

Also check the 110v breaker inside your RV. Should be one dedicated to the water heater.

Jerapais69 · 02-21-2019, 05:01 PM

I did that but thx!

MTK46 · 02-21-2019, 05:35 PM

Have you checked your inside switch for the hot water heater? Does it light up when turned on?

elliott-maine · 02-25-2019, 04:35 PM

The switch under the outside cover must be on. It too commonly fails due to corrosion. If yor turned the heater on while your tank was empty, the heating element must be replaced again. 1 second is too long.

onetonford · 02-25-2019, 06:01 PM

Here is a picture and the unit for the 110V is blown they sometimes do this when the element shorts out. These are found under the cover with the rubber plugs in it.

Jerapais69 · 02-25-2019, 06:13 PM

Looked at that. Are you saying the 120v IS blown on your pic? If so, how can you tell without a multimeter?

onetonford · 02-26-2019, 12:01 AM

expand the pic and to the left you can see the wire from the top reset to the bottom therm is blown in two. also if you do buy a new unit make sure they sell you the 120V unit as they are different even thou they look the same.

Jerapais69 · 02-26-2019, 12:23 AM

I see it now. No need for a multimeter here. Thx. I don’t have that. I’m totally perplexed. Heating element is fine as I replaced that too.

onetonford · 02-26-2019, 09:04 AM

The next weak link in the circuit would be the little rocker switch on the outside of the heater. I know that my unit has the power cord plugged in under the sink in the cabinet I would unplug it and plug a light into it to see if it was working other wise there is no other spot in that circuit that could be bad.

Jerapais69 · 02-26-2019, 09:31 AM

I’ll try that. Thanks.

MTK46 · 02-26-2019, 04:19 PM

Quote:

Originally Posted by onetonford

Here is a picture and the unit for the 110V is blown they sometimes do this when the element shorts out. These are found under the cover with the rubber plugs in it.

I had to replace my 120V heating element and it doesn't look like what you posted.
water heater element.jpg
Is round.

Jerapais69 · 02-26-2019, 04:44 PM

I didn’t post a heating element unless you mean someone else.

onetonford · 02-26-2019, 05:21 PM

Quote:

Originally Posted by MTK46

I had to replace my 120V heating element and it doesn't look like what you posted.
Attachment 947
Is round.

Those are the reset/thermostat.

MTK46 · 02-26-2019, 05:50 PM

Quote:

Originally Posted by Jerapais69

I didn’t post a heating element unless you mean someone else.

Referring to onetonford post