Water heater fuse location

Paul Cartland · 05-24-2023, 05:19 PM

I have a 2021 Cougar 30 RLS. The water heater is working on electric but not on gas. It is not firing at all. I tried to find the fuse to verify that it's getting 12V but there isn't a fuse in the panel that says water heater. Does anyone know what to check?

Thanks
Paul

KevinRC · 05-24-2023, 11:51 PM

I have a suburban SW6D which has a pair of reset switches outside in the water heater compartment.

I have only Gas so behind the rubber cover of the reset switches, the one for electric is blank.

Kevin

Paul Cartland · 05-25-2023, 06:13 AM

Thanks. My SW6DEL Has both reset buttons. The gas reset button doesn't appear to work. However, I'm trying to determine if it has the 12v power for the gas side and can't find a fuse that is for the water heater.

Thanks
Paul

**chuckster57** · 05-25-2023, 06:39 AM

Your control board will be on the back side of the water heater.

KevinRC · 05-25-2023, 10:26 AM

Find the reset switch and take a reading RE: voltage there.

KevinRC · 05-25-2023, 10:27 AM

Quote:

Originally Posted by chuckster57

Your control board will be on the back side of the water heater.

Is under the sink

LHaven · 05-25-2023, 11:21 AM

OK, everybody is talking around the OP's question, but nobody is answering it.

He's looking for the fuse, in his fusebox, that runs the 12V (board, propane management) section of his water heater. His isn't labeled. Neither is mine. Now I'm wondering myself, and I don't have an answer.

His 120V electric operation works fine, but not the propane.

**chuckster57** · 05-25-2023, 11:27 AM

Quote:

Originally Posted by KevinRC

Is under the sink

If your water heater is under the sink, the control board should be under a cover normally taped to the styrofoam insulation. Easy to check for voltage. If 12VDC is there then the board has failed.

**sourdough** · 05-25-2023, 01:10 PM

https://www.google.com/search?q=2021...id:XNlN5MnimLw

At 6:59 you will be looking directly at the water heater which isn't under the sink.

OP are any of the 12vdc fuses lit up? Is the switch on for it in the control panel and is it lit up? Here is a link to the manual for a SW6DE, look at page 5 at the 12vdc and it might help you in troubleshooting;

https://manuals.heartlandowners.org/...ter%20sw6d.pdf

Paul Cartland · 05-27-2023, 09:53 AM

Thanks Sourdough. Mine is not under the sink. There are no fuses lit in the panel. My Cougar has several in line fuses behind the In Command cover in the pass through. I wondered if it was one of those, but I wouldn't think so since the water heater is standard.

LHaven · 05-27-2023, 11:20 AM

Oh! Suddenly inCommand in involved!
Since inCommand does control both sides of the water heater, have you eliminated a bad relay there as the cause?

Paul Cartland · 05-27-2023, 11:30 AM

I have not eliminated a bad relay. Is there a troubleshooting process other than replacement?

Thanks

LHaven · 05-27-2023, 11:32 AM

Sure -- find the wire connection points for the gas heater on your model main board, then use a multimeter on them while someone else turns it off and on from the DCM (or your phone app).

Paul Cartland · 05-27-2023, 11:39 AM

I found the BCM troubleshooting guide. It gives me this pin values but doesn't seem to mention how to troubleshoot relays.

LHaven · 05-27-2023, 11:53 AM

Simplest start is to check 12v between the ground and gas-heater output pins while you use your app to turn the gas heater on and off. If you don't get 12v with it on, there you go.

It may not be straightforward, though. On my model, the water heater connections are on a plug, not one of the naked screw terminals, so access is harder. In this case, I'd remove the plug and run the same test between the WH ground and WH electric side pins. If the test gives proper results you can assume the board isn't sensitive to the absence of the cable, and test the gas side.

You can identify the pins by visiting the inCommand website and downloading the "troubleshooting guide" for your model inCommand. (Oh yeah, you already did that.)

Paul Cartland · 05-27-2023, 12:08 PM

Thanks LHaven. The pinout I found for the BCM doesn't match mine. It shows 4 pins and mine has five on a ribbon cable. It has 12v on two pins when both gas and electric are selected. I removed the cover with the reset buttons and there is 12v on the terminals of one reset button and 0 v on the other reset button. The manual for the heater shows the reset button that has 12v is for the gas. The reset button with 0v is supposedly for the electric.

LHaven · 05-27-2023, 12:35 PM

You should visit the inCommand website and download the manuals that match your model. Mine is an NCSP35 and has the five-pin cable (see drawing excerpt). If those are the right two pins, super.

The reset button is a breaker switch on the +12V feed. Can you get to both terminals of each? Turn all WH power off, (better, disconnect the cable at the BCM), then check continuity (ohms) between the two pins of each switch. The electric side should read 0 or some fraction ohms, because we know it works and it's reset. I bet the gas side will read open, despite you pressing it to reset. If so, then that switch is bad.

You can further assure this by shorting those pins temporarily and turning the gas on -- if the switch is the problem, it should work.

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