Suburban Furnace died (resolved)

[southernlady5464]

Today has been the trip from ****. Colombo (our rig) never fails, he always needs just “one more thing”. Woke up to a dead furnace. Suburban SF42 Low Profile Heartland Landmark 2017 Charleston but Suburban is used in many manufacturers.

We were on our way back from a failed trip to Goshen (LONG STORY AND NOT AFFINITY’S fault). Anyway we stopped overnight at a service plaza in Ohio since going from our home park in WV to Goshen in Winter is not a one day trip.

So we spent most of the morning trying to find a dealer willing to look at it, nope. Although one did help us figure out it probably was not the circuit board. One did have a a sail switch for us to buy. No limit switch, that we will have to order. But that meant going down toward Dayton and across…out of normal route. On the way home, we are stopping for a couple of space heaters just in case.

Funny thing, we did discover our heat pump kicked in at 34 degrees. We had lots of blankets and the fireplace. Adding a space heater to that and we’ll be fine til we get it fixed. Our campground owner knows of a mobile tech who can help but not this week.

Any of our technically adapt RV friends…helpful info is welcome.

 

[danemayer]

Can you provide detail on the furnace failure? For example, does the blower run? Is there an ignition attempt? Do you get any hot air at all? Have you verified propane flow to the stovetop burners? Is the thermostat you're using for heat one that you've previously used for heat?

 

[cbramsey]

No, blower doesn’t run. No hot air at all. Induction cooktop so no propane to stovetop. Yes, been using this thermostat for almost 5 years full time.

 

[southernlady5464]

The only propane appliance besides the furnace is the water heater and we used it on propane this morning. We can also run our propane generator.

 

[danemayer]

If no blower, next thing to check is fuses. The 12V DC for the blower comes out of the main fuse box.

 

[southernlady5464]

Thank you.

 

[wdk450]

Page 30 of this manual has a step-by-step troubleshooting tree:

https://manuals.heartlandowners.org/manuals/Heating-Cooling/Furnace/Suburban/Suburban%20FURNACE_Service-and-Training-Manual-11-05-2015.pdf

 

[southernlady5464]

Fuses are fine, according to my husband.

 

[danemayer]

If the fuse is ok, you'll probably be able to confirm 12V DC at the control board on the furnace. If so, and if you can confirm the ground at the control board (page 31 of the manual), then what's left is the control board. The reason to confirm 12V and ground is that the failure may be loose connections where the furnace is connected to the trailer wiring. Bad connections and failed boards are both fairly common.

Furnace failures can also be a result of low voltage, but since the water heater is working on propane, and you haven't mentioned problems with lights, it's probably not that.

 

[southernlady5464]

Furnace failures can also be a result of low voltage, but since the water heater is working on propane, and you haven't mentioned problems with lights, it's probably not that.

Actually you may have hit on it. Charles tried to kill the batteries this week. It was too late to do anything last night but we are off to Sam’s this morning to buy new ones. I’ll let you know if this resolves the issue.

 

[danemayer]

Even if batteries are low/dead, you should be getting 13V or so from the Power Converter. You can check this on the auto-level panel - 13.2 volts or higher while on shore power, or press the test button on the tank monitor panel - the battery/converter level while on shore power should be 4 lights.

 

[cbramsey]

I checked the Lippert panel after I installed 2 new batteries and was surprised to see the voltage.

Does this mean my converter might have gone bad??

 

[danemayer]

If on shore power, 12.3 indicates no power from the converter. Near the batteries is a row of small 12V mini circuit breakers covered by red rubber boots. One has a teeny tiny reset button that's a manual reset.

After pressing it, the reading should be 13.2 or higher. If no change, check the on board fuses on the power converter.

We have an Electrical user guide that explains all this in more detail with photos and drawings. On the tools tab, select HUG - Heartland User Guides.

 

[cbramsey]

Update: Mini breaker had popped. Reset it and voltage on Lippert panel now reads 13.2 - 13.3 volts.

Furnace still not working. Next step is checking the fuses on the power converter which I will do during daylight hours tomorrow. We have tank heaters and I have a space heater in the underbelly for tonight to keep pipes unfrozen.

Thank you for the guidance.

 

[danemayer]

If 13.2, no need to check fuses on the converter. It's working.

 

[wdk450]

Also videos on You Tube on troubleshooting/repairing Suburban RV furnaces (and most other RV items). Use You Tube search bar.

 

[southernlady5464]

Mobile tech came out this mornin. It was the sail switch.

 

[danemayer]

Mobile tech came out this mornin. It was the sail switch.

Glad it's working now. But I'm wondering about the fix as I think the blower has to run to push air which activates the sail switch. I don't think a failed sail switch would keep the blower from starting.

I'm guessing that in the course of working on the furnace, a bad wire connection was restored and now you have 12V to the furnace.

If the problem recurs, look at the wire connections.