Furnace keeps shutting off

[GabbyM]

We own a FR3 2016 with a Suburban thermostat. We are now experiencing temps dropping into the low 40's. (Due to Hurricane Harvey we are forced to live in the RV until the house is back in living condition) I have read the manual that is online and it doesn't help me. I turn the thermostat to auto, setting it at 74 degrees, making sure that I am showing heat on the control panel and then I press furnace. It stays on for about 40 minutes and then shuts off and won't go back on! Am I missing a step? Thanks for any suggestions you can offer!

[Gohawks]

My furnace is doing the same thing. If I reset the breaker(turn off then on again)it will start back up again and run until it reaches the set temp then shuts off and doesn't come back on again.

[Houston Remodeler]

When you say it doesn't come back on - does it blow any air at all ? or just not hot air?

[Gohawks]

I don't want to hijack the OP's thread but for me nothing comes on again.

[Scrapper]

I believe that there is a way to reset the thermostat by removing power to it for about 10 seconds. If you use the search feature at the top of the forum page, you will find there are many threads in the forums about the same problem.

[GabbyM]

The furnace turns completely off and will not come back on, even when temps in the RV are very chilly! It does not blow any air hot or cold once it shuts down.

[rockfordroo]

Originally Posted by GabbyM

The furnace turns completely off and will not come back on, even when temps in the RV are very chilly! It does not blow any air hot or cold once it shuts down.

If you have the standard analog suburban t-stats like this one, you might want to replace it with a digital.


I had a similar problem on my Roo 19. Furnace would light off once, then never again unless T-stat turned off.

I replaced it with a Honeywell RTH-111B and never had another issue.

[5picker]

Originally Posted by GabbyM

We own a FR3 2016 with a Suburban thermostat. We are now experiencing temps dropping into the low 40's. (Due to Hurricane Harvey we are forced to live in the RV until the house is back in living condition) I have read the manual that is online and it doesn't help me. I turn the thermostat to auto, setting it at 74 degrees, making sure that I am showing heat on the control panel and then I press furnace. It stays on for about 40 minutes and then shuts off and won't go back on! Am I missing a step? Thanks for any suggestions you can offer!

Could you post a photo of this Suburban thermostat with an auto setting or a model number? (NOTE: I've seen digital 'stats for Suburban tankless water heaters but not furnaces)

All the Suburban furnace 'stats I've seen are analog and have no auto setting.
Typically if it's a digital stat with auto, it is a Dometic and used in conjunction with the A/C. Sometimes those 'stats need re-initialized.

[Wilco]

It sounds like your furnace is going into Lockout. There are several conditions that can cause this. Download the service manual and follow the instructions for trouble shooting this problem. (Try Bryantrv.com for your manual.)

[rockfordroo]

Here's a manual that covers a lot of models.

[BillyBass]

is'nt possible that both thermostats are bad.i want to keep up on this thread in case it happens to me

[Gohawks]

If the thermostat was bad would it even come on the first time?

On our Georgetown it is a dometic thermostat.

[coroner 502]

I had the exact same problem with my 2017 Cherokee 304BS. It was still under warranty so the dealer fixed it. The service manager said that the "limit switch" was bad. He replaced it and no problems since.

[TimVWulp]

The furnace control board is starting to fail. Had the same problem with my furnace last fall. The furnace would light and run until the thermostat was satisfied and shut the furnace off. On the next call for heat the furnace would try to light 3 times lighting the pilot but the control board did not respond to the pilot flame signal and it lock out the furnace. I still had the 2nd year warranty that I bought from FR. The dealer replaced the control board with a new Suburban control board. If you don"t have a warranty and the board is bad have it replaced with a Dinosaur brand control board.
There have been a lot of post about bad suburban control board in the furnaces and hot water heater.

Is the TT plugged into a 30/50 amp plug or a 15 amp house plug? If 30/50 amp plug an electric 1500 watt heater works very well to heat the trailer. Be very careful if you are plugged into a 15 amp house plug with extension cord. Big fire hazard! Electric heater can be much cheaper to run than propane. This depends on what the cost of electric verses propane is by you. This time of year in the north propane can double in price.

A cheap $25 - $35 electric heater will produce the same amount of heat as the #300.00 heaters don"t get bamboozled by the fast talkers

Hope this helps Tim

[Grumpy7159]

Looking at a typical wiring diagram for a suburban heater my guess would be the module board or the limit switch. I would lean more to the module board with your symptoms (turn breaker off/on and heater starts again). The limit switch would not reset when cycling power. Interesting problem.

[rockfordroo]

Originally Posted by Gohawks

If the thermostat was bad would it even come on the first time?

On our Georgetown it is a dometic thermostat.

You'd think so, but it wasn't my experience.

[Alpine207]

We have a digital Suburban thermostat and our furnace will stop and not restart. If I turn thermostat off and then back on, it will run again. I don't know what the issue is?

[GabbyM]

Our suburban thermostat was doing the same thing, running for a short period and then turning off and wouldn't restart on it's own. In one of these threads it was suggested to make sure your propane was open all the way. After checking our propane, it was not and we opened it all the way and the furnace is now working as it should. Good luck!