Furnace issue

[JohnandPaula]

We purchased a 2024 model 3761 FL a couple of weeks ago and when we got it home we are having a problem with the furnace. When i go to the in command and turn the furnace on it starts fine and starts blowing heat but it will turn off in about 1 hour and won’t start back. If I turn the HVAC off for about 30 minutes it will start back up. I have checked propane pressure by checking the stove and it’s all good. It cuts off before it reaches my temperature setting. Any suggestions?

[Foldbak]

You say you're running the heat pump as well. So you have it set to Electric heat? If so the gas furnace will automatically kick in to help the heat pump if the temp differential is more then 5 degrees, I believe. Once it gaps the differential it lets the heat pump do the rest.

At least that's how mine works.

[JohnandPaula]

I have it set to heat and gas.

[ChuckS]

When you set a Temp Setpoint for the furnace be aware it only uses the remote temp sensor for Zone 1 to get actual room temp feed back... The location of the sensor will affect its accuracy ( which is about +/- 5% tolerance )

Since you have the Global In Command controlling your HVAC it has been and still is a very quirky HVAC control method.

The units with separate thermostats are much better.. Alpines have been using In Command for several years now and the issues are still not resolved.

If furnace doesn't come back on until you cycle the display Off and On then I would do a full Hard Reset of the In Command system..

The ONLY way to do this is remove shore power and disconnect batteries.. wait a few minutes and then connect battery, connect shore power and fire up In Command and further evaluate.

Even though you have Coleman AC units the In Command uses a gateway to process the info from the In Command display up to the AC units control board via each gateway for each AC..

The furnace is controlled via Zone 1 roof AC gateway...

This info in this link is something you are gonna want to be aware of down the road.... regarding In Command and HVAC control

https://in-command.net/in-command-w-global-connect/

This PDF is also one you want to read and keep.... The EOL resistor and connections on the gateway can become loose, corroded, etc and affect both heating and cooling operation

https://asasupportdocs.blob.core.win...3%20NCSP35.pdf

[Bourbon County]

For transparency; I don't have the in-command system and after all I've read, I'm glad I don't.

Chuck just laid out in great detail what I suspect. If the furnace lights and burns for an hour, there aren't that many things that will knock it out at that point. One would be fuel pressure which you already checked, another would be the high limit temp sensor. The high limit is more a result than a cause. If it opened, it likely means there isn't enough air circulation to keep the heat exchanger below whatever the high limit temperature is. This device is a simple bi-metallic disc and should reset itself once it cools a bit.

I believe this is the third thread in the past couple of weeks about very similar problems. I wonder if there's a cycle time watchdog timer built into the firmware on the in-command or the furnace motherboard?

You mentioned that it ran for about an hour; that seems like a very long cycle unless it was very cold inside the coach when you first turned the furnace on. These furnaces normally heat up pretty quickly. It won't fix anything, but you might try starting a stop watch when the furnace lights and time the actual cycle time. When you are able to reset the system repeat the timing. The goal will be to determine if the problem is consistent and repeatable.