Furnace not working

[Beauty & the Beast]

2019 momentum 376th
With 3rd ac
Purchased in April 2020 and picked up in Florida from older couple hardly used excellent condition
Stove works, outdoor stove works, fridge works on gas, hot water tank works on gas
From what I have read u put it on heat then auto nothing happens and shows error under the icon on screen, no thermostat except for the one on screen i turned up
First time I have had to use it
Took The cover off and made sure the little switch was in the on position no noise nothing
Any suggestions
Unit is under hot water tank outside
Please help
No warranty
All 3 ac's work great

[Grandesigner]

If you can access it, I would check that all the connectors are making good contact. Last 5W I owned had poor contact on the limit switch and fired right up after pulling and replacing both wires...
Free bump for the experts to pipe in.

[Beauty & the Beast]

If you can access it, I would check that all the connectors are making good contact. Last 5W I owned had poor contact on the limit switch and fired right up after pulling and replacing both wires...
Free bump for the experts to pipe in.

Will try that and test the power
Have the last 2 weeks off in December and will need the heat to work for our trip
The fireplace got a workout this weekend but it's on the opposite end of rv