Are you familiar with RV furnaces operation and what to expect?
I don't know that specific RV or which furnace but most operate a bit different than home furnaces.
Rather than start the fire and then the blower as a home furnace, RV start the blower, then a sail switch has to be blown to close a switch. Then finally after a timed period with good air flow, the gas valve opens and fire starts.
We can often find RV techs who seem to know nothing! If you get one of those, they may not know where to start!
If it feels right, you may want to do some looking for yourself, rather than leave it at a dealer for 2-6 weeks!
The furnace will have a label on it with the brand and model. Using that info, do an online search for a manual for troubleshooting!
From what you tell us, I might guess at a couple things. When the blower starts, the sail switch is an actual "sail" sticking down into the airflow and it starts the timing.
However, they are semi-famous for getting gunk like hair stuck on the sail, so it doesn't move to close the switch and the controls time out before fire is lit. Do this three times in a row and they often have to be reset to do it again!
Possible other problems like a bad board or the gas solenoid doesn't open to let the fire start, but I start with the low ball ideas until proved!
Having the manual is a key to me as there are small details which are easy to miss and that throws us into work and expense we don't need.
Sometimes cleaning the dog hair off the sail is enough to fix it??
