If this is a new rodeo for you, there may be room for confusion as RV furnaces work far different than at home!
Step one for home, the fire lights and finally the blower but in RV the blower comes on first and make air flow. When that good air flow is sensed by what is call a "sail switch" , then a timing process starts before the gas valve is turned on and the gas lit. Finally after a bit of cold to cold air blowiing around, you get warm air!
There are a number of safety reasons for this difference but it does leave some room for confusion on what to expect and we may shut it down before the process works it's magic OR there may be a true problem.
Since you mention the dog and hair?
One of things which can happen is the sail on the sail switch gets hung up with a hair ball!
Lots of different shapes, etc of sail switch but the idea is a micro switch with thins big "sail" that moves with the airflow and pushes on the little black button of the switch.
You can see how dog hair can stick on the sail? But before panic and saying that is true, try to think back and review if it might also just be not waiting long enough?
I can vouch for it seeming to take FOREVER for the heat to get there when you wake up cold and it sends you cold air! Probably less than a full minute but it feels like forever!
EDIT/ CORRECTION?
Sorry I skipped to dog hair instead of daughter hair but it works the same. No I DID NOT mean to call the daughter any names!
