Heating Question (Cycle on and Off)

I think your cycling on and off is due to heat loss. Do you have a digital or analog thermostat ? We have 2 different TT's (see my signature) and the Jayco has a thermal package and does not cycle on nearly as much as the Shasta. Both have digital thermostats. Keep in mind the furnace blower will run before the burner ingnites and continue to run after the thermostat is satisfied. This is for safety to cleat any LP gas in case the thermocouple or electronic ingnitor fails to prevent a gas explosion.
You may want to try a small electric heater to supplement the gas furnace and take the extreme chill out so the furnace can keep up.

Analog thermostat. Controls the AC Unit as well. Yeah I'm figuring heat loss but I wasn't sure. I know it was cold last night. LoL Definitely have to figure out something else cause not sleeping is getting old.

Wish we'd actually have some May temps. Not January temps. LoL

Your experience is pretty normal. Yes, RV do have that much heat loss. As stated above, the blower will start immediately, the furnace will heat to temperature, the furnace fire will shut down once the thermostat temperature is reached, the blower will continue to run a bit longer and then finally shut off.

From the time the furnace fire goes off, your camper begins to experience heat loss, even though blower is still running.

Most wall thermostats have some way of setting the "on and off" position and every wall thermostat does it a little different. But they can all be set to turn on and off with different temperature ranges. Your's may be set to turn on within a 5 degree range, thus a shorter cycle. You may increase that to a 10 degree range, making for a longer cycle. Just remember though if you increase it... If you set the thermostat at 70 degrees, this is the turn off point. It will heat the room temperature 70 degrees and then shut off. When the room temperature reaches 65 degrees, it will fire back on. This might make for a shorter running cycle and more often, opposed to a 10 degree difference and a longer running cycle, but the temperature difference may kick on at 60 and off at 70. 10 Degrees is a big change. So the short cycles are actually better so you don't have the drastic temperature swings.

I don't know how yours is set, but that's what's going on.

X2 on heat loss. We've had a string of RVs over the years and concluded that having double pane window glass made quite a difference in efficiency that translated into much better comfort level including how often the furnaces cycled. We, too, don't let outside temps get in the way of taking the Winne out and in sub-freezing weather it's noticeable how the front glass frosts over (lots of humidity inside an RV) and the double pane doesn't. That's become a must have for us.

Poor design in ours as for where the windows and thermostat are pretty much. LoL. Again....If we had normal weather for this time of the year I'd be ok. LoL Its not a big deal for the most part. I'll have to have some wine before bed. That tends to make me sleepy!

Check to be sure that one of your heat output registers is NOT blowing directly on or toward the thermostat. That will make it cycle more often.

get a small ceramic heater / fan to "supplement" the furnace. It will likely keep the heat circulating better, reducing the cycling and save on propane use a bit... plus it might be a bit quieter during its operation.

It might be the following:
On an 04 model, it might have non-digital thermostat where it would have a heat anticipator which is a small metal clip that slides in both directions.
In older manual types of thermostats, it controls the length of the cycles. This link shows a picture of one. Click the arrow on the right for picture 2.
https://www.familyhandyman.com/heating-cooling/furnace-repair/how-to-adjust-a-mechanical-thermostat/view-all

You also need to make sure a heat vent is not blowing on the thermostat.

If you have the age old cheap Atwood piece of **** thermostat take it out and throw it as far as you can. Go to a big box and buy a non-programmable digital thermostat. It's an easy switch and will at least give you accurate temperature control.