Hi Huck, after you light
it a couple times it will be second nature to you if it cooling down or not. Haven't seen anyone else tell you but if your RV has been sitting for a while the propane
kind of gets an air bubble in the lines. I nornally light
the stove first to bleed the line as the stove uses more PL faster than the refer. Once the stove lights
off, shut it down and then light
the refer. I've had a number of RV's in 30 years with both Domectic and Norcold refers. Some had an indicator at the refer that showed the burner was lit and some didn't. I never had a problem knowing if they didn't light off even with the ones that didn't have an inside indicator. I could hear it burning or feel the heat after opening the outside access panel. In all the years I've only had two problems with my refers working. One thurmo coupler quit and kept it from lighting
and another one while trying to light it gave off the "dreaded" ammonia smell......dead and a $1000.00 fix meaning a new unit but it was 15 years old.
I do two things now. I carry an extra thurmo coupler, quick fix and cheap and I keep a thermomitor in the box to keep tabs on the temp.
Beside a spyder making a web in the burner area (water heater too) they are pretty much bullet proof.