Furnace starts out great & then later not?

Blanco1 wrote:
Ok, camping right now & I've learned, that it's not a battery issue being the battery seems to stay above 12 volts or more & still stops blowing hot air after a while?


Yet turning it off & turning it back on seems to get the heat going again ?

So what you guys think?

Ok, I know what is going on. My heater did the same thing. I have test equipment to test the motor speed. OK. NASA checked my hi temp snap switch in their lab.OK. 11.6 in gas pressure tested with a manometer.OK. Used drills to check the gas jet size.OK. Removed all the ducts and bench tested the unit on a 50f day with the wind blowing across the heater. ( NO duct restriction), Contacted Dinosaur and Suburban tech support. Dinosaur says there is a safety built into the board that allows your heater to overheat (hi-temp snap switch opens) 6 times the heater can cycle on and off (if it still hasn't met the thermostat set temp)the board times the heater out for 1 hour. In real cold weather sit down outside next to your heater when you first start it. You will hear the roar of the burner then it will go quiet for a while then start to roar again. this is one cycle. I confirmed this with temp recorder installed inside the fire box. Fire box hits 410, snap switch opens, 390 snap switch closes as the blower continues to run. LOOONG POST.. What to do? the quick fix is to pull the heater 12volt fuse and reinstall it after the sixth shut down. This reboots the board. Suburban says the snap switch should not open. I have restricted ducts.(BS) The can the heater is installed in had all the duct openings removed. I did install solid and flex 4 inch ducting that produced 30% more heat to the registers inside the rig. I installed 2 sizes smaller main jet. These 2 things lengthened the 6 cycles but in 15f weather the heater still cycles 6 times before I can get up to t-stat temp if set at 70f. When first bringing up the temp I set t-stat to 55. when that is attained I reset the t-stat to 70. This winter I installed an extra catylic heater. No 12v needed. I only have about 40 hours of time invested in all this testing. Glad to share it. Most techs don't even know how these things work. P.S. They work perfect on a warm day at the rv shop.