Furnace runs too often

[Slufoot733]

Recently, on a cool weather trip, we used our furnace (Atwood Hydro-Flame 8500)continually for the entire weekend. We noticed that it starts, ignites and blows warm air. Good. After awhile it shuts off. Then about one minute later it starts all over again. It heats the trailer but seems to start and stop way too often. My old SOB didn't not do this and it had a same brand furnace. The manual that came with the unit is next to worthless for troubleshooting. Any ideas would be appreciated.

KT

[ole dude]

Is there some kind of cool draft that is bathing the thermostat, how big is the hole behind the t'stat and is there a chance of a draft through that hole. Is the warm air blowing on the t'stat when the heater is on. Just sayin.

[Slufoot733]

old dude, all good points. The T-stat is located on an inside wall with screws, no hole behind it. As for warm or cool draft on it....possible. I don't think so but I'll have to check. That certainly could explain the on - off cycling.

Thanks,

K

[camper4]

Check for partially blocked heat vents. If the air does not flow freely through all the ducts then it can cause the furnace to overheat which can cause your problem.

[oldelmer1]

Some T-stats try to keep the temp at exactly the setting, say, 70, if the temp goes down to 69, it will kick back on to heat the area up, constantly going on and off. Some T-stats have a jumper inside that you can change this setting, so if set at 70, the T-stat will wait till the temperature gets to 68 or 67 before it kicks on. Dont know it yours has this jumper or not, maybe read the manual for it to see if this is mentioned or not.

[Ozz]

Tom is right on, most thermostat have a 'heat anticipater' the old ones, like the round Honewell T-87-F series had an adjustable slide, a very small heater. Now they have micro-switches, and jumpers. Or not, some are not adjustable.
See what numbers and info you can find on it and I will see what I can find out.

[Countryfolks]

Ours is right by a slide. I put a plastic sandwich box over it and it stopped the constant cycling. I just taped one edge so it could be opened from the bottom.

[richfaa]

Ours did that when the propnae pressure was low due to to a combination of cold weather and low propane in the tank. Everyting else will work fine on low propnae pressure but not the furnace.

[SlickWillie]

Ours came with the old type analog thermostat. After one night in the fiver with it cold, I installed a Hunter electronic thermostat; problem solved.