I have a 10 yr. old mobile home with a butane furnace. The furnace lights fine. When the burner lights and burns, the blower will come on but won't run a full cycle. It runs and shuts off, then back on and off instead of coming on and running a cycle until thermostat kicks it off. I've put 3 new switches a new gas regulator and thermostat on it. It's dollering me to death and I still have the same problem. I've had a repair man out twice and he just guessing by trying trial and error. Has anyone ever had the same problem?

Have you cleaned the flame senser?, also where it is mounted to furnace,unscrew and tighten back up to be sure of a good ground,, also check the antisapater,(bad speller) in the thermostat.its a little dial in stat,, but if you have a digital stat you won`t find one, also jumper or tie together the white and red stat wires ,this bypasses the stat to see if furnace work well without the stat,if work OK you might want to make sure all wire to stat are tight,, maybe the stat is bad,,

Just because the thermostat is new,don`t mean its good

There are several things that can cause this to happen, one of the things that can cause it but is overlooked so often and that is a dirty air conditioning evaporator coil. If the coil is dirty the unit will turn off by way of the limit switch, in a few minutes it will cool and the limit will close again and the unit will come on then the whole things happens again. It will do this three or four times and then the logic board will put it into lock out mode and it will stay that way for several hours. But if you turn off the power to the unit, (like turning off the switch one the furnace) this will reset the logic board and the whole thing will start over again.

I am not saying that this is you problem, I just know that it does happen and is almost always over looked. Good Luck.