Furnace cycles

[twe412]

Hello everyone,

this is our first winter in our London Aire, and we like it way better than our lil old Winnebago, insulation is nowhere near as bad. However, I have been wondering about the furnace in our coach. Right now, its about 40 degrees outside (not bad, huh?), the thermostat is set to 70, but I would say its about 60-65 inside (unfortunately I dont have a thermometer), and the furnace kicks in every 5 minutes, for about 45 seconds (net propane burning time). I think its not bad, considering in our Winnie it would run for 5 minutes every 45 secs .

I know the thermostat can be adjusted so that the furnace cycles can be longer, if so desired, so Im wondering, is 45 seconds long enough for it to warm up enough and be efficient? Maybe if adjusted to run for a little bit longer, it could get the house warmer, and last for longer between cycles, maybe saving some propane? Because at 45 secs, the air coming out of the vents is barely warm, and I know the furnace can get the whole house 10 degrees warmer in a little more than 5 minutes, so I know it can get pretty hot in here.

What experiences have you had with thermostat settings? What seems to be the most propane efficient setting? Because at about $80 bucks, filling up the tank isnt very cheap, not with a newborn on board

Art

[JohnBoyToo]

While the cycle time can be adjusted... sometimes the low tech approach works too... Wear more clothes

just kidding -
the cycle is determined by getting the surrounding up to temp and then shut down...
and that is a function of the size of the unit and the area to be conditioned..

sometimes the unit is too big and warms too fast, so it short cycles...
if unit is too small, then it long cycles - i.e. runs constantly..

If right sized, is it possible you have a vent pointing right at or close to the thermostat ?

One thing you can try is close down a vent or two closest to the thermostat forcing the heat out further from the thermostat.... therefore it will take more time for the heat to come back to the return register and the thermostat...

good luck...

[450Donn]

What thermostat does your coach have? If it one of those cheap RV brands, consider switching over to a better one, like the Hunter Douglas as used in homes. There are hundreds of posts about how to change thermostats from the RV junk to a quality one. Wiring is very simple and the change over only costs about 25 dollars. So it is a very cost effective upgrade.

[twe412]

Originally Posted by JohnBoyToo

While the cycle time can be adjusted... sometimes the low tech approach works too... Wear more clothes

just kidding -
the cycle is determined by getting the surrounding up to temp and then shut down...
and that is a function of the size of the unit and the area to be conditioned..

sometimes the unit is too big and warms too fast, so it short cycles...
if unit is too small, then it long cycles - i.e. runs constantly..

If right sized, is it possible you have a vent pointing right at or close to the thermostat ?

One thing you can try is close down a vent or two closest to the thermostat forcing the heat out further from the thermostat.... therefore it will take more time for the heat to come back to the return register and the thermostat...

good luck...

We try And in this area, everyone goes crazy when it starts getting below 50, jackets, hats and gloves everywhere. We dont do well with cold weather

Our furnace is well sized I think (dont remember if 35k or 40k BTU), and it really doesnt have any problems heating up the whole house very quickly. Ive set it to almost 80 degrees before and it gets hot hot very fast with no problems. And the tstat is in a good place, no vents pointing straight at it.

Originally Posted by 450Donn

What thermostat does your coach have? If it one of those cheap RV brands, consider switching over to a better one, like the Hunter Douglas as used in homes. There are hundreds of posts about how to change thermostats from the RV junk to a quality one. Wiring is very simple and the change over only costs about 25 dollars. So it is a very cost effective upgrade.

Yep, cheap RV tstat (Emerson). Ive been looking into replacing it, I read a few of those articles about Hunter thermostats and I think its the way to go. Its just that I read somewhere that these RV thermostats can be adjusted on the inside as to how many degrees you want between the actual temperature and the temperature set on the tstat, the same as in the digital thermometers, that usually come set to an about 1 degree difference and you can adjust if so desired. The smaller the difference, the shorter cycles youll have. Bigger difference, longer cycles, less often.

Thanks for the responses. I appreciate your help

Art

[twe412]

I just looked it up on the RV maintenance book, the small lever inside the thermostat is called the "heat anticipator".
I guess Ill experiment some by adjusting it and see how it affects the propane consumption.

Thanks everyone

["007"]

Your therm also controls the AC/Heat pumps control boards in them you can find PFD's for which ever 4 or 5 button control in QT's 1 & 2.
So do not change out.

[twe412]

Thanks for the comment, 007.
Its not really giving me any real problems, it was just a matter of trying to save some propane in the long run. In the end, I did adjust the heat anticipator, and the cycles just got shorter and shorter (therefore, more frequent), which was even less efficient, so I just went back to the old setup. I might wait untill the summer to get the home thermostat, I have the old Penguin units without heat pump/strips (old gray digital thermostat) and a separate crappy thermostat for the furnace. Once I do the conversion to a Hunter thermostat for the A/C, Ill go ahead and wire the furnace to it.

Thanks everyone