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Furnace - Short Constant Cycles (digital thermostat)

Posted: Wed Jan 14, 2009 7:44 am
by Teresa73
I read the manual I bought from Mark, and read the furnace section in the forums. So, I understand that the possible 'fix' for constant short furnace cycles, however when I took the cover panel off my digital thermostat on the wall - there was no sliding switch to adjust the numbers which would typically be the fix for my problem.

My question is does anyone know what to do when it's a digital thermostat and seems to be lacking the sliding switch to adjust those numbers? I checked the thermostats website, and they said the thermostat is obsolete. I could or should upgrade to a more modern one. Could being obsolete cause the problem, or should I try to go back to a manual (old fashioned non-digital) wall thermostat?

This constant turning on and off of the furnace is expensive (gas furnace) and driving me insane. It no sooner shuts off then BAM turns back on. :?

RE: Furnace - Short Constant Cycles (digital thermostat)

Posted: Wed Jan 14, 2009 8:25 am
by Yanita
Good morning Teresa,

I am going to move this to the heating forums. All questions related to heat and air are posted there.

Be sure to read the "posting tips" for that forum, you may need to include your furnace info and more info about the thermostat itself.

Thanks,

Yanita

RE: Furnace - Short Constant Cycles (digital thermostat)

Posted: Wed Jan 14, 2009 12:26 pm
by oldfart
Hmmm...furnace short cycling? Folks I thought I'd just chime in here with some of my rambling thoughts. During my remodel of my ca. 1970 home one of the upgrades I made was a new Honeywell thermostat. Now, mind you..this is a new (2007) thermostat on an old (1970) mobile home. Keep that in mind. It's not a digital/programable style thermostat. Just a new thermostat from Lowes....about $30 if I recall correct. Ancient.... Miller kerosene furnace..single-speed blower and all that. But puddy much trouble-free since I moved here in... '83....?? I like simple things. I can clean the furnace...replace the various parts and it still runs about 80% efficient. Them new furnaces? Computor controlled....need a doctorate in high-tech to work on them..still 80% efficient. Yup..they're safer due to the high-tech doo-dadds..but I cain't fix 'em. Anyways...installed the new Honeywell thermostat and the furnace cycles off and on....a lot. At first this bothered me until I figgered it out. The old thermostat I could just pluck off the wall and adjust the "rise and fall." What this means is the temp. inside the house could be adjusted to fall 3/5/7/10 degrees until the thermostat kicked on and called for heat. The new Honeywell..couldn't do it. No way to adjust the "rise and fall" temps. Hmmmm....? Well, I'm learning to adjust and here's some new thoughts on the matter. More to come of course....Audie..the Oldfart...

RE: Furnace - Short Constant Cycles (digital thermostat)

Posted: Wed Jan 14, 2009 12:43 pm
by oldfart
Well folks in my case...not all cases I'm sure..there is a benifit to the short-cycling. My new Honeywell thermostat maintains a fairly constant tempreture in my home rather than wait until the temp. falls so low the furnace has to run for a long period of time to correct for the loss of heat. In extant..the furnace can run for a sort period of time...often..or it can run for an extended period of time less frequently. Life is about trade-offs. Is one better than another? Perhaps. I've spent 20yrs. installing heat-pumps and A/C units and one of the first rules of heating and cooling it that it's easier to maintain tempreture than it is to change it. It's cheaper to keep a warm house warm by cycling the furnace on often... than it is to warm up a cold house. Same goes for cooling. Keeping a home cool is cheaper than cooling down a hot home. Mind ye...I'm not saying there isn't a problem if the furnace/A/C unit is constantly cycling. I'm just saying it's cheaper to maintain the temp. when it's possible. Audie..the Oldfart...

Posted: Wed Jan 14, 2009 1:37 pm
by flcruising
What is the model# of your thermostat? My Ritetemp is about 5-6 years old, and there's a setting for 'temp swing' that is not obvious on the interface. I didn't find the setting until LAST YEAR, (even then, I just stumbled upon it) because it bugged me how often our unit cycled too. Then I found the one-liner in the owners manual about how to change it...was obvious then I guess?

IOW, it might not be a manual dip switch or slider, it may actually be a button you push to access the temperature swing (simulated anticipator) setting.

RE: Furnace - Short Constant Cycles (digital thermostat)

Posted: Fri Jan 16, 2009 5:42 am
by Robert
Thanks Audie and Aaron, the joys of digital. Kinda like tv's, the newer ones have same characteristics, just have to walk down a different trail to access them.


Thanks,
Robert

RE: Furnace - Short Constant Cycles (digital thermostat)

Posted: Fri Jan 16, 2009 12:54 pm
by oldfart
Aye Robert..the joys of digital..ehh! Yesterday I was sittin' in the recliner rolling up some ciggerrets (to cheap to pay $45 a carton)..had all 3 remote controls sittin' on the snack tray next to me and that lousy cat pounced on the remotes! Excellent...just beautiful! I spent the next 3 hours trying to get the t.v. to work! Called Comcast and tried to explain..."NO...I am not paying for THAT movie...and what kind'a freaky movies ayre ye showing anyways??" O.K.....O.K....it took me a while to make the phone call..but I made my point! I remember when we had antennas and things that rotated to bring in a clear picture! Audie..the disgruntled Oldfart....;)

RE: Furnace - Short Constant Cycles (digital thermostat)

Posted: Fri Jan 16, 2009 1:35 pm
by Robert
Yep, me turning antenna and Dad yelling "a little more", "a little more".

Didn't matter if it was hot as blazes, cold as a---------------, raining, didn't matter.

I was the Dadficial tanner turner !!


You must be slacking, I got 5 remotes, LOL.


Take care and best wishes,
Robert

RE: Furnace - Short Constant Cycles (digital thermostat)

Posted: Wed May 06, 2009 6:02 am
by MayDix2009
Yeah the new Honeywell thermostat maintains a fairly constant temperature in my home rather than wait until the temperature falls so low the furnace has to run for a long period of time to correct for the loss of heat....



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