furnace cycles

[muskyone]

i have a older carrier lp furnace that runs fine till it gets within 5 degrees of tstate setting then the burners go off then the fan. then it starts up agian right away if i turn it up to 90 it runs fine anyone please this is driveing me nuts

 

[Bob_VT]

Re: furnace cycles

When was the last service? Sometimes the eye needs to be replaced. Have it checked by a tech.

 

[roscoe]

Re: furnace cycles

How old is "older"? 10 years? 30 years?<br /><br />Did it just start doing this?<br /><br />Type of thermostat? old mercury bulb style or digital?<br />Dad's thermostat went bad a couple months ago. <br />Might try cleaning (vacuum or air blast) the thermostat, or replace thermostat, before opting for a $100 service call.

 

[craze1cars]

Re: furnace cycles

Is this a new-to-you house? Or any recent renovation that changed airflow in the home? Bad thermomstat location can cause this sort of thing.<br /><br />Bad locations: Near a register, near a window or door, near any heat generating appliance or light, on an outside wall.<br /><br />But if nothing has changed and this is a new problem that just popped up...location is proably not causing your problem.<br /><br />If the system hasn't been serviced within the year, it's time to call for a maintenance service call anyway. They can tell you exactly what it needs while they're there. If it has been serviced within the past year, just put a new thermostat on it to see if that's the problem...they're cheap.

 

[SS MAYFLOAT]

Re: furnace cycles

Sounds like the t-stat anticipator got out of adjustment or needs it. This part of the stat is to prevent over heating the desired setting. Pushing the temp up to 90 makes it real hard to overheat at that setting, so that is why it doesn't do it at that set temp. <br /><br />Thats my 2 cents worth....more info would help musky.

 

[muskyone]

Re: furnace cycles

it's in a garage new to me worked when it was taken out the stat is brand new a mounth ago furnace was made in the 80s i'm only home on the weekend and really don't want to pay a weekend service call on it stat is in the middle of a inside wall whats or were is the anticipator on can you adjust it thanks for the replys will ck agian when i get home getting sent to nebraska so i'll only be home every other weekend

 

[rickdb1boat]

Re: furnace cycles

If it's the mercury style T-stat, make sure the T-stat is mounted level first. This is the most common reason for your problem.

 

[heycods]

Re: furnace cycles

My carrier lp unit is 20+ years old it started that crap last spring. when I fired it up this fall it was still doing that. Changed thermostat, problem solved.

 

[SS MAYFLOAT]

Re: furnace cycles

The anticipator is inside the stat. About 7 years ago, I installed a brand new system including the stat. Unit kept cycling like yours. I read the paperwork for the stat, made the adjustment, and it worked fine after that. <br /><br />If your type stat does not have the adjustment for the anticipator, you should look for a new stat. How many wires goes to your stat. I'm thinking that it is 2 for yours. Good luck...