This furnace works sometimes and sometimes not. It will cycle 5 or so times and then the next time the fan wont come on and the limit will shut off the burner. I put a new Fan/Limit Switch in last year and this intermittent problem still exists. Can anyone tell me how to jumper the limit switch and give me any advise about other reasons the blower may not come on all the time? Thanks.
2006-12-04 11:13:32 · 5 answers · asked by bcbart82 1 in Home & Garden ➔ Maintenance & Repairs
I have no intentions of bypassing the limit switch. Its a combination Fan/Limit. I was told to jumper the "fan limit' to see if the fan would run any length of time or if it overheats. This was to eliminate possiblities. Thanks for the help.
2006-12-04 12:01:18 · update #1
Do not jumper any limit/safety switch ever. Find out why it is tripping. The limit switch is there to keep your house from burning down. You might have a clogged flue pipe . I would try that first. It could be the blower moter or the fan relay
2006-12-04 11:20:21 · answer #1 · answered by brian d 3 · 0⤊ 0⤋
DO NOT JUMP OUT THE LIMIT! UNLESS YOU WANT THE HOUSE TO BURN DOWN.
The symptoms sound like the run capacitor for the fan motor is shorted or the motor is bad.
If the motor seems to start up normally when cold, runs for a while and then gets real hot and shuts off, it is probably shutting down on its' internal limit.
If you have an electrical meter, disconnect the capacitor, short the terminals on it with a screwdriver, set the meter to OHMS or Resistance. Touch the capacitor with the meter leads. If the resistance goes up and stays up, it is shorted.
If it goes up and then slowly goes down, it is probably OK.
If it doesn't read anything, it's open. They're less than $10 at a wholesale supply house, maybe more at an appliance store.
If that's not it, the motor is bad if there is voltage to it when it shuts down.
DO NOT JUMP THE LIMIT SWITCH.
2006-12-04 11:23:27 · answer #2 · answered by Obsean 5 · 0⤊ 0⤋
Ok we both know it is not the limit switch. They are very easy to jump out. It is only a limit so it is either made or not. Putting the leads together will jump it out. It sounds to me the problem lies in the motor. The windings are going bad and the motor is overheating. It could be a bad bearing and causing the motor to go out on overload protection. You need to replace the motor and capacitor. Grainger is the best place to get one. Give the the model number off the nameplate. Be sure to get a new capacitor. They are about $10. If you decide to jump out the limit be sure to put the leads back on when you finish.
2006-12-04 12:21:04 · answer #3 · answered by skinnyrich_99 2 · 0⤊ 0⤋
Limit switch jumper--- blower cuts out ----- best advice that you will ever get is call the a/c company and get someone that is qualified and will properly save you from having a burned down house... this is not something to "jump" around with at all.........
2006-12-04 11:26:07 · answer #4 · answered by XTX 7 · 0⤊ 0⤋
Your fan motor is going bad. The motor has a bad spot in it and if it stops on this spot is why it will not start somtimes
2006-12-04 11:17:22 · answer #5 · answered by aussie 6 · 0⤊ 0⤋