thermostat seams to be ok after jumping the circuit.
cleaned the sensor with steel wool.
took the "A" coil all the way out this time and completely cleaned it with a brush/shop vac/air compressor.
got my fingers crossed!!!!!

Make sure the flu is not clogged!!!!, snow up against it will shut off the furnace!! Limit switches will also go on & off.

no improvement:( :confused:
60° again this morning ning ning ning.

Your limit switch could be bad. I had to replace mine If the switch senses that there is to much temperature in the chamber it will shut down the heater like you are describing. Mine did it because the genious put in a heater that was to large and then died on me. I learned a lot about the electronics in them as the electronic parts went bad from a poor install. A limit swicth will get worse the more it gets tripped. You can buy this at your local heating and cooling supply house and it should not be to difficult to find on your unit. It is the same as a circuit breaker a breaker will get weak and trip easier the more it trips. Sorry you are freezing. I don't think our heaters have shut off all night.
Jeff will be able to help you more than me I just had to repair my own because it got to expenssive to have some one come out all of the time. I could not afford to replace the units all over again.

loto,

Time for me the exact time it RUNS as well as the exact time it is OFF. Wait for it to trip and time again, and finally once more. Get three accurate TIMES recorded and let me know exactly how many (minutes or seconds) for each.

Also, do you have a wiring diagram for that furnace? usually on the back of one of the doors. Can you snap a picture and post it?

If your furnace is running 8 minutes, that is usually a pretty good amount of run time. Usually a limit trips in a few minutes and then is off for the same amount of time until it cools.

Keep me posted, I am in the office right now and maybe can help.

Jeff

Also, as long as you are freezing your ass off, see if you can locate a model number or make of the furnace.

Trane
Lennox
Heil
Bryant
etc

Is it vented in PVC pipe? or vented in metal stove pipe?

Hell, just take a picture of it and post :eureka:

HP500,I was thinking the same thing but 15 years old I don't believe it would be a 90+, I've had problems with those when there is no pitch in the exaust and it ices up. Does exactly the same thing, short run cycle off a few and short run again

man o man its toasty in here:D :D :D

Bossman (Rich) walked me thru the entire trouble shooting process over a half dozen phone calls.
i cant thankyou enough Rich!!!!!!!

the problem all stemmed from a extremely dirty coil.
because it was so dirty , the furnace was getting hot very quickly and shutting off.
dummy me made the problem worse by closing off vents in parts of the house in order to try and heat the areas i was using. that created back presure which made the furnace overheat even more. another problem was the fan wasnt pushing enough air so Rich talked me thru switching some wires around to get a higher speed fan.
he also had me wire a jumper in so i get the high speed fan in winter and summer. the end result should be a less expensive utility bill , winter and summer!!!!! more gas money for the boat;)

ive already told Rich on the phone but ill do it here also.
if you ever want to take a trip down to LOTO you have a place to stay and the drinks are on me.

thankyou to everyone else who replied to the thread also!

now , back to your regularly scheduled program.
Apaches are better:D

loto, glad to hear you got it fixed.

Now get some of that beer out of the fridge and enjoy :)

I saw on your termostat that the fan was on auto. I would just leave it on. It helps prevent hot or cold spots in your house and keeps the air cleaner. You will need to change the filter every 30 days, unless you buy the real big high dollar ones.