limit switch

[smartin1971]

hey guys..
this is a goofy one..when im home all day my furnace seems to run okay except the fact the booster motor sometimes stays running after the furnace shuts down.(if i tap on the furnace the booster motor shuts off) today i go home at lunch and the blower is running (cold air ) coming out..i found that my limit switch was tripped so i pushed the red button and the furnace ignited and ran a normal cycle just fine.( this does not happen when i am home) i cant figure that part out. anyway can you give me an any idea or clue what may be causing this..last year i replaced several parts and was working fine until now..please help i cant stay home everyday..

thank you very much

Scott Martin
COLEMAN FURNACE# DGAT095ADC

[DaleM]

You need to replace the combustion motor relay. Do you have an A-coil under this furnace? If so, are the coils clean? There's a reason the furnace limits out, usually it's from a lack of air flow. If the A-coil is dirty that would cause it to limit out.

[smartin1971]

Dale
yes there is an Acoil on this unit..i will check and clean them if needed..can you give me the part number for the reley i need...thanks again

scott

[smartin1971]

can you give me the part number for the booster realy...thanks again

[DaleM]

I dont know the part number. You can pull the relay and there will be a part number on the labeling of it.

[smartin1971]

will this be the one on the left or the right when looking at the furnace..thanks again

[DaleM]

Could be either one. Use the schematic and trace the wiring back from the combustion motor.

[smartin1971]

will do..thanks so much again