GE FAN CONTROL 3AHL8C2A3 can't find? SHORT CYCLES

[keith0]

I have an old! G.E. mod. 21LD08CE9B2 Gas furnace that SHORT CYCLES runs about 4 sec. & shuts down NO AC! this most likely is the FAN CONTROL?? RIGHT?? Any help or where to find this old switch would be appreciated greatly!! Keith in hot tornado alley KS

[HayZee518]

short cycling is due to a heat anticipator not adjusted properly on the thermostat or not functioning at all. it can also mean a Cd eye being dirty or old and needs replacement. a thermocouple that isn't working could give intermittent results too. the fan control works with the fan not the burner control. the solenoid(s) on the main valve could be "going" too or the return spring inside the valve's core could be weak or broken. I'm still gonna search for the control. the AH in the number may mean Arrow-Hart instead of GE. It may be an Allis-Chalmers number too.

[keith0]

So this being the -(AC SHORT CYCLING) will all the mentioned item's have the same results on AIR CONDITIONING as they do w/HEAT?- Heat anticipator?,thermo-coupler?,solenoid?.. Cd eye is? sorry not my expertise. I replaced the THERMOSTAT w/digital type end of last season, maybe I got a bad one? Thanks Keith

[HayZee518]

the thermostat functions the same as drop in temp - turn on for heat. Increase in temp turn on a/c. three things must happen for the a/c to work. condenser fan turns on, compressor turns on and air handler turns on. a freon leak will frost up the compressor suction line, a freon leak would result in the hi pressure limit tripping. low freon would pump all the freon in the suction line and would trip on low pressure. if there is a sight glass in your system you should be able to see liquid flow in it with no bubbles. there's a green dot in the middle that changes color in the presence of liquid freon.