Central AC fan
#1

The fan (outside the house) on my central ac unit doesn't come on when the flip the switch to ON on my thermostat (inside the house). The blower on the furnace blows fairly cool air for a few minutes, then the air warms up again. Whats going on?
#2
If the fan is not running, it is not removing any heat, therefore the system is tripping out on high head pressure or compressor overload. It would be very difficult to pinpoint the problem positively without actually being there to test and see for myself, but it is likely that the problem is either the fan motor itself is burned out, or bad control relay. But there are also other components in the circuit that could be bad. Do not keep attempting to start the unit until it is repaired, it is very hard on the compressor to overload it.
#3
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Maybe it'd the starting capacitor for the fan motor .Remove the cover for access to the electrical connections and you may fine the schematic inside the cover. Go to an HVAC supply-house with the schematic and all unit info- make,model, serial #, etc. and they will advise you. The capacitor may have "push-on" connections. YOU MUST discharge the old capacitor by shorting across the connection terminals. You can get more expert advise on the "Heating & Cooling" section of the Forum.----Good Luck!!!
#6
Re: Central AC fan
Originally posted by GiveMeLight
The fan (outside the house) on my central ac unit doesn't come on when the flip the switch to ON on my thermostat (inside the house). The blower on the furnace blows fairly cool air for a few minutes, then the air warms up again. Whats going on?
The fan (outside the house) on my central ac unit doesn't come on when the flip the switch to ON on my thermostat (inside the house). The blower on the furnace blows fairly cool air for a few minutes, then the air warms up again. Whats going on?
The fan switch on your thermostat controls whether the air blower motor will run continuously or only when the AC/heat is running. Some people prefer to run their blower constantly to maintain an even temperature in the home. If you look at the switch you are talking about you will probably find that the other position is labeled "auto" meaning automatic with the blower coming on and off with the rest of the unit rather than being "ON" all the time.
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Tom