Central AC fan not spinning
#1
04-02-17, 03:41 PM
Central AC fan not spinning
Hi all,
Today I noticed that when my central AC runs, the fan does not spin (though I hear the compressor) and it gets quite warm (so I turn it off). I Google'd around and saw that the capacitor is a common problem here so I tried the "stick test" to see if I could kick start it but that didn't work.
Everything I found online stops debugging at the stick test. If manually spinning the fan fails, what else could it be?
Today I noticed that when my central AC runs, the fan does not spin (though I hear the compressor) and it gets quite warm (so I turn it off). I Google'd around and saw that the capacitor is a common problem here so I tried the "stick test" to see if I could kick start it but that didn't work.
Everything I found online stops debugging at the stick test. If manually spinning the fan fails, what else could it be?
#2
04-02-17, 03:47 PM
Member
It's still possible that the capacitor is bad, although it's equally likely that the fan motor itself is bad. If you have a multimeter, you could check to see that the fan motor is getting voltage. Since the compressor is running, it's unlikely that it's a power problem, but it only takes a minute to check it. Does the motor turn freely (not binding)? If it's binding (turns hard), then the motor is very likely the problem. Capacitors are relatively inexpensive, so you may want to try replacing the capacitor if the motor turns freely.
#3
04-02-17, 03:54 PM
Thanks for the reply. The blades turn easily and I don't hear any grinding while manually spinning them. Though while it's running it does get quite warm and I do smell a faint burning smell so I've ensured it's turned off.
Does this still mean it's likely the capacitor since the blades spin easily, just not on their own (even with the stick test)?
EDIT: I've also ready of some sort of reset switch but I don't see one. What might indicate that it needs a reset?
Does this still mean it's likely the capacitor since the blades spin easily, just not on their own (even with the stick test)?
EDIT: I've also ready of some sort of reset switch but I don't see one. What might indicate that it needs a reset?
#4
04-02-17, 04:05 PM
Member
If the motor passes the "stick test", then it's almost assuredly the capacitor that's bad. If it fails the stick test as yours did, it's probably the motor that's bad. However, there's a slim chance that the capacitor is the problem. Since a new capacitor is a fraction of the cost of a new motor, you may want to take a gamble and try a new capacitor to see if that solves the problem.
I assume that you're referring to a high pressure reset switch. Some units have them. They shutdown the system if the line pressure exceeds a certain psi. However, if your system has one and if it had "tripped", the compressor wouldn't turn on, so that's not your problem.
I assume that you're referring to a high pressure reset switch. Some units have them. They shutdown the system if the line pressure exceeds a certain psi. However, if your system has one and if it had "tripped", the compressor wouldn't turn on, so that's not your problem.
#5
04-02-17, 04:09 PM
Group Moderator
Welcome to the forums.
I too would agree it's a defective motor.
You said "central A/C" and posted in the A/C forums so we can assume it's not a heat pump.... correct ??
I too would agree it's a defective motor.
You said "central A/C" and posted in the A/C forums so we can assume it's not a heat pump.... correct ??
#6
04-02-17, 04:25 PM
Thank you guys again for the responses.
Yes, this is a central AC unit so there shouldn't be a heat pump, at least I don't think so.
The capacitor looks like something I might be able to do but the motor replacement looks a little out of my ability. About how much does it cost to hire someone to replace the motor?
Is there any chance that the entire AC unit must be replaced? It is old but up until this past season it's been working fine and the compressor still runs (which I know is the heart of the unit). I'm a little worried if I call someone out they will tell me I must replace the entire unit for thousands of dollars.
Yes, this is a central AC unit so there shouldn't be a heat pump, at least I don't think so.
The capacitor looks like something I might be able to do but the motor replacement looks a little out of my ability. About how much does it cost to hire someone to replace the motor?
Is there any chance that the entire AC unit must be replaced? It is old but up until this past season it's been working fine and the compressor still runs (which I know is the heart of the unit). I'm a little worried if I call someone out they will tell me I must replace the entire unit for thousands of dollars.
#7
04-02-17, 05:27 PM
Group Moderator
Without a make and model number it will be difficult to provide pricing.
A condensor motor could run $85-$200. Maybe $150-$200 in labor.
A condensor motor could run $85-$200. Maybe $150-$200 in labor.
#8
04-02-17, 06:31 PM
It's a Heil with model number CA1048QKA1 - I think. The sticker on the unit is very faded so I can't be 100% sure on the number. The date on it is something from the 90s but again, unfortunately the sticker is very faded so I can't make it out.
One other strange thing my wife told me - earlier she said she heard the AC unit making some noise and trying to spin the fan blades. She said she saw them spinning a little and then stop and this kept repeating. That is very strange as only the heat is on and even if the AC was on, the temp on the thermostat wouldn't trigger it. When I took a look at it later on, I was manually triggering it by lowering the thermostat and turning the AC on and that's when I heard the compressor as normal but no fan was spinning.
One other strange thing my wife told me - earlier she said she heard the AC unit making some noise and trying to spin the fan blades. She said she saw them spinning a little and then stop and this kept repeating. That is very strange as only the heat is on and even if the AC was on, the temp on the thermostat wouldn't trigger it. When I took a look at it later on, I was manually triggering it by lowering the thermostat and turning the AC on and that's when I heard the compressor as normal but no fan was spinning.
#9
04-02-17, 07:17 PM
Member
I'd start by checking voltage and capacitance. You will be working with live high voltage to do this, and will need to have and know how to use a meter.
