Gas and Oil Home Heating Furnaces - Outside blower fan not spinning

the outside fan is not spinning - i know that electricity is getting to the unit because it humms every couple of minuntes- any ideas? is the fan motor bad?

When the fan hums see if you can give the blades a push with a small stick the way they should spin.If it runs then its the fan capacitor. If not call a hvac tech to look at it . Be sure and turn the power off to the outdoor unit now.;) ED

i gave the fan a push and it works now!!! can i leave it running? what is the compacitor?

With the power off go inside the unit and find the fan capacitor and get a new one just like it and put it in . If the compressor was running to.. Yes you can leave it running "BUT BUT" the next time it starts you have to go out and push the fan blade again. After it cooled down I would turn the power off to the outside till you get it fixed.;) ED

My outside fan stopped spinning. I gave it a push and it still won't spin. What could be the cause? Where can I take voltage or ohm measurements?

dvasco
You didnt say if the compressor was running. If it is I would say get a new fan motor with a new capacitor.
to read or test for voltage you can get it right there at the contactor both the 220 and the 24. You amp out a unit to see what it draws if good or bad. You also amp out the fan motor and the compressor each by themselfs. To ohm something like the compressor.You have to pull all the wires off it and then ohm it to ground for a dead short or to see the ohms on each winding.
;) ED

I think the compressor is running. What can I do to confirm this. I do hear a something like a hum every once in a while. So I will replace the motor and capacitor.
I don't know what the contactor is. Can you tell me where to look up a schematic or diagram on the net.
Unfortunately, I don't have an amp probe for my Fluke.

Thank you Ed.

Before you do anything in the out door unit make sure the power is off. The contactor----- follow the 220volt wires that come into the unit they will go to the contactor. This is what the tstat pulls in with the 24 volts. So the24 volt wires will be there at the contactor also. As I said before If you dont have fan at the outdoor unit turn the power off to it now are you can lose a compressor . There should be a wire layout right there inside the unit;) ED

Ed, with the description of the contactor I now know what that is. I am better with electronic components than electrical. However, I didn't have to take readings. I still need to buy an amp probe.
Anyway, I tried pushing the fan again in the morning. I was able to get it to spin. When I called Trane for more info on the cap the salesperson confirmed it was bad due to the area of the contacts being domed rather than recessed. Even though I didn't now I could lose the compressor I turned off the AC and turned on the house fan. Hopefully the compressor is not damaged, the AC was on for about 4 or 5 hours before I finally turned it off.
Thanks guys for helping me out. The final cost ran me $35.

My outside condenser fan usually needed a "kick" start to get going, but then would keep spinning. It was usually a little stiff and tough to turn with a screwdriver, but kept going after a couple turns. Outside unit usually made a humming sound while fan was "stuck", but now unit is silent and fan won't spin on it's own but spins freely without resistence when pushed. When tstat is turned ON(cool), only hear a "klick" but no more humming sound. Any idea what happened or might be wrong? Any advice or instructions are greatly appreciated.

ET,
The humming you heard while the fan was stuck more than likely was the compressor running. If your unit shut down and you wasn't there to help the fan start back up the compressor ran without the fan which in turn either tripped the high head pressure switch or tripped the breaker, or blew a fuse in the outdoor disconnect if it has fuses. The head pressure switch "if your is equiped with one" may be located right where the copper lines go into the condensor unit or just inside the service panel. If you get this thing running don't let the repair of the fan go any longer beacause you will seriously damage the compressor. If you need to open the service panel or change a fuse shut off the power to it 1st at the breaker.

Matt, thanks for the advice. I was not able to locate a head pressure switch(would it be right on one of the copper pipes where it enters the unit?) The breaker in the breaker box in the house was not tripped. There is a "disconnect" box mounted on the outside of the house separate from the condenser unit which just has a big plastic "plug" that can be pulled out which has 4 heavy prongs on it that plug into the box. If the thing has fuses, would they be in this box or inside the service panel on condensor unit? I was able to get the whole thing(fan and compressor) running temporarily by pushing in a spring loaded button on the "contactor" in the service panel that has 4 heavy wires on it connected to 4 heavy screws, but when the button was released, everything would stop and the brass connector on the contactor would just pop-out and apparently break the circuit. Could prob be with the tstat? Thanks, Bob.

The thing you were pushing is the contactor and it is powered from a 24volt transformer normally housed in the furnace. You can check the t-stat by disconnecting it and jumping R-Y-and G together. If it runs the stat is your problem if not you've lost 24volts. Either transformer bit the dust, a fuse blew, or you're missing a saftey. Try turning it off completly at the t-stat and waiting a couple minutes then turn it back on.

You're getting close to needing a tech on this. Do you have a volt/ohm meter?

Nope....don't have a volt/ohm meter. How do I "jump" R Y G together? If a fuse blew, where would I find the fuse? Is it bad if I "lose 24v"? I really don't know much about HVAC or elec. but just like to play around.....however, it is starting to get a little warm inside. Thanks, Bob.

Does your indoor fan come on?

To jump the wires you have to remove the t-stat off the wall, unhook the three wires and twist them together.

It's a good idea to turn off the switch at the furnace prior to this.

Without the proper tools you should probly just call a good service tech.

The head pressure switch if not on the outside going into the condenssing unit it will be inside the condenssing unit. It will be attched directly to the small copper line with 2 wires coming out of it and should have a small button on it. Look around by the compressor.

Like Matt said you should have a volt/ohm meter to know whats what here.You said that when you push the cont by hand the fan and compressor came on. So you have the power there. Now its the 24 volt you have to find out.Like matt said. If you open the tstat in side you will see R Y G now get a small pice of wire and make a W out of it and put this wire on THE SCREW HEADS of the R Y G . If it runs then its the tstat. Does the inside fan come on now when you go to cool or just fan on?. Does the heat work now? this will tell us if the transformer is good;) ED

Ok, I found high head press. switch; a green plastic cap on the small copper line beside compressor with 2 blue wires coming from it: one to the connector box and one to impedence relay box according to diagram on inside of panel cover. No button on switch; just green cap with 2 blue wires coming from it. Indoor fan/blower has always worked, but when tstat switched to COOL, just a click on outside condensor(no fan turning, no compressor running)but indoor fan kept working. I took tstat off and connected R Y G with a wire and inside fan came on, nothing else; but when switched to COOL, just the CLICK on outside unit; no turning fan or running compressor. I don't have a furnace; just a heat pump. Should I still have turned off the switch on inside heat pump unit(if there is one) before jumping R Y G? Thanks.....I feel like I almost got this thing licked. At least I'm learning a little somethin'.

I still can't find any type of fuse if that's what blew and is keeping the compressor and fan from turning. Thanks for any info. you can provide.

I think you should get a volt/ohm meter like Matt and I have told you so you can ring this out If your going to keep working on it here.

Now you said R Y G connected The inside fan came on "good." We know now we have a transformer there . Now do we have 24 volt power at the contactor in the out door unit or not. You said you can push it in and all works ok. Now we have to find out if its the 24 volt power to it,or is the contactor bad and just wont pull in. Dont forget that thats 220 volt there in the out door unit when your working on it hot.You dont have a time delay in the outdoor unit unit there do you?;) ED

There is a time delay relay(Anti Short Cycle Timer) in the panel with 4 wires plugged into it. If I push the contactor button hard enough, I can get it to "stick" and everything runs; but if I just bump the whole unit, the little brass bar that makes the connection seems like it just barely comes off enough to make everything stop running. I'm supposed to be getting a volt/ohmeter from my neighbor, but he doesn't know how to use it. What, specifically do I need to test with the meter and how?

You know I think we are about to get this critter fixed. Lets ring out that time delay there.Could be thats what shuts you off from what you just said.

With the volt meter set for 24 volts ,only go on the "little wires" that would be comeing from the tstat. See that you have 24 volts at this timer from the ststat when it call's for cool then see if you get the 24 volts at the contactor from the timer.

"IF you think you can"and get it right + to+ and - to - With the tstat calling for cool, bypass that time delay with the 24 volts right over to the contactor and see if it pulls in. If it does you will have to get a new time delay for it..

Aways make sure you have the volt meter set for the voltage that you are going on 24 , 110 , or 220 or you will blow it up.;) ED

Ok, I replaced the whole contactor, time delay relay, and even the capacitor to make sure they weren't the problem and I still only hear the "click" when I turn the tstat on COOL. Everthing still runs when the contactor button is pushed. The time delay has 4 terminals and the only one coming from the house is tan. The yellow coming the house(and from the tstat I assume) goes to an "Impedence Relay" inside the service panel. There's an orange from the IMR to the time delay, but also a black from the timer to a circuit board which I think is the Integrated Defrost Control. Also a black from the circuit board to the timer. Any ideas what all these wires are for? I thought the timer would only have two terminals; one from tstat and one to contactor. Thanks for the help.

Well, I finally got this thing running; and it's actually starting to get a little cooler inside! Once I turned on the tstat to COOL, I had to wait a little while until everthing started running again, but the fan still needed a push to get turning and it was very stiff and difficult to turn with a screwdriver. When the power and fan motor were OFF, the fan could spin easily without resistence. Does this mean I need a new fan motor? When I had it all apart, I even put some fan oil in the oil fill holes in side of motor.

With a time delay there it will take a bit for the unit to come on after you call for cool. Also if the power goes off for a bit it will take a short time for the unit to come on. Thats how they work to save the compressor. Now fan motor You can try and just get a new capacitor for it and see if that will do it. If not get a new fan motor for it. The motor could have one dead field in it.;) ED

I followed this thread and my fan was not spinning. It started after I gave it a push and continues to spin.

Now, I want to replace the motor on the fan. Is there any suggestions on how to get this done? I am pretty handy and have done this kind of work (20 years or so ago before I went into the Army), and every now & then I undertake something like this.

Any suggestions would be appreciated.

It started after I gave it a push and continues to spin.

Look for the capacitor there for the fan and just get a new one .Should be all you need .

ED ;)