Author Topic: any heating experts? (broken furnace blower) (Read 6361 times)

Ukraine Train · « **on:** December 07, 2006, 02:42:47 PM »

My girlfriend has a York furnace, the house was built in '89 and I think it's the original furnace. The problem is when the blower motor gets the signal to turn on it just makes a buzzing sound and doesn't spin. Everything else works, gas turns on and lights, thermostat, etc. If I spin the fan by hand it turns smoothly so the bearings are fine. If I spin the fan while the motor is buzzing then it'll spin up and work fine until it shuts off and tries to restart. For now I just left the fan setting on ON instead of AUTO so she can get heat upstairs. I thought the capacitor on the motor was blown out so I replaced it with a new one but the problem didn't go away. That's the extent of my HVAC skills lol. The wiring diagram for the motor shows a low, medium, and high input. Low is not connected. Could it be a problem with the medium or high circuit? I can hear the relay clicking for high. I forgot my voltmeter at home and couldn't check if medium and/or high are getting power. Here's the schematic for it (big picture): http://fabiens.org/gallery/d/8450-1/IMG_0700.JPG

K Frame · « **Reply #1 on:** December 07, 2006, 03:49:43 PM »

Go to this forum: http://www.handymanwire.com/ubbthreads/postlist.php?Cat=0&Board=UBB7

And ask Harold. He does a lot of work with York.

280plus · « **Reply #2 on:** December 07, 2006, 04:08:58 PM »

Sorry to say but the motor is shot. Even though the bearings seem ok they are probably worn. To test, turn the motor back off and grab the motor shaft and try moving it side to side. Any play at all ACROSS it's axis will cause what you are describing. Sometimes it will feel like a click. The capacitor is not a total loss as it should be replaced with the motor anyways. Make sure you tell the repairman that it's new. I'll guess your looking at $400-$500.

Ukraine Train · « **Reply #3 on:** December 07, 2006, 04:15:09 PM »

Bah, repairman? It's six screws and four wires, I think I can handle it lol. I just need to find a replacement. Thanks for the help.

280plus · « **Reply #4 on:** December 07, 2006, 04:27:13 PM »

Not a problem, try Graingers. The tough part with those is getting the old shaft out of the fan blade without destroying the blade. Remove the set screw(s), clean the exposed part of the shaft with emory cloth, put penetrating oil around the hub and in the set screw hole. Let it soak for a while and then take an adjustable wrench and size it to the shaft so the flat is held by one side of the wrench or the other. Grasp the fan blade gently with your free hand and try to rotate it while holding the shaft still with the wrench. Or try to turn the shaft with the wrench. Do your best to not mar the shaft with the wrench. If you do clean it up with the emory cloth or it will jam in the blade. Normally they will break free pretty easily and once they do you work the blade back and forth while trying to pull the motor out. I've found it helps to turn the assembly so the motor is down and let the weight of the motor help you pull it out of the blade. If it gets to the point where you can't hold the shaft with the wrench anymore but the shaft is still too tight to slide out take you a big flat bladed screwdriver and a hammer. Stick the screwdriver into a hole in the back of the motor, wdge it between the armature and the frame that holds the windings and pound it in with the hammer. The object is to jam the armature so you can spin the whole motor and the armature will spin with it. Make sure your rotation is correct when you are done. The little curved blades "scoop" the air towards the opening in the fan housing. That's how I remember which way it goes. GOOD LUCK!!

Brad Johnson · « **Reply #5 on:** December 08, 2006, 08:10:21 AM »

Sounds like the start capacitor. I know you said you replaced it, but did you replace the capacitor for the main blower or the exhaust assist blower?

Brad

Ukraine Train · « **Reply #6 on:** December 08, 2006, 09:14:02 AM »

I replaced the one on the blower motor. It's mounted right on the side and the wires clearly go to it. I'm thinking it's the start windings on the motor.

280plus · « **Reply #7 on:** December 08, 2006, 12:24:46 PM »

Ohm them out. grin

Brad Johnson · « **Reply #8 on:** December 08, 2006, 12:52:44 PM »

Quote

Ohm them out.

"ooohmmmmmmmmmm...."

"ooohmmmmmmmmmm...."

"imagine the fan turning, like the breezes through the palms on a sunny seashore..."

"ooohmmmmmmmmmm...."

Harold Tuttle · « **Reply #9 on:** December 08, 2006, 01:38:17 PM »

ooooohm
ooooohm out of range

where the beer
and the capacitance stay

280plus · « **Reply #10 on:** December 08, 2006, 05:20:06 PM »

You guys are losing it. cheesy

Brad Johnson · « **Reply #11 on:** December 11, 2006, 08:39:11 AM »

Quote from: 280plus on December 08, 2006, 04:20:06 PM

You guys are losing it. cheesy

"Losing it" implies that you "had it" to begin with.

grin

Brad

280plus · « **Reply #12 on:** December 11, 2006, 08:49:23 AM »

Ukraine Train · « **Reply #13 on:** December 14, 2006, 03:18:31 AM »

So I finally got a DVOM on it last night. The startup windings have an open. Everything else is good, hi-med-lo had a resistance of about 5, 7, and 9 Ohms, respectively. There is 120v at the relay hi speed output. I'm still not sure when medium gets power, I got 0v at that wire. Anyway, would it be possible to repair the start windings? I wonder if it could just be a broken wire. Or is it more likely that it's toast? I also had the motor out to get part numbers and the fan came off the shaft without any problems. Loosened the set screw and it slid right off.

280plus · « **Reply #14 on:** December 14, 2006, 03:48:13 AM »

Quote

the fan came off the shaft without any problems. Loosened the set screw and it slid right off.

Figures, just count your blessings. angel

Would I personally try to repair or recommend that you try to repair that? Not a chance. I'm not saying you couldn't possibly figure out a way but are you going to go through all the trouble of taking it all apart and putting it back together just to find out it's gonna maybe not work at all or burn up again in 2 months and give up the ghost when you need it the most? Find your closest Grainger's. They've got all kinds of motors, you can even buy the cheap one although the expensive one IS the better choice.

Ukraine Train · « **Reply #15 on:** December 14, 2006, 04:00:45 AM »

Finding a replacement motor was a pain. Its an Emerson motor but apparently it was built exclusively for York so I have to go through a York distributor to get it. Except they cant sell it to me because Im not a licensed contractor. So, I have to go through a York repair shop and its $230 to get it through them. I found a place that sells Fasco motors for $150, and they said they have replacements for York furnaces, so I might get theirs. I dont know if I can just get a generic replacement from Grainger because it uses one of those three bracket flex mounts to absorb vibration and they dont seem to be that common from what Ive seen.

Ron · « **Reply #16 on:** December 14, 2006, 04:04:13 AM »

I would be real surprised if Grainger didn't have a replacement motor. They also sell universal mounting brackets.

A Fasco motor would be fine also.

Ukraine Train · « **Reply #17 on:** December 14, 2006, 04:10:03 AM »

Yeah, I was just thinking maybe they have an add-on bracket I could get. Looks like Grainger has motors with the same specs for like $80, just without the mount. There's a store not far from here, I might just pull the motor out and go down there with it.

280plus · « **Reply #18 on:** December 14, 2006, 11:30:24 AM »

We call it a "belly band". Yup, York is a pain, as long as they have the HP and/or amperage on theri you'll be OK. Sometimes they leave it off the label so it makes it real hard to use anything but their motors.

Ukraine Train · « **Reply #19 on:** December 21, 2006, 06:23:40 PM »

Well, finally got it fixed. I got a universal GE motor and a belly band for $160 and swapped 'er out. Thanks for everyone's help.

280plus · « **Reply #20 on:** December 22, 2006, 01:47:01 AM »

Next blower motor repair I get, I'm calling you! grin

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Author Topic: any heating experts? (broken furnace blower) (Read 6361 times)

Ron