/diy/ - Do It Yourself

Oh and how cool is it to watch the burners fire up on these things. People fucking around trying to get backyard foundries to work when they have what they are looking for right in their basement.

>>1571204
Mhm, does it only happen on the heating cycle? No peculiar noises I presume? That shit sounds like an ECM motor. If there's anything that fucking fails on those pieces of shit it's the motor module on the back

>>1571267
No it also happens if you just set it to circulate the air in the house. Fan runs normally for a few minutes and then starts struggling and slows down into a stall where there is loud buzzing.

Pic related is motor, looks like a regular induction motor to me.

>>1571331
That's what a bad run/start cap will do.
Same capacitance rating. You can use a higher voltage if the one you need isn't there.

>>1571366
You sure? I reassembled everything and did another run, it went for like 3-4x longer this time. The blower would make a screech and suddenly slow down every couple of minutes like the fan hit something; it made it until the burners finished their cycle and then it stalled right after.

>>1571412
Run windings can also fail and cause similar issues. You can try changing the speed up a tap and see what happens. The different windings are independent of each other so try another and see what happens to at least get you going. Otherwise a capacitor is like $5 to try.

>>1571412
Screeching = Bearing problem

>>1571416
I ordered the capacitor. In the meantime I guess I can try a different tap. So going by the wiring diagram and the motor label, I just need to swap out the orange wire for any one of the other 4 wires to try a different speed?

>>1571469
The black wire is already in use but you could go with blue or red. I'd try blue as it's closest to the current speed.

>>1571479
I did some heat cycles with the blue, runs ok. Seems to struggle a bit at times but no screeching noises. So I'm guessing bad start cap fried the med hi speed windings. I'll keep it off until the replacement cap comes in.

I could leave it on medium low speed afterwards but I'm concerned about damage to the heat exchanger from running too hot constantly.

Anyways thanks for the help guys.

test capacitor, easy to do.
if it's low, it's that.
though if the fan makes a hell of a noise when it runs, it just means the motor is failing/getting locked up. you could try and repair it but good luck. a whole new motor will be less than 100$ most likely.

>>1571521
In america maybe; I could walk down to the local home depot and choose from a bunch of generic replacements from what the website shows. In canada however the closest thing to furnace related parts they carry are filters.

I'm going to have to go to some hole in the wall repair shop with no online presence at all and pay through the nose for a replacement because of how little availability there is for stuff here.

>>1571536
literally just google. I've found several on amazon that will work, possibly. Depends on your current furnace size/wire connections and how much work you can correctly do.

I don't get why people I go to do repair calls for act like HVAC devices are magical and only come from the magical whole salers. Fucking everything is on amazon for the most part. I've ordered gas valves from it before that local places "couldn't get".

>>1571331
>Fan runs normally for a few minutes and then starts struggling and slows down into a stall where there is loud buzzing.
sounds like a failing bearing/bushing
once the rotor contacts the field it will stick tightly

>>1571536
That's hard to believe. You can get them at Grainger, and those are in canada. A new motor costs like 100 bucks, and they're pretty standard, just get one that's the same size.

I replaced mine recently. Tried changing the cap first, but that didn't fix it, bearings seemed OK. Not really sure why it didn't work properly, but whatever, they're cheap.

I got the cap and the highest speed is working normally now for ~7hrs, but the other speeds failed to start so motor is shot. I found a NIB craigslist motor which is almost the same but is rated 30rpm faster and 0.8 amps higher, anything to worry about or should the relays be able to handle a small difference?

>>1573221
30 rpm faster doesn't matter. The 0.8 amps is not significant enough to make a difference.

>>1571437
Yea.. they do wear out. OP should check for end play

>>1573301
>>1571437
>>1571552

Yeah I'm starting to think this since the stall behaviour has been so unpredictable. It ran fine until my last post; it started stalling near the end of heating cycles afterwards even on the high speed tap.

>>1573445
OP here with a follow up. I opened the motor and the front bearing oil had completely dried up and it was gummed up with crap. What a shit design; the 'bearing' was a simple steel bushing stuffed with some cotton like material to wick oil onto the shaft as it spins, but it wasn't sealed in any way so dirt and air just turned the oil to sludge.

I cleaned it out and soaked it in oil again and it sounds like a completely different motor now.

If you don't know what I'm talking about then see below, literally designed to fail.
https://youtu.be/gHVuTApqBDY?t=187

>>1571204
Every time I think I work with idiots I come here and read threads like this. You put waaaaay too much time into this dumb shit. Bearing is roasted, and despite what you did they are not supposed to be re-oiled. You should've just got a new motor and cap and replaced it, which you are going to have to do soon anyway when the motor you "fixed" smokes out.

Retards, retards everywhere

>>1574661
The motor is already toast, what's it matter if I keep it going? Especially since warm weather is almost here and I'll be able to take my time to source a cheaper replacement than what I found.

>they are not supposed to be re-oiled
No shit, they are supposed to be replaced with another motor designed to fail. If they had used real sealed bearings the motor would've lasted the life of the furnace.

>>1574788
>The motor is already toast, what's it matter if I keep it going?
My point was that you invested more time and effort into trying to half-ass back to life than if you'd just replaced it to begin with. If you were going to pull it all apart to try and oil it you should've just put a new one in, which you will end up having to do anyway soon.

>>1574798

nice parts changer mentality. if the bushings arent totally fubar you know as well as i do a little oil will bring them back to life for a reasonable amount of time.

or do you get upset seeing people save money by fixing things themselves

>>1574811
Christ you're dumb. I couldn't care less if you fix your own shit. If I came to your house on a service call there's no way I would charge you labor to take the entire blower apart just to lube a motor with sealed bearings that isn't meant to be lubed. Why? It's a waste of time to take it apart TWICE, and I know that any patch/temp fix won't last. The humorous part to me is watching a retard like you do all this extra work.

I bet you didn't even take the wheel out and wash it off either, did you?

>>1574820
>If I came to your house on a service call

I can picture it:
>20 year old van leaking fluids with a mountain dew can in the cup holder

>Steps out wearing boots with the steel toes showing

>Tosses a cigarette butt in my front yard

>Phone call from ex wife #2 about JR #3 getting suspended while on my time

>Blower motor is bad, you should change the whole furnace rather than fuck around with this thing

There's no reason to be such a dick to strangers on the internet. It's a DIY forum and it's up to OP if he wants to spend a couple hours kicking the can down the road. It has no effect on you.

>>1574905
Haha thats so accurate.

>>1574661
>they are not supposed to be re-oiled.
Most of the one's I replace have yellow plastic caps on the oil ports.
They failed because no one removed the caps and put a few drops of sae-20w in them each year.
My furnace is a 1980 model with the original blower motor. I put tubes in the oil ports instead of putting the caps on so I can re-oil it just by removing the access cover.
Yeah, it's not the most efficient furnace I could have if I replaced it but it also doesn't have all the electronic crap to make it die every few months.
I oil it once or twice a year and it just keeps going.

>>1574798
The first time I took it apart I was nervous about fucking it up and went slow because of the stigma around le scary furnace and gas appliances. Now I can have the fucking thing apart and the motor pulled out in under 5 minutes. I've rebuilt shitty lawnmower engines that had more parts and were more sophisticated than these things.

>>1574946
>but it also doesn't have all the electronic crap to make it die every few months.
This so much. The amount of money people are charging for a replacement ECM module will get you a regular synchronous motor and mainboard so you can unfuck your furnace into something that is reliable.

>>1575230
Good idea! Completely re-engineer the unit from its original configuration because you're too lazy and stupid to (a) maintain it so it doesn't fail and (b) properly service it if it does. So what if you void all the certifications on it by doing so?

It's retards like you that burn houses down and kill people and then blame the equipment manufacturer.

>>1575854
I think you're being overly dramatic, but this thread reminds me of a service call:

>buddy calls me, says wife is getting headaches when the heat runs
>go over with CO meter and take a look
>instant headache as soon as I walk in
>tell him open windows and doors
>CO meter goes bananas
>check furnace heat exchanger, massive cracks in it that have opened so wide I can put a finger through them
>its been overheating for YEARS
>furnace is grossly oversized and there's only a few duct runs on it
>it was a model with a one-shot fuse link on the limit that would kill the burners if it tripped and had to replaced (forcing you to go check what happened)
>previous homeowner was DIY asshole who put furnace in himself
>it had to be tripping the limit constantly so he "fixed" it by removing the fuse link and limit and replacing them with old style fan/limit that would automatically reset when it cooled
>he also bypassed control board and other safeties and re-wired it himself
>guy probably patted himself on the back for his genius
>meanwhile he almost killed two people with his ignorance
>all because he couldn't understand the "complicated" controls and was too cheap to call a professional to check it over

>>1575867
>>1575854
>>all because he couldn't understand the "complicated" controls and was too cheap to call a professional to check it over

Nothing complicated about shitty designs engineered to fail. The whole wiring interlock diagram is right on the front panel to allow the 'professional' monkey that gets paid to install it to be able to figure it out. Replace shitty ECM motor with a similarly rated syncronous one and install a mobo whose only job is to flip a relay, check the interlocks on the wiring diagram and count timeouts. Shit ain't rocket science.

My piece of shit furnace has a roll out switch that resets itself. It was probably overheating for most of this winter, but not enough to cause the actual soft lockout until the motor totally failed.

>>1574820

>calls a sleeve bearing a sealed bearing
>says you cant oil a sleeve bearing
>larping as an hvac tech

nice one

its called an oil wick for a reason, theyre absolutely oil-able. if you pulled your head out of your asshole you may realize this.