HVAC blower trouble

[BearZDefect]

Our house has a Rheem heat pump, which is great at temperatures above 40f, but poor below 20f. But that is a sidetrack...

On these wintery days the heat pump runs nearly non-stop. It only gets to take a break in the late afternoon or early evening.

This afternoon I noticed the blower didn't start normally, it took too long to spin up. I hoped it was a fluke.

But it wasn't. The next time the HVAC stopped, when it restarted later the blower motor buzzed but wouldn't move. I turned down the thermostat so it would shut down.

I opened the side panels to find the blower. I could reach my hand in to give it a spin - it did not feel stiff at all.

Ten minutes later I restored the thermostat setting. Again the blower motor could not start. I opened the panel again, gave the blower a spin, and it started.

So, at least we are not completely without heat overnight, but this requires too much attention now. I cannot leave the house lest it burn out itself, or the heat exchanger from lack of airflow.

My questions are:

- Is this simply a worn-out motor? I can't see this being solved with lubrication.

- If the motor is bad, can it be replaced alone? I don't see how it can be removed without some significant disassembly of parts in front of it.

- I plan to call an HVAC outfit tomorrow morning. What should I expect from them?


TIA for your advice and input!

 

[Quest]

If your motor can spin freely and yet it took some time/effort (like manually sticking your finger into the grill to spin it, at the risk of getting your finger chopped off), most likely your controller module or your motor is bad.

You'll need to get all the details (model, type, etc. if you can gain deeper access to view the motor body to see what make/model and # of wiring, etc.) in order to diagnose further.

 

[tom slick]

The motor may need a new start capacitor. Fairly inexpensive fix.

 

[nazareth]

sounds like possibly could just be your run capacitor cheap easy fix just need to know the microfarad rating cost about 5 bucks.
if not the capacitor than most likely your motor

 

[BearZDefect]

Thanks, Quest.

There is one side panel on each of the two sections. Each has different info (like model #) on it.

The top section is the heat exchange.

The bottom section has the fan and some controller stuff.

I do not stick my fingers through a grill - this blower is like those in a car. I touch the treadmill blade through the center. When I shove it to start it still takes too long to spin up to normal speed, but if finally does. No risk of chopping my fingers at the rate it starts.

The control circuits seem to be fine, as in they are triggering the right devices. Only possibility I can think of there is if the controller is supposed to give the motor an extra something for startup.

 

[BearZDefect]

tom slick, nazareth, that sounds like a possibility. Let me look for that capacitor!

 

[Quest]

Yes, those good folks have a point too (so plse check to see if it's your motor capacitor).

Unfortunately, with new technology in-place, my Trane XV-95 variable speed AC motor doesn't come with capacitor anymore...

*sob*

Also: if your motor run capacitor is bad, you may hear an obvious "buzz" or hum from motor even though it's having difficulty to spin....check and see if you can hear that buzz..

 

[nazareth]

every single phase psc motor has either a run capacitor or run cap start cap combo. blower motors on a residential aplication will just have a run capacitor usually mounted on the blower wheel houseing close to the motor. .becareful sometimes they can hold a charge once you remove it short out the terminals

 

[edhackett]

I had the exact problem a few years back. It's the capacitor. The starting with the hand spin is the telling clue.

Ed

 

[nazareth]

variable speeds convert ac voltage to dc voltage to change the frequency shorter longer wavelengths to increase or decrease speed according to static pressure to compensate for duct restricitons. they dont use capacitors i doubt your rheem use this unless its a newer high efficient unit

 

[hatcoleman]

To get you by till the HVAC tech. arrives. I would suggest you set the fan to run continously. To do this on your wall thermostat you have fan button with auto & on. Turn it to on. The fan will run all the time. Even when the heat is not on. But you wont have to try and get it to start every time the heat comes on. I think you have a bad motor or run capacitor. To change the motor you simply remove the entire blower assembly. Probably two screws to remove. And the blower slides out. Then when you have the blower assembly out you can remove & replace the motor. This is a very common repair.

 

[BearZDefect]

Many thanks again!

I think I've found the capacitor. It is a metal can with a rounded rectangle cross section, about 2.5" tall, 2" wide, 1.x" deep.

Unfortunately I cannot read most of the writing on it. Only two lines in black are mostly legible but partly obstructed by the mounting. No tell-tale micro-farad symbols there.

I can power down the whole system, let the capacitor bleed down, then remove it. But it's too late to go buy a replacement, so I should wait for tomorrow morning to take it apart for further inspection.

hatcoleman, excellent suggestion, I will set it to have the fan always on for the night.

Unfortunately, the blower assembly cannot slide out past all the controller/breakers/wires in front of it. It would take a lot more work to remove it.


At this point, my next question is, what kind of store do I call for a replacement capacitor?

And I am curious how a capacitor helps an AC motor - I thought capacitors serve a boost/stabilizing function in DC circuits.

This blower is not variable speed in that it always runs at the same speed.

One more detail - this house is about ten years old, and the HVAC is whatever the builder contracted back then. It's an inexpensive house too.

 

[andyd]

The capacitor gives an AC motor an extra jolt to help start the motor.

 

[nazareth]

a cap basically creates a third phase. in a generic term. common blower caps are 10 mfd 12.5 mfd 15 mfd. some are 20mfd.i if you cant read what its mfd rating on it there would also be a lable on the motor sating the h.p. vlotage ect it should also tell you the mfd requirements but chances are youd have to remove the motor to read it . its usually covered by the belly band. i would probably go with a 12.5 mfd 440vac run cap. if you can find a decent ac guy he will probably sell you one and even test the one you have to see

 

[nazareth]

you can run the fan continuosly and just spin the blower wheel and get it going. wouldnt recommend this unless its a emergency. running a motor with a bad cap casues the motor to over amp which will cause the motor to overheat and can ruin your motor.

 

[BearZDefect]

nazareth, you are most helpful, thank you!

The blower runs almost non-stop these cold days anyway, so I may have to take my chances to not freeze the little ones tonight.

What appears to be the capacitor is plainly visible, but the writing on it is impossible to read.

The motor is farther in but peering in for some time with a flashlight I made out this info:

GE SKCP39HF R283 S

1/4 HP
825 rpm
208-230 V
2.0 A


Does that reveal anything new?

 

[Quest]

If memory serves, 1/4hp motor typically calls for a 5MFD (microFarads) 370~440VAC motor run capacitor. When purchasing make sure the following:

(1) it's for AC motor only and non-polar (non-polarised).
(2) the voltage rating is in AC only (and not DC)
(3) if oil type, make sure it's non-PCB (for GE: not "Pyranol" based dielectric oil filling).

Good luck!
Q.

*I'm enjoying all the experts advise on this subject already, even though I don't have a motor problem*

 

[tomcat27]

the capacitor give the motor an extra boost of power to get the motor spinning. I would check with a local motor distributor (Grainger ?) as they can likely help you choose what capacitor you need. there may even be some technical information available from GE on what capacitor is typically used with that motor.

 

[Jim 5]

Call a rheem dealer (from yellopages) with the model number and serial number for your heat pump. They can tell you which capacitor you need.

The 1/4 horse GE fan motor on my Carrier furnace failed on new year's eve day last year - that made it 6 years on 1 of 2 furnaces in the house. The GE dealer compared the armature/bearings on mine to the new factory motor and they were really loose comparatively. You'll never guess that the GE motors are made in mexico. They are small and wimpy with tiny bearings....barely adequate... just like every invisible-to-the-consumer component sold in north america today. [Rant over]

Expect yours to fail if it runs any amount of time.

 

[BearZDefect]

Jim, I am no fan of GE consumer products either. This blower motor has always a hum I don't like, I wouldn't mind replacing it if the replacement is better. But how can I be sure the replacement is better?

I do not mean that question to be rhetorical. I would like to know how to get a better blower motor, is such a thing exists for this setup.

And I have to consider the costs involved. Anyone have some approximate figures? I guess a local HVAC outfit should have some answers.