422 combustion motor starts very slowly

[woodauger]

The air intake is clear, the heater runs well after some initial yellow during startup. The combustion fan hums and runs quite slowly for the first two minutes, before getting up to speed. It is getting 117vac and measures 21 ohms. The bearings were lubricated this season, the pot was maintained also. Is my motor giving up?, or can the solenoid damper be slowing the blower down? Thanks again, gary

[rrob311]

My 422 combustion fan is slow on mine also. The bearings are also noisy. I think mine is ready to fail. I would put an amp clamp on it and if you have a scope you can view the waveform to see the condition of the motor itself. I am not sure if the motor has brushes that are replaceable but it would be worth checking.

[hawkins111]

If you have oiled the bearings and the motor is still slow, you are going to have to get a new motor. The new style will have ball bearings in it so you will be able to change them down the road.

[woodauger]

Thanks Tom. I checked my other heater, the fan turns by hand much easier than the slow one. Better now than in January. Is the motor exclusive to Monitor? If so, i have a dealer about 60 miles from here.

[hawkins111]

Yes the motor is built for Monitor. I did see two listed on EBAY for GF200, which are the same as M422. Check your dealers price before buying as Monitor parts are getting scarce and expensive these days. TOm

[woodauger]

The 'I'm stupid' light is lit above my head. I lubricated through the temperature reset plate opening on the side of the heater, and missed the second bearing cap on the back of the motor. all better for now - and I may go ahead and purchase the item from Ebay for a backup. Thank You, Gary

[rrob311]

Is it easy to oil the motor? Is there disassembly required?

[OnTheEdge]

Is it easy to oil the motor? Is there disassembly required?

I have 2 422 units and they have 2 different styles of bearings on the combustion motor. The older unit has a "packing" style bearing in the cap that can be oiled via small round black caps found on the housings. These style bearings left un serviced (oiled) typically just get dry and slow the motor (as is in the case of the OP) a few drops of machine oil every season is required for max life and performance..
The newer units have actual bearings and are prone to fail after years of use, there is no saving them once that start making noise..

Oiling/servicing the packing style bearings can be done without removing the combustion motor from the heater..

Changing the bearings on the other hand requires removing the combustion motor from the heater..

In the past I have cleaned and oiled bearings with great results, but to do so properly requires removing the bearing completely, and removing the dust shields from the bearings. Considering the cost of the new bearings and the time it takes to remove and clean the old ones for these units I would just replace them.

[hawkins111]

Where do you get the old style bearings?

Tom

[OnTheEdge]

Where do you get the old style bearings?

Tom

Tom, If this was intended for me.
I keep an eye on Craigslist, Letgo, and Offerup in my area, and have been able top pick up several machines for pretty cheap money, most of the time for under 100 bucks, and typically the machines just need some simple servicing and cleaning that the previous owners did not want to pay to have done. Just this summer I picked up 2 - 441's for under 200 bucks. Both needed the burn mats, and the fuel nozzles re attached. One also needed bearings on the combustion motor replaced and one of the rubber elbows on the combustion air supply to the burn chamber. I think I have around 50 bucks and 8 hours of my time into both units to get then running. In the past 2 years have accumulated enough spare parts to build 2 completely functional 441's and 2 completely functional 422's with enough leftovers to keep them in service for many many years.. Together with the burn mat and gasket material I got in bulk from McMaster Carr, there are very few if any parts I will ever need to buy for a very long time.. Currently I am using 1 of the 441's and 1 of the 422's to heat my house and the other 422 to heat my 16 x 30 shop.. This leaves me with a spare 441 to use as drop in replacement if/when the one in service goes down. I am still looking for another 422 to do the same thing..