Rebuilt 422 Problems

[Maine]

Hi everyone,

I have replaced the burn pot, flame ring and all gaskets on my 422 and now the unit works fine, however my flame is yellow not blue.

Are there adjustments that I need to make?

The air chamber is not dirty or blocked.

Thanks for the help.

-John

[HayZee518]

reasons for no blue flame is not enough combustion air. look to the pipe going through the wall. clean out any spider webs in there. you might try to remove the flex pipe going to the combustion blower and remove the restrictor ring that is in there. don't throw it out! lastly the bearings may be shot on the blower motor 608Z bearings. While you have the blower out look at the damper solenoid. the small O ring may have cracked and restricts the travel of the damper solenoid.

[Maine]

Thanks for the reply. I actually unhooked the unit from the wall and it ran the same way- so if the yellow flame problem is only caused by lack of air I would say that I have an issue inside the inlet or the damper?

Thanks again

[HayZee518]

one way to verify air flow is to use a shop vac in reverse and blow air through the combustion blower and see what happens to the flame. the increase in air flow will make the blower's speed increase a little but will also blow more air into the combustion pot. the flame color should change.

[Maine]

Thanks again I will give it a try.

Do you suppose this (lack of air- dirty flame) was the reason for requiring the rebuild? The unit is my fathers and he doesn't exactly maintain anything.

[HayZee518]

if the unit don't work at all or works poorly then a rebuild is in order. blower bearings amounts to insufficient combustion air which soots up the viewing window and the inside of the combustion pot. the normal 97% efficiency goes way down and the chance the flamerod doesn't detect a flame or shorts out completely increases dramatically. these heaters have been around for 20 years plus, but if you don't maintain them they won't be reliable.

[Maine]

I understand. What is a general maintenance procedure for these units?

I have an M41 and it has been bulletproof, no work has been done to it for almost 10 years.

This 422 is only 5 years old and needed a total rebuild.

[HayZee518]

nelson & small is the mpi dealership in maine.

[Maine]

Thank you.

Is there any sort of maintenance schedule for these units?

[HayZee518]

the only real maintenance is to vacuum off or blow air over the heat exchanger fins to remove dust, which will stink up the house. clean off the fan blades, clean the sump filter screen, eventually you may need to change the combustion blower's bearings -608Z sealed bearings. Everything else is enclosed within the combustion pot.

[Maine]

Sounds good, thank you again.

I will investigate the yellow flame issue this weekend and report back, do the fan blower bearings typically wear out within 5 years or so?

[HayZee518]

I don't know of any presidence when they do wear out. For sure they won't last forever!

[Maine]

Just took the blower apart and verified that no blockages exist, the flame is yellow and I really didnt get a chance to run a blower on the intake.

Should I just assume the blower is bad and replace the bearing?

[Maine]

I would post a photo but it doesnt allow me to yet.

[hawkins111]

bad flame

Maine,

All Monitor 22"s and some of the first M422 blower motors have bronze bearing. If you look at the cap on the back of the motor and see a little black rubber cover you can oil the bushing. This may help you get the motor up to speed. If this gets no results I would make sure you have the Air Damper in place. This is the damper you can remove and should be marked Standard. It is a very important part of the system. Not in place the flame will be very strong and yellow. If the damper is in place I would think you will need to explore the Solenoid Damper on the blower case. If the "O" ring is broken it can block the damper and not allow it to open all the way.

Keep us posted,

Tom