5 year burn chamber rebuild update

[hawkins111]

5-4 CLEANING THE BURN CHAMBER & BURNER
POT
Under normal running conditions, soot will not
deposit in great quantities inside the burner, and a
light covering of soot will not affect the performance
of the unit thus it need not be cleaned. However, if
heavy soot built up does occur the unit should be
opened and cleaned.
The burner is assembled using gaskets to maintain
its air tightness. If these gaskets leak, the extra air
can cause a serious soot problem and or exhaust
gases to escape into the area being heated.
NOTE: If any gaskets are torn when components
are removed, replace. Disconnect power
supply to unit.
If cleaning is necessary, use the following method:
1. On the Monitor 422
A. Remove louver assembly.
B. Remove front cover.
C. Remove top cover and lead wire con-
nectors.
D. Remove front and top heat shields that
cover the bum chamber and their lead
connectors.
E. Remove fuel piping from burn chamber.
F. Remove igniter.
G. Remove flame detective rod lead from PCB
(DO NOT REMOVE FROM BURN CHAMBER).
H. Remove screw at top of burner cap which
attached it to cabinet. Remove screw at
back of cabinet from exhaust duct and
remove the 4 screws holding the burn
chamber to base.
I. Rock chamber back and forth lightly, raise
about 1/2" and remove burn chamber and
heat exchanger, as one assembly from unit.
J. Set chamber upside down and remove the
4 screws which secure the burner pot to
the burn chamber. Pull the burner pot up and
out.


MONITOR HEATINGSYSTEMS
Section 5: Servicing
3 Turn counter-clockwise to remove combustion
ring. If ring does not turn, pull up slightly to
loosen retaining clips.
4. Use wire brush to clean inside of combustion
chamber.
Vacuum and wipe clean with a waste cloth.
5. If tar is present on the burner bottom, remove
the tar by using a flat-bladed screw driver or
wire brush.then clean the area by using a
vacuum cleaner etc.
NOTE: Make sure all air inlet openings are clear.
6. When cleaning the inside of the burner pot,
remove the igniter and change the burner cloth by
the following procedure.
7 On the Monitor 422
A. Apply glue<P No8217) on the burner bottom

Put the burner cloth on the burner bottom,
afterwards press and straighten out the
burner cloth so that it is glued flat and even
on the burner bottom.
9. Combustion ring may deform and deteriorate
after several years use and should be cleaned
and inspected before reinstallation. If combus-
tion ring is warped, has cracked or is deteriorat-
ing it should be replaced.
10. When reassembling the unit check that com-
bustion ring is positioned with the correct side
up and is sitting squarely on all three support
screws(M~422) or pins(M-441) inside the burner
pot.
11. Reassemble by reversing the procedure foll-
owed during disassembly.
NOTE: Use of the economy plus feature can
minimize service calls and extend com-
ponent life.

[FordMan59]

Tom, I no longer have the manual. I lost it when my old computer went bad and it was on it's hard drive. Please post anything that will be helpful but not something I have to download because the small hard drive on the current computer is full.

[hawkins111]

Fordman,

I believe you have the Monitor 441/422 manual. Section 5 Servicing, page 39 has the procedure for disassembly of the unit. If you no longer have the manual, I can outline the procedure for you when you are ready.

I do wish you the best of health,

Tom

[FordMan59]

Fordman, Did you get your M422 serviced? I sent you a Private Message. If you're still having trouble post again here.

Thanks, Tom

No I haven't serviced it yet. At this point without a better understanding of how to remove the burn chamber and heat exchanger I think it's best I leave it alone until my mind (depression and anxiety) has improved). I'll have to look at your PM to see if it helps. I saw one from you a couple weeks ago but I still don't remember how to remove all the parts to access the chamber/exchanger and get it back together right.
.

[hawkins111]

Fordman, Did you get your M422 serviced? I sent you a Private Message. If you're still having trouble post again here.

Thanks, Tom

[hawkins111]

Fordman59, I sent you a Private Message.

[FordMan59]

NEW POST 4/24/2025

Been several years since I had the 422 apart and have forgotten the steps to removing the burn chamber. Can someone please give a step by step? Ever since my wife passed away I'm having lots of depression/anxiety issues and memory is just about shot. Any help is greatly appreciated. I thought pictures might also help. I thought I knew how to disassemble it but once I started I quickly realized I have totally forgot what has to be removed and in what order to access and remove the burn chamber. I took the top off ended up putting it back on because nothing looked familiar and didn't want to get it disassembled and not remember how it went back together.

[FordMan59]

As mentioned in this thread my flame ring in my 422 was welded around the circumference after 6 years of use. In January it will have been an additional 4 years since it was welded and still seems to be in good condition. Unless problems arise that cause the heater to lockout I won't be removing the flame ring for inspection. The current burn mat made with McMaster-Carr material 9323K21 will also be 4 years in service next month.

[wjcroft]

Tom, thanks. So what the cutting of the flame sensor rod does, is to make it less confused by a warped burner ring? It still detects flame even if the ring top has mushroomed significantly? Perhaps Monitor designed the sensor to detect deformed burner rings, because they are operating at less efficiency than unwarped rings? Still if any maintenance operation can be done that prolongs refurbish intervals, that pays for itself in labor hours.

William Croft
Mount Shasta

[hawkins111]

The other thing you can do to extend the time between overhaul is to cut off the last bend of the flame sensor. That's the last bend that makes the sensor go straight down. That little bit removed from the sensor will not affect it's operation. It will however get the sensor away from the edge of the burner ring. This is not a guess here, this has been done by just about everybody that has serviced a Monitor here in western Alaska for almost 20 years. If you look at Toyo flame sensors you can see that the rod does not have to be right between the wall of the burner and the ring, it can be above the ring a little and still be in the flame. Tom

[FordMan59]

I the last years of my stove business I would use burner mat cement to make the seam on the M422 burner ring smooth. The rings would last for quit a while before mushrooming out and causing a bad flame. One thing I did have to do was drill a hole in the top on the ring to relieve any pressure build up due to a sealed top piece on the ring.
If there is a problem you will notice the flame moving around. If there is a problem it is very noticeable.

I've checked the flame several times since I put mine back in service. Pretty blue flame, no signs of soot, or the flame dancing around. I'll keep your reply in mind. If I ever have a problem with the flame I'll remove the chamber and drill a small hole in the top of the dome. I figure the dome shouldn't mushroom out unless the welds break.

[hawkins111]

In the last years of my stove business I would use burner mat cement to make the seam on the M422 burner ring smooth. I did have some success with that idea. The rings would last for quit a while before mushrooming out and causing a bad flame. One thing I did have to do was drill a hole in the top on the ring to relieve any pressure build up due to a sealed top piece on the ring. If there is a problem you will notice the flame moving around. If there is a problem it is very noticeable.

[FordMan59]

I am interested on how you had the ring welded. Did you remove any material or add any?

I just had them leave the existing welds where the dome of the flame ring is welded to the bottom portion of the ring and had them continue the weld from one weld to the next until the dome was welded all around the circumference. I also had them hit the clips that hold the ring in the pot so that it won't be as likely to come loose. Once everything was welded I had them take a grinder and grind the new welds down to the same elevation as the original welds so I'd be sure they didn't make contact with the flame rod. The ring has been back in service now for about 4 days and no problems.

[rrob311]

I am interested on how you had the ring welded. Did you remove any material or add any?

[FordMan59]

I just put this heater back in service 1/17/19 with a new mat and having the flame ring welded all the way around. The heater had been out of service for the last year since I installed the new mat. If/when I have to remove the chamber again I'll give another update on how the mat/gaskets/flame ring are holding up. This ring had already been in service 6 years when I got it welded and reinstalled.