Monitor 422 - yellow flame, then error codes

[catamount]

My Monitor 422 has slowly gone from a nice even blue flame to an uneven yellow fame. I've noticed that the heat output really decreased over the past year as well.

Now, it has started shutting off after the first 5 minutes of burn. It will fire up, but after a few minutes of yellow flame the burner shuts off and the error code appears.

1) Does anyone have any ideas as to the main culprit here?

2) I know I'll need a service manual to disassemble this thing. Is there anyone who can email it to me? I'd be happy to PM my email address to anyone who can help.

Thanks!

[hawkins111]

M422 overhaul

You need to overhaul the burner. New mat, ring and any gasket you touch on the burner. Clean the heat exchanger outlet. If there is any noise from the blower motor you may need bearings if it is a newer M422. If its older you may be able to oil the bearing. You can tell if there is a black rubber plug on the back and front of the motor. While you are at it oil the circulating fan motor and clean the fan.

Tom

[HayZee518]

monitor

the service manual doesn't tell you how to take it apart. removing items comes from experience.
the service manual tells you what to look for using a flow chart troubleshooting aid.

[catamount]

Thanks guys, I will order a new mat & ring today. I'll order the gasket material from McMaster-Carr.

One final question, does anyone have a mat template for the 422? I looked on this forum, but could only find one for the 41/441.

[FordMan59]

The burn mat should be cut in a circle the size of the bottom of the pot with a "V" about 1/2" wide and about 1/2" deep under the fuel inlet. The only other thing that needs to be cut is at the raised portion in the bottom of the pot. Make a cut on three sides of the mat at the raised portion of the pot so the mat will lay flat when glued down.

[catamount]

the service manual doesn't tell you how to take it apart. removing items comes from experience.
the service manual tells you what to look for using a flow chart troubleshooting aid.

Hmmm. Someone sent me the service manual yesterday, and it has step-by-step instructions on taking it apart.

[HayZee518]

service manual

well, I don't know about any step by step service manual. the only one I've seen that was scanned by another forum member was a trouble shooting flow chart. I do know the adenaue's took the basic manual and expanded and compressed items to make its use easier to comprehend.
other than the above I don't know much more.
I have in past posts explained how to take apart some Monitor heaters and what to expect.

[catamount]

Well, the manual certainly hasn't answered all of my questions.

For instance, here is where I'm currently stuck. Have burn chamber opened and trying to get to the burn ring. This tall metal "shield" is in the way. I removed a screw holding it to the wall of the burn chamber by sending a phillips driver through the viewing window port. I thought it would then lift right out. It does not. Maybe it is rusted in place? I pulled with quite a bit of force.

Do you happen to know about this tall sheild, and what it takes to remove it? I'm trying to get to the burn ring and burn mat below.

Thanks!

[HayZee518]

burner ring

the entire combustion chamber needs to be removed. the lower section of the combustion pot comes out from the bottom. its a sleeve within a sleeve. bottom of heater is a rubber elbow. disconnect spring clip and pull off the elbow. use a long phillips and remove the screws that hold the combustion pot to the heater base. watch it, there is a gasket underneath it. flip the pot over and remove screws around the circumference of the inner sleeve. it should now pull out. the burner ring is keyed to the inner sleeve by three long rivets. the burner ring needs to be rotated to dis-engage those rivets. there is three lever like pawls that interlock the ring.
while you are in there clean off the holes near the base and one third up the combustion pot. these provide air flow to give you that "turquoise blue" flame when the heater's operating.
mind you, the heat exchanger needs to be removed from the pot. gasket here too!

[catamount]

Okay, that explains it! I thought I was being efficient by trying to do everything from the top. I already have the long phillips driver, so I will remove the entire chamber this evening. Thanks for helping... glad I didn't try to force that shield out from the top!

I've noticed that a lot of people are using 9323K21 from McMaster for the gasket (1/8") Flexible Fiberglass Insulation Paper, 1/8" Thick, 16" Width, 10' Length. I've heard that this is sometimes "too thin" based on some posts I've read here.

I just found a different post from someone using 93315K71 (1/4") Ultra-High Temperature Ceramic Insulation Roll, 8 lbs/Cubic Feet Density, 1/4" Thickness, 24" x 20', White. I wonder if the 1/4" stuff might be a better fit for gasket material.

Any thoughts? Thanks HayZee!

[FordMan59]

Okay, that explains it! I thought I was being efficient by trying to do everything from the top. I already have the long phillips driver, so I will remove the entire chamber this evening. Thanks for helping... glad I didn't try to force that shield out from the top!

I've noticed that a lot of people are using 9323K21 from McMaster for the gasket (1/8") Flexible Fiberglass Insulation Paper, 1/8" Thick, 16" Width, 10' Length. I've heard that this is sometimes "too thin" based on some posts I've read here.

I just found a different post from someone using 93315K71 (1/4") Ultra-High Temperature Ceramic Insulation Roll, 8 lbs/Cubic Feet Density, 1/4" Thickness, 24" x 20', White. I wonder if the 1/4" stuff might be a better fit for gasket material.

Any thoughts? Thanks HayZee!

The 93315K71 material would probably be ok to use and is closer to the thickness of the original Monitor gaskets. I use 9323K21 and double the gaskets when needed. The thing I like about the 9323K21 is the strength of the material and it doesn't tear easily like the original Monitor gasket material. I'm pretty sure the 9323K21 gaskets could be used for multiple rebuilds without having to cut new gaskets each time.

[catamount]

Disassembly continued this morning, and when I got to the point of disconnecting the fuel line, I found it hanging completely loose. The weld joint must've come undone at some point, or during a prior repair (I used to bring this thing in for service, before I decided to DIY) which probably explains at least some of my yellow flame.

It looks like I'll be buying a burner pot now

[hawkins111]

burner insulating pad

Be sure to fit the old burner insulating pad on the new burner, as they do not come with one on. Take a good look at the factory installed burner mat to give you an idea of the correct way to glue the mat down.

Tom