Monitor 441 Heater

[dr.tech]

10 year old 441

I have a 10-year old 441 (and a 6-year old one). I do not have a Monitor dealer anywhere near me and have not serviced them since I purchased them. I love them by the way. The 10-year old one has started acting up last season ... shutting off sporadically, low flame, bearings starting to make a noise.

I'm thinking of dropping it off for a full reconditioning when I drive through the area where it was purchased, but I'm guessing that they are wanting close to the cost of a used, refurbished unit (circa $900) to make these repairs to mine.

• Should I consider doing it myself? ....
• How goof-proof is it to do a major refurb?
• I saw info on this forum re: options to replace gaskets. What about purchasing other replacement parts, like the pot, bearings, etc.?

I don't mind replacing things that are questionable (if i'm doing the work) so a parts list of what ought to be replaced would be helpful.

Any sage help is appreciated.

thanks in advance

[HayZee518]

Monitor parts are Monitor parts. They are not interchangeable with other vented heaters even many look the same. The bearings on the combustion blower are the same ones used on inline skates. the gaskets can be gotten from mcmaster-carr at a price way lower than what mpi charges. the temperature ratings on the mcmaster gasket material is higher than what mpi uses. the thermister can be obtained from Mouser electronics in Texas. Other than what I've annotated mpi charges top dollar for replacement parts but those parts are unique to Monitor. A solenoid pump will set you back about $45. The blower motor, $145. mpi gaskets like for the pot access flap is $16.50. The mica or quartz glass ised on the window is $55 for a small 1 inch X 2 inch piece. Boro silicate glass from mcmaster costs 5 bucks for a 2X5 inch piece. Tell me specifically what you want to do and I'll tell you what you need - hayzee.

[tommygraves]

41 Help Please...

HayZee - amazing help on this forum. Thank you so much! I would greatly appreaciate if you could please email me the 41 service manual. I'm at tommygravescustoms@msn.com. My 41 is acting up again and could really use the manual....Thanks in advance!!!!!

[mrsargemeister]

Combustion blower question

Hayzee, thanks for supplying all the technical information in this thread, it is very helpful. I have a question about the combustion blower in my monitor 41. This heater is new to me so I am not sure how its supposed to sound. My combustion motor is not completely silent it does emit a noise louder then I would assume appropriate. Maybe you can tell me if this is normal or not. I have removed the inlet pipe from the back of the unit and the impeller shaft moves smoothly and freely with no freeplay. This would indicate that the bearings are good. What are your thoughts? Do the bearings in this motor need to be lubed? If so is this a difficult job? Thanks for your help!

[HayZee518]

the sound of the combustion blower on its way out was compared to the whinning sound of a jet engine starting. the motor emits a start sound as it gets up to speed. that little motor has to get a six inch disk up to about 1000 rpm. I wrote an email to mpi asking why they never give out a rebuild manual. they said it was an issue of liability. so, here we are examining a product that needs repair but they won't help us. Oh! but they will! At about $150 an hour just to protect their liability.

[mrsargemeister]

I removed the combustion motor assembly, took it apart everything looks ok. I think I should replace the bearings anyway. They say "NMB Z809". Its stainless double sealed ball bearing. Is there another size this can cross over to? I cant find any Z809.

[HayZee518]

The bearing is a 608Z you have the number upside down. They are the same as used on inline skates. The bore is 8mm.

[Pockets]

Hi Hay,

I've been reading all the posts here and can easily see you are well aquainted with the Monitor heater. I purchased my Monitor 41 about 15 years ago and installed it myself. I haven't had a single problem in all these years and try to avoid trouble through regular maintenance. Since firing up my heater this fall I noticed that, on start-up, the flame takes about 5 minutes before all the yellow flame disappears. Once it does it's fine, beautiful blue. Is that normal behavior or is it a sign of trouble? Should I replace the mat or other parts or is it a "if it ain't broke don't fix it" thing? I do have the parts available from a local dealer. I would like to get a copy of that service manual you have also. deswallow@gmail.com
I'm in awe of the time you spend to help all the people that you do on this site. These heaters are a real jewel but the information on them is really scarce. Kinda like prospecting for gold, I've struck a vein here!!!! Thanks, pockets

[HayZee518]

a nice turquoise blue flame is always nice to see. that means the air/fuel ratio is just where it wants to be. the heater's efficiency will be 87% as stated in the manual. somewhere down the line in your maintenance, take the top off the combustion pot, careful not to break any gasket material and look at the burner ring. this thing is like an upside down stainless steel bowl. if it is warped get a new one. warpage is why you see a yellow flame. beyond the ring down in the bottom of the pot is the burner mat. when the heater was new it was glued to the bottom of the pot. the flame rod goes into the side of the pot with two screws. clean it with a solvent. this also has a gasket under the bracket. it's your call to do any maintenance on it. like you said "if it ain't broke, don't fix it!"

[mrsargemeister]

So I was working on my Monitor 41, cleaning the combustion chamber and when I reassembled everything and plugged in the AC cord, nothing works. The display window is completely off and I'm stumped. I double and triple checked all the connectors, and ribbon cables with no luck. I verified that the board is getting 120VAC through the main power connector. I checked various test points on the board and those voltages appear to be normal. All the fuses are good. Any ideas? Does anyone have a monitor 41 service manual?

[mrsargemeister]

my PMs dont seem to be working. My email address is

mrsargemeister AT yahoo dot com

thanks for all your help. any other suggestions?

[HayZee518]

I tried to upload the pdf file I have. My isp wouldn't let it transmit. Please look into the HVAC sub section, monitor heaters for another pdf file someone has saved on a remote site. You can d/l it from there.

[randy j]

I would like to thank HayZee 518 for all the information he has posted. I just put my Monitor 41 back together after rebuilding the combustion chamber and the combustion fan. It is so quiet I can't tell that its running, Ah but I can feel it!

[crann]

new member/ 441 problems

first off , this forum is great and hayzee is due much thanks for his contribution.
now for my problem: in doing my yearly ,main tank, filter change the canister (general 77 ) sprung a leak and i replaced it with a new canister and filter . leak stops and i turn the main valve ,feeding my monitor 441 heater, on . the heater starts up OK and i let it burn for a few minutes and reset to a lower temperture and it shuts off. i return 15 hours later to find kero overflowing the pan and quite a mess of clean up. i remove the grill and find the right side compartment floor filled with kero. once mopped up i can feel
wetness at the bottom of the pump housing. the lines going to the pump and burner are dry. my question is , wouldn't the pump housing be a sealed unit ,even if a float was faulty? also, any ideas on why this happened. i think this could have been a much worse situation. i read the posts from this thread and saw no mention of this problem . HELP !!
my e-mail address is aquinas@syracuse.net if i could get a copy of the repair
manual it would be invaluable. thanks in advance ! thomas

[HayZee518]

the fuel sump isn't sealed because the fuel is gravity flow. in your case, shut off and unplug the heater. shut off the fuel flow to the heater. remove the front grill, drain what ever fuel is left in the sump. remove the fuel line from the left side of the sump and four phillips screws and remove the sump. take the top plate off and use gumout and clean all the crap out of the sump. it sounds like your toggle over center lockout got stuck. kerosene left sitting gels into a snotty mess. lack of fuel sets the lockout, too much fuel sets the lockout. in either case the lowering or rising of the float seals off the needle valve if it travels to extremes. the newer 2400 only has the high fuel lockout option.