Monitor 441 Heater

[HayZee518]

Monitor 2400 Heater

I finally got a look inside a Monitor 2400. Mine kept on giving me an E-14 readout. The prepurge came on, I had ignition, but when the heater kicked into high, I got flame out and the heater would shut down and lockout.
I found that the fuel line had a water-ice blockage somewhere in the inlet line. Once this was cleared up the heater would run and run.
The front cover is removed by taking out two screw on the side(s) lower. Then by removing three screw on both sides and one screw right in the middle of the louver assembly comes out.
The combustion pot is the same, the flame rod is the same, the solenoid pump is the same exceot that it plugs directly into the computer board. The air proving switch is the same. The fuel sump is smaller and doesn't have an adjustment for the float. The float is plastic and pivots in a plastic holder. The float looks just like one used in a garden tractor. At one end of the float is a piece of metal. This metal piece contacts a magnet should the fuel level get too high in the sump. It is reset by using a lever attached to a button for the user. The combustion blower is the same I couldn't see the damper but there isn't the omlnous click when the heater clicks into high heat.

[onebatk]

hollow i hope i am in the wright place i have a 422 and here is my problem i turn on the unit it comes on and runs for a little them all the lights start to blink so i shut it off and restart it and it does the same thing this happens 2 to 3 times 4 time is a charm then it will run fine for a day or 2 then it starts all over again any ideals i am at a loss the unit is about 5 to 6 years old

[HayZee518]

what causes the error lights to blink [ burner lights]
1) no fuel
2) no flame
3) overheat condition
4) grounded flame rod
If the unit while running exhibits a shallow clunk, clunk, clunk noise your fuel pump is being starved for fuel and will eventually shut down your heater. Check for a blocked fuel line, frozen fuel line, clogged fuel filter below the sump.
Remove the flame rod and clean it. if a piece of soot bridges the center wire and the porcelain sleeve, it will cause the lights to flash in a locked out condition.
RUN ONLY RED DYED KEROSENE CLEAR KEROSENE DO NOT RUN DIESEL FUEL OR BIO DIESEL.

[HayZee518]

the air switch is a diaphragm so it needs to be open to atmosphere. the other tube connects to the combustion blower housing so there is a pressure differential across the diaphragm. with the combustion blower operating air is sucked in via the outside double tube and heads towards the combustion pot a sample of this air is sent to the air proving switch. you can check out this switch by temporarily jumping it out. once a prepurge time is satisfied the solenoid pump turns on and the ignition element heats up and ignites the kerosene vapors. once a flame is established the flame rod activates and proves there is a flame. the kerosene vapors and air ignite and burn which ionizes the air between the flae rod and ground, changing the ac to a dc current which is applied to the electronics.

[Spantar142]

I found this thread via google and it has helped me fix my 441. I did run into a little problem that I hope someone has an answer for. I was cleaning the fuel line from the fuel solenoid to the burn chamber and when I took it off it was cross threaded. Does anyone know if the Male end in the burn chamber is replacable or how I and re-tap the threads?

[HayZee518]

I imagine its replaceable. once you get it out check the threads using a thread gauge. It may be an SAE thread or being from overseas, probably is a metric thread. the fuel tube looks to be brass and the ferrule is steel.

[ScottyG2335]

Monitor 441 Exhaust Problems

I hope this is the right place to post this. There are a few different threads about the monitor heaters as evryone else seems to have the same problems finding quality service. Our 441 first quit 2 days before Christmas. We took it to on service place that diagnosed the problem as a clogged line. The small brass line into the burning pot was sooted up and causing the stove to not get oil. In the process the brass fiting broke off and the burning pot had to be replaced. Since we brought the stove home and reconnected it, We at times were getting a kerosene smell that reminded me of when I was younger. Annoying but livable. Since then we are getting a strong exhaust smell in the house and I'm worried about carbon monoxide. We called a second company to come look at the stove. This serviceman replaced a filter on our external tank and cleaned some soot from inside the exhaust flue. It worked ok for about a day. I thought the carbon probably came from whatever problem was created by the first repair. Any ideas what to check next? If I put much more money into this unit it may be cheaper to buy a new unit. Please help!

[HayZee518]

kerosene smell is due to gaskets not sealing or O rings that are cracked or split. only place O rings are - are at the offset nipple on the heater rear and the outlet tube going outside. the main access port has a fiber gasket and the view port has a gasket. the first fin of the heat exchanger has a fiber gasket. and four screws that hold it on.

[ScottyG2335]

kerosene smell is due to gaskets not sealing or O rings that are cracked or split. only place O rings are - are at the offset nipple on the heater rear and the outlet tube going outside. the main access port has a fiber gasket and the view port has a gasket. the first fin of the heat exchanger has a fiber gasket. and four screws that hold it on.

Thanks. We did replace the two O rings. I'm not sure what the access port is. Where can I find a good diagram of those areas? Thanks again. You seem to be the expert on here. You have halped a lot of people.

[HayZee518]

Monitor

I got sick n tired of asking for monitor helps and getting charged way above my means so I looked into repairing my own heater. Parts in themselves are expensive enough but when you start getting charged $45 an hour to repair a heater ya got to draw the line somewhere. Monitor is a unique product and the manufacturers know this that's why they can charge $146 for a blower motor that's no bigger than three inches around. boro silicate gaskets are cheap enough. Monitor sells a main access port gasket for $16.50 - I don't know if it's even asbestos free - never bought one.

[tonybegley]

another similar m441 problem

Regards from Windham, NY. Thanks everyone for all the help. I have a similar problem to many. My Monitor 441 worked fine for many years (with no service)but recently it would shut itself off after an hour or so of good operation.

I cleaned the internal filter and took the top off the internal kerosene (red) tank. All looks good. The level looks good. Pushing the float downraises the level fine. Flow looks good.

I took the front inspection plate off the burning chamber (carefully trying
not to destroy the gasket). The flame rod looks fine. No obvious bending or
carbon flakes.

I unscrewed the copper fuel line at the burning chamber. I note from the
other useful monitor thread (thanks so much for the scanned manual and the
details here):

6921-definative-monitor-thread-2 dot html


>
> Starts up, shuts down. Does the fuel come to the heater, but is blocked
> from the combustion chamber? It is easy to check. Where the small copper
> fuel line enters the combustion chamber, it may be inspected. Use a 13 mm
> open end wrench, or small adjustable wrench, disconnect the line from the
> combustion chamber. The line pulls out, and so do the washer and rubber
> spacer; don?~@~Yt lose them. The fuel line itself does not clog, but carbon
> may build up on the tube that goes into the chamber, partially blocking fuel
> from getting to where it needs to be. If this is the case, the symptom will
> be start up and shut down, with an error code of flame failure. Essentially,
> it ran out of fuel. A drill bit may be too short, but a piece of bailing wire
> 3 inches long (I use a bicycle spoke) will be enough to push carbon out of
> the way at the far end of the fuel inlet. If carbon is blocking the inlet,
> you will feel it as it pushes out of the way. If there is no resistance
> at all, there was no blockage. While this is not the condition with every
> heater that stops, it is easy to check, and it is easy to overlook. Put it
> back together, and move on to the next common problem.
>

This is my one big difference. It says 3 inches into the chamber but on my
441 model, there is something metal blocking the path about 1 inch in. I
scraped this and carbon came off (as you'd expect). Any advice? A different model? Is there a schematic/description of where the fuel goes in the chamber?

After this tinkering the 441 won't stay lit. I d see orange flame but it switches off after only a minute or so. I presume fuel problem.

I presume I have to open the chamber from the top now and have a good
look around. Thanks for the instructions on how to do this, HayZee518.

Tony

[adnadeau]

I bought an extra-long 1/8" drill bit from Home Depot and used that to ream out the fuel nozzle into the burn chamber. It did go in about 3". If you look on page 40 (as printed on the manual) fig 5.5 you'll see that the fuel nozzle and nozzle collar extend into the chamber a little less than half-way, about 3". According to the manual, you can use an easy-out to "break loose" and remove the nozzle. Sounds like you have a blockage in the nozzle.

[HayZee518]

monitor

I'm gonna need to make up an illustrated book on the monitor. the following drawing shows the fuel tube, the fuel extension tube, the igniter, the fuel channel and the burner mat. hope it helps you. the flame rod you can remove using the two screws. that way you won't disturb the access hatch gasket. a new one from mpi costs 16.50.

[tonybegley]

I bought an extra-long 1/8" drill bit from Home Depot and used that to ream out the fuel nozzle into the burn chamber. It did go in about 3". If you look on page 40 (as printed on the manual) fig 5.5 you'll see that the fuel nozzle and nozzle collar extend into the chamber a little less than half-way, about 3". According to the manual, you can use an easy-out to "break loose" and remove the nozzle. Sounds like you have a blockage in the nozzle.

Thanks to you all. I admit (shameful for this forum) that I just took the M441 for a service to the Monitor dealer on Long Island (Islandia, close to where I live). Nice guy. Seemed very expert. Runs the business from his house. www dot bran-art dot com. So close to my LI house that I felt I had to. Another dealer was in Arkville, NY.

You were right. There was so thick a carbon deposit inside my burner pot in the fuel nozzle that the guy had to drill through it (as I would have done if I'd had the confidence). He said it was the worst he'd seen. The burner dish was also completely warped and slightly cracked. No wonder no fuel was getting in and the flame was prob too close to the sensor.

Cost me a fortune, of course, as we replaced all the gaskets and the dish and the sensor rod, etc. There was also an issue with the internal kerosene tank as the rod holding the float had come out and was blocking the fuel flow up. I haven't tried my refurbished M441 out yet but am sure it will be fine so I am happy. It was fully tested at the shop.

In case it is of use to anyone, the guy told me:

(1) don't open up the internal kerosene reservoir, which I had done. It is rather sensitive and can easily be messed up. The M441 old reservoir I have is not made anymore (the one with the long 3" filter) and is actually better than the new one (short filter). Def don't mess with the screw to control the flow (as mentioned before).

(2) He was paranoid about breaking the welded seal of the fuel line just inside the burner chamber. Never unscrew the copper fuel line from the burner chamber unless the chamber is cold. It is easy to crack this weld and then you need a new burner chamber (which he has).

(3) He was paranoid about the cleanliness of the kerosene. Change the external fuel filter every year. Watch for water, especially.

(4) On my 441, all chamber repairs were done via the front access panel; he didn't ever need to open the chamber from the top. The burner pot did twist off but obviously may need some tugging as it gets rusted.

(5) He likes the monitor much more than the toyostove (which he also sells and one of which I also have, L56). Both good but monitor has finer control over fuel flow.

There was a fair bit of carbon at the bottom of the chamber. Seems like we should vacuum this out once a year. The sensor rod seemed Ok but we changed it anyway as it was blackened on the insulator.

Hope this is of help to some. Probably all predictable to you experts :-) but I don't mind paying good money to businesses that are run out of peoples homes. Where would we be without them. That's my excsuse and I'm sticking to it.

I do again praise you all for sharing all this good info. Next year, I'll service it myself.

Regards,

Tony

[Firebird]

Hello and thanks.

Just wanted to say thanks for the useful info here. Also that it is really good to find a forum where people have respect for each other without flame wars. I have a 4200 and get to tinker with a 441 sometimes and fairly well understand the idea of how they work but have gotten a lot of good detail info from this site. Repair service here is poor. It's like do part of the job and then come back to do some more. They don't seem to know what customer service is but they do like to collect your money. That's why I have fixed my own things for the last sixty years. People like you help a lot. Also I could use service manuals, I have owners manuals. Thanks