Monitor Heater 441 not lighting

[Moon]

I have a Monitor Heater 441 that will not light. I have checked everything. It has plenty oil. It comes on and the burn chamber gets hot but there is no flame.

[HayZee518]

441

all of the inline safety devices have to be closed before the pump will pump fuel.
is the combustion blower running? is the air proving switch closed?
is the igniter warm to the touch? the igniter is behind the silver dimpled cover at the lower left of the combustion pot.
is the flamerod touching the burner ring or the pot side? is there a carbon bridge between the side of the pot and the flamerod?
is there a carbon build up between the center electrode and the porcelain insulator of the flamerod.
have you checked for a blocked air inlet from the outside? wasps love to make their nests in the tube.

[Moon]

Monitor Heater 441 not lighting

all of the inline safety devices have to be closed before the pump will pump fuel.
is the combustion blower running? is the air proving switch closed?
is the igniter warm to the touch? the igniter is behind the silver dimpled cover at the lower left of the combustion pot.
is the flamerod touching the burner ring or the pot side? is there a carbon bridge between the side of the pot and the flamerod?
is there a carbon build up between the center electrode and the porcelain insulator of the flamerod.
have you checked for a blocked air inlet from the outside? wasps love to make their nests in the tube.

How do you check if the inline safety devices are closed? No, the blower isn't running. Where is the air proving switch? The burn chamber gets warm or hot to the touch. Do I have to remove the silver dimpled cover to find the flamerod? How do I see if the flamerod is touching the burner ring? What is a carbon bridge? How do I find the center electrode and porcelain insulator to check for carbon build up? The flu to the outside seems clear. I ran a stick all the way up into it. Thanks

[HayZee518]

can of worms 441

Please look into this forums threads. There are loads of pictures that others have taken along with tons of information. If you have never serviced ANY monitor heater then me trying to show you where items are isn't going to help much.
If the combustion blower isn't turning then nothing else will work. You say the combustion pot is hot. So, I guess the igniter is working. Get that combustion blower spinning or you won't get anywhere FAST!.

[catamount]

Moon, there are two fans -- the combustion fan (located on the lower right of the unit, in a part you can't easily see) and the blower that sends the hot air into the room (that is easily visible behind the unit). Are you sure the combustion fan isn't on?

[MH_in_Maine]

Combustion Fan

I just finished this very same troubleshoot today. I had to remove the plastic flexible air intake pipe on the rear of the unit and put my finger in the intake to manually spin the fan. Something was jamming the blades, maybe a dead wasp. The unit runs fine now, but I can still hear something touching the metal fan blades. Will remove fan and investigate further tomorrow.

[Moon]

Combustion Fan

Thanks for that bit of info. I will check that out as well.

[vipmaint70]

This summer on a regular service call i went out to do a general cleaning on a 2400 and the same symptoms occured during startup and i found the blower motor was not running just making a humming sound...pulled intake hose from back of heater and found the blower was jammed and not spinning...took it apart and found a dead mouse in there...the mouse had chewed a hole in the extension kit that ran along the wall to the corner of a room and crawled back into the unit...cleaned everything up and put it back together and worked fine.

[Moon]

Monitor Heater 441 not lighting

I was working on the heater again today and took the screws loose that hold it in place so I can move it away from the wall enough to take the flexible air intake hose off to check for obstructions in it. It is too close to the wall to remove without moving it out some but it still won't budge. Do I have to disconnect it from the exhaust pipe that goes outside as well and how do I do that? Do I got outside and remove the flange first ?

[HayZee518]

monitor

if it's stuck with the exhaust pipe in the heater then the whole exhaust/inlet will have to come out with the heater.
outside there is a large stainless steel nut. unscrew this, then remove the black rubber grommet. observe the way it is installed. should be an arrow pointing up or the word "up"
then go into the house and pull the unit straight out from the wall.
oh yeah, disconnect your fuel line first. shut off the flow and drain the line.

[Moon]

Monitor Heater 441 not lighting

Thanks, HayZee. I did remove the nut, grommet and rubber seal and pulled the heater out just enough to get the flexible air intake hose off to check it without having to unhook the fuel line. The hose is clear and the fan spins... it seemed a little stuck at first, but then it would spin freely. Should I turn the fuel line from thectank on and try it again now or is there something else that I should check first?

[hawkins111]

Anti-seize on "O" rings

While you have the stove out, remove the exhaust pipe from the z pipe and outlet adapter. Remove the "O" rings from the exhaust flue and the outlet adapter. Coat them with Anti-seize compound and put everything back together. Now, next time you need to remove the stove it will come apart easy. This will also help you getting everything all the way together.

Tom

[HayZee518]

monitor

stick the tube within a tube outside so it clears the siding.
open your fuel flow valve and wait a few minutes.
press the red button once.
turn on the heater and listen for the blower.
if there's no obstruction and it spins up, wait for the pre-purge and start cycle.
watch what happens

[Moon]

Thanks Hawkins and HayZee I will try that tomorrow.

[Moon]

I took the nut, flange and rubber gasket off the exhaust pipe outside and was able to move the heater far enough away from the wall to remove the flexible air intake hose to check it for obstructions. There were none. Using a hand mirror, I put a screwdriver into the opening to turn the fan blades. They seemed stuck at first, but then spun freely. I couldn't see the fan as it is inside of a metal casing. I put it all back together, moved it back into place, replaced the rubber gasket, flange and nut outside and tried starting the heater again. It came back on right away and is working fine ! Thanks to everyone for all your help.