Monitor 441

[troubled]

Evening Well I have a problem with my Monitor htr 441. I installed this htr in a new house that I'm building for my daughter. After installing it, it has been working great. Then sometime during the night it went into the over heat mode. I have tried several times by the installation book to restart it. No luck. I have come to the fact that I am not getting any fuel from the pump to the burner. When I restart it the main blower will not come on and goes back into the overheat mode. Also the auto button when pushed, the light above it will not light. thanks for any help

[HayZee518]

to reset the computer and the overload condition, unplug the heater and wait a half hour, then plug it back in. if by chance you removed the front panel and looked in there, there are two "klixon" overloads on the right hand upper part of the sheet metal "plenum." these are your overload cutouts. there are two of them connected in series as there are only two wires going back to the computer board. the computer will lock out because of an overload, no flame detected, low fuel etc. inside the sump there is a stainless steel screen you can clean off with gumout. you access this by removing two phillips screws and pull out the filter.

[troubled]

I have had it unpluged most of the day. Yes I removed the front sheetmetal, and yes there are two of those klixon switches on the front panel. There is also one on the top of that panel just above the two you are talking about. I have removed the fuel screen and it is clean and no debri there. Also the klixon switch on top if I jumper accross the main fan will come on. When I disconnect the line from the pump and push on the primer button nothing comes out of the fitting.

[HayZee518]

that primer button is a misnomer. it doesn't really "prime" anything. all it does is lift the needle valve so that kerosene fills the sump chamber. it is a part of the mechanical linkage that makes up the mechanical lockout. the lockout itself is a piece of stamped sheet metal that has a spring loaded toggle over center. when it trips it toggles itself over a center or middle fulcrum and flops over and shuts the needle valve. your system must go through an electrical purge using air from the combustion blower, then the solenoid operated fuel pump is supposed to pump fuel onto the burner mat in the "pot." by this time the ignitor should be glowing red or orange to ignite the fuel that is pumped into the chamber. when it ignites it creates a flame that the flame rod detects. the flame rod has AC on it until the air between the rod and the side wall of the chamber ionizes. this ac voltage then becomes dc to the flame sense circuitry and as long as it stays ionized the burner keeps going. no flame or a shorted condition between the flame rod and side wall will electronically lock out the system. the unit's ac plug must be removed then plugged back in to reset the computer. merely turning it off then on with the button won't do.

[troubled]

Ok for my sake lets back up. In trying to reset the computer I have been unpluging it from any where from 30 min to a couple hrs before pluging it back in. Just what is the computer, is it the panel that you make your adjs. to for heat time etc etc. The two klixon overloads you mentioned earlier, as I am facing the htr from in front of it are to my left. From the rear of the htr they would be on the right. Am I maybe looking at something different. Also these two klixon ouerload switches you mentioned, the two wire run down to a valve at the bottom of the htr with a plastic hose running from it.

[HayZee518]

Monitor heater

Attached to this message is a diagram/ picture of the guts of a heater. I think this is for an M21 heater but most monitors are constructed similar.

[troubled]

Great pic. Ok the computer, is there and way to know after I have pluged the power cord to the outlet. I know this may be a loaded question being that I'm working with electrial. Trust me this is not my strong suit.

[troubled]

I sort of left out the part of if the computer is reset or there is something else still wrong. Seems there is a sequence of test that could tell me this. maybe

[HayZee518]

here in the forum please direct yourself to ILLUSTRATIONS. Go down to the 7th post and click on it. In here you'll find an operating link to parts lists and an operational flow chart for troubleshooting the heater. thread says Monitor Heater Manual

[Artistic]

monitor 441

I have a question. I have 2 used Monitor 441s which worked at one location then after driving to another location on the thruway with the rear of the heaters uncovered toward the truck cab for 2 hours and then were put in a trailer. Once there and hooked up they would not work. Although the panel lights up, there is no sounds coming from the heaters and of course no heat. No sounds like no pump clicking on. what do you think. thanks