Monitor 2400 carbon buildup

[Elm494]

Hello to everyone here !! I have used info on here to repair my heaters many times. I have 3 buildings with Monitors in each one. One shop seems to have consistent problems with heaters. Over the last 15 years I have had 3 different units in this shop and all have had issues. I have a 2400 now that I rebuilt myself last winter. I replaced the Burn Pot and Ring with new and it worked great for the remainder of last year. This winter it started shutting down shortly after startup so I changed the filter at the tank, cleaned the sump, cleaned the flame sensor and it started and ran good for a week. Then at 2:00 in the morning I get a call from my alarm company telling me there is a low temp alarm in my shop. Not really wanting to fix a heater in the middle of the night but here I go, I took the front access door off, pulled the burner ring and the carbon was built up all around the pot. I scraped it, sanded it and vacuumed everything up. Started her up and there was a nice blue flame. Now one month later the same exact carbon buildup has happened again. There was snow close the flue pipe which I cleared. I see no blockage to indicate its not getting air and I'm out of answers. This time I pulled the pot out, sandblasted it, installed a burn mat, vacuumed the air intake tube and put it back together. Its running great now but I have no confidence in it anymore. I would love to hear from someone who has ideas on what could be the problem. Thanks !!!!

[hawkins111]

Two questions here, what about the snow "close" to the exhaust and what kind of fuel are you using??

Tom

[Elm494]

Hi Tom, We had a good wind/snow storm and the snow drifted half way up or around the Flue. Part of me wonders if the exhaust is too close to the ground. Its about 12" from ground level. As far as the fuel goes I use dyed Kero. The same tank feeds 2 shops and I never have problems in the 2nd shop.

Thank You for any help you can offer !!

[hawkins111]

Since the sooting happened before the snow storm I would say it's not the flue being covered. Monitor has a pretty good air safety switch system. The least little block of either air or exhaust is enough to trip the switch and shut off the fuel. What about the flue itself? Remove the air cap and look at the exhaust part of the pipe. Is it black or corroded through. Look outside as well near the tip of the exhaust. Are there any holes in the pipe? When you removed the burner did you clean out the heat exchanger? Tom

[Elm494]

I'll check the flue later today when it warms up some. I've never cleaned a heat exchanger, how do you clean it ?

Mike

[HayZee518]

you have to physically remove it from the system. Messy at least. Use a nylon round brush and scrub out what you can reach from both ends Then use a coarse sand and pour some inside the exchanger. Then move it around to dislodge any soot inside. After you've cleaned it out use a vacuum to remove the sand and an air jet. Then using a new gasket re-assemble to the heater's "pot."

[Elm494]

I checked the flue where it comes out of the building. The outside areas look good but there is some black soot on the inside of the Exhaust. I also removed the heat exchanger and cleaned it as per Hayzee's recommendations. It didn't appear to be very dirty though. The worst part of all this is that I won't know if its fixed until it runs for a month or longer.
At least its nice and clean with a different Burn Pot on it

[rrob311]

Maybe exchange the bad heater with one of the consistent ones and run it there and see what happens. Maybe your tank is contaminated causing the fuel to not burn well.

[Rc494229]

Did you ever resolve the issue? I have the same issue happening with a monitor 2400 I did a full service to in last season including a complete burn pot but I am having an issue with it building carbon up and shutting down.

[HayZee518]

Incomplete combustion is directly related to air flow. If there isn't enough of air then the kero burns rich with yellow flames and creates soot. this will blacken the insides and the view window.

[Rc494229]

Incomplete combustion is directly related to air flow. If there isn't enough of air then the kero burns rich with yellow flames and creates soot. this will blacken the insides and the view window.

What would cause this to happen?

[HayZee518]

semi blockage of the inlet air pipe, bad bearings on the motor, internal short in one winding. replace the combustion blower motor.

[Rc494229]

semi blockage of the inlet air pipe, bad bearings on the motor, internal short in one winding. replace the combustion blower motor.

I know there is no blockages in the intake I had made sure of that where can I still get the combustion fan motor?

[HayZee518]

I think Fordman was able to get parts from a place called Hickory Hill [something] another place is Adirondack Hardware [Keeseville NY]

[Rc494229]

Thank you for the responses is it just a motor or the whole assy? What gaskets would I need to replace to change it?