Monitor 30 heater won't light

[rrob311]

I picked up a monitor 30 heater and it turns on and I can hear the combustion fan run but it won't light. It hasn't been used in years. I read the manual but don't see a strainer to clean. I would like to get it up and running. Any tips on servicing this? It seems like it isn't getting fuel.

[akaothermick]

There is a strainer in the base of the fuel pump, but there could be more than that, needs to be done, I also have a 30 and it was a non functioning unit when I got it, they are well built but over 30 years old, so you could be in for more than just a dirty strainer, but they are still repairable if you are capable, and understand how they operate, and with a comprehensive set of tools

[rrob311]

Mine was used for years and then stored. It has just been in storage for awhile. The 30 is definitely heavier than my 40 or 41.

[FordMan59]

I picked up a monitor 30 heater and it turns on and I can hear the combustion fan run but it won't light. It hasn't been used in years. I read the manual but don't see a strainer to clean. I would like to get it up and running. Any tips on servicing this? It seems like it isn't getting fuel.

Provided the fuel pump is working, if it's not getting fuel to the sump there's a good chance the fuel pump will make a thumping noise. Is it possible that while in storage dirt dobbers or wasp built a nest in the fuel inlet tube restricting fuel flow? Could also be the tube going from the sump to the pot is clogged with carbon at the pot. When I first installed my 422 in '96 I had the same problem, the combustion fan would come on, but when it should have fired up it would shut down and I'd get blinking burn status lights. My problem ended up being air trapped in the copper tubing coming from the outside fuel source to the heater. I bled off the air and got good fuel flow to the heater and the problem was resolved. Have you confirmed that the igniter is working? Have you checked that the flame rod isn't shorted out on the burn ring? I have service manuals for most Monitor units and would be glad to share with you to help you find your problem, but I don't have the manual for the 20 or 30.

[rrob311]

I will check that within the next few days. I am currently working on a M40 that I just bought and it would fire up and then smoke and trip the burner flashing lights. So I cleaned out the fuel tube to the burner and the inlet tube which were both coked. Now the heater smoked more and tripped the light. So I proceeded to remove the lid to the pot and found that the burner ring was sitting inside the pot sideways and upside down! Someone obviously took it apart and fooled with it. The ring is slightly warped but I think it should work for now once I get it set in correctly. Once the 40 is working correctly I will continue working on the 30.

Incidentally I can't hear the fuel pump do anything when trying to fire the heater on the 40. Does the pump come on after the heater is lit and drawing fuel?

[HayZee518]

OK, the pump comes on after all the permissives say so. That means the air flow proving switch. That sideways aluminum can with hoses coming out of it. there's a lever type mini microswitch on it that closes when there is air flow. Next, the two plenum mounted overload switches. These are normally closed. They open when the temp goes over a certain value. Another plenum mounted switch starts the circulator fan. When you start the heater, the igniter turns on and so does the combustion blower. The bottom of the combustion pot should feel slightly warm at this point. After a 300 second pre-purge, the fuel pump turns on and your heater should light. If there's no flame after 30 seconds, the unit will go into lockout and you'll get all 8 indicators flashing. What you need to do is turn off the heater, unplug the heater, then plug it back in. with the ac wall plug plugged in, power is fed to the computer all the time even if the on-off switch is off.
did you listen to the blower? if it sounds like a jet engine winding up, the blower's bearings are going bad. these are 608Z bearings, internal bore is 7mm. same bearings used on inline skates.

[Bryand]

Pretty sure this post is about a Monitor 30. Monitor 30's are a totally different bird than the 40's and newer. There are no lights to flash no pumps that make noises and flame rod sensors.
Check the oil line going into the burner to see if it is stopped up with carbon the 30's were bad for this. If not on top of the sump you will find a small black vacum hose that goes back to the blower. You can take the hose off of the blower and when the first two lights low and medium come on you can blow into the vacum hose not real hard and see if it lights. Sometimes these 30's need a little help getting started after sitting for a while. If you notice where you remove the hose from on the blower it was a small copper line. you can take a coat hanger and run back in that line, with the heater not running and clean it out. the hanger can go a foot before hitting anything. Sometimes small carbon builds up and does not allow for air flow to go into the top of the sump there for not assisting with the fuel flow. This heater does not pump kersone like the 40's and newer ones. It does have two selonoids that the fuel goes thru. There is a filter in the bottom front of the the sump and also a primer that runs virticle infront of the sump. With this one you can pump it 3 or 4 times to get fuel once again not like the 40's. Also in the very back of the heater on the inside is a cut off like the ones on the 21's and 422's that you can cut the fuel off to the heater to work on it. But it is reverse thread. If the handle comes off in your hand it is cut off if it is screwed all the way down it is on.

[rrob311]

Ive got the Monitor 30 apart right now. I removed the fuel line to the burner and I have no fuel coming out of the solenoid that the fuel line threads into. I tried to prime the bowl with the vacuum line but I am still not getting fuel out of it. The kerosene in the bowl is pretty old and smells varnished. Is the solenoid that the fuel line threads into some sort of a shut off valve? What can I check next.

[Bryand]

Ive got the Monitor 30 apart right now. I removed the fuel line to the burner and I have no fuel coming out of the solenoid that the fuel line threads into. I tried to prime the bowl with the vacuum line but I am still not getting fuel out of it. The kerosene in the bowl is pretty old and smells varnished. Is the solenoid that the fuel line threads into some sort of a shut off valve? What can I check next.

When you say prime the bowl with the vacum line what do you mean. Also you can cut the oil off and take the solenoids off and hold them ensure you are not touching any connections turn the heater on and when the low and medium lights come on the solenoid should open up to allow the oil to come thru. It could be that one of them or both could be stuck. may have to clean them. each of them has two small long screws that screw them in.

[rrob311]

When you say prime the bowl with the vacum line what do you mean. Also you can cut the oil off and take the solenoids off and hold them ensure you are not touching any connections turn the heater on and when the low and medium lights come on the solenoid should open up to allow the oil to come thru. It could be that one of them or both could be stuck. may have to clean them. each of them has two small long screws that screw them in.

I tried blowing into the bowl and actuating the lever. Still no fuel coming out of line. I will check the solenoids next.

[Bryand]

I tried blowing into the bowl and actuating the lever. Still no fuel coming out of line. I will check the solenoids next.

Did you have fuel coming out of the sump when you took filter out. There is also a larger screw next to the filter you can loosen and see if you have fuel in the sump

[akaothermick]

I had the same issue with my Monitor 30 when I got it, I didn't try to analyse it, I planned on a complete rebuild so all the fuel system was cleaned inside and out with laquer thinner and carb cleaner, solenoids fuel pump, valves, and lines got completely cleaned and blown out, cleaned everthing, combustion pot was beadblasted and check for cracks, all air and fuel ports cleaned as new, new fan bearings, upon reassembly the unit fired up and ran without any problems and functioned flawlessly, so the problem in my case was just years of crud building up to a point where it inhibited the operation of the unit

[rrob311]

Ya there was fuel coming out of the bowl and the drain screw when I opened them. Just nothing past that.

[HayZee518]

Then I would look towards the fuel solenoids, the chain of events that must occur before the fuel pump turns on etc. read previous threads. There's a whole section since this sub directory was started. Monitors aren't hard to troubleshoot.

[hawkins111]

On EBAY I saw a safety solenoid part # 4031 for sale. It's just the coil, not the whole part. I don't show that part number on my list, so I'm not sure exactly what they have. If you are still having problems you may very well know what they have. Tom