Announcement

Collapse
No announcement yet.

The DEFINATIVE Monitor Thread

Collapse

Forum Top GA Ad Widget

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    There's more:
    Click, click, click. Your Monitor heater has a solenoid pump, about the size of a marking pen, that operates quietly when fuel is present at the fuel sump. If your tank ran out, or there are air pockets in the supply line, then you will hear the fuel pump click, click, click. That is the sound of a fuel pump without fuel. The red button reset (not a primer) at the lower right side of your Monitor heater releases a magnetic valve that may be stopping your fuel. If so, you will hear the click click go to clunk clunk and thump thump as fuel reaches the pump. If air in the line prevents fuel reaching the heater, it will need to be bled from the line to bring a steady fuel supply to the heater. This is not a heater problem. It is a fuel supply problem.

    Heater won’t start. Is it plugged in? Does the indicator light illuminate? Do your hear the hum of the combustion fan, but nothing else happens? Find the air switch. It is cookie size, stands on edge near the front of the same compartment as the Constant Level sump. The air switch has a micro switch with two wires attached. When this switch closes, it tells the control board all is well (the combustion fan is bringing air into the combustion chamber). What activates this switch is the rubber air hose attached to the cookie size air diaphragm. Occasionally, this diaphragm fails, but more often it stops working because the rubber air hose is split, right at the end attached to the air switch assembly. This split rubber hose will prevent the heater from starting the burn. You could go to the trouble of ordering Monitor part number XXXX, but why bother? I use 3/32”automotive vacuum hose, from the auto parts store. Quicker, cheaper, lasts longer. Clear silicone tubing is NOT recommended.

    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’t 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.

    Flame failure. The flame rod is telling the control board to shut down the heater. Why?

    The flame rod has a job to do, and while it is not a union job, it requires very specific working conditions. When the heater is operating, you may be able to look into the inspection window, down and to the right. To see it in its working position when the heater is not operating (and cool), remove the window base panel (10 screws, the panel 4 by 7 inches on the front of the combustion chamber. If the gasket goes to pieces, replace it with Monitor part number 6850, about $16). The flame rod is to the right and below the opening. Use a flashlight to see where it is, between the burn chamber wall and the burn ring. In this half inch opening, it should be centered. If there is carbon build up (a carbon bridge) from the rod to either side, the heater will shut down. If the burn ring is very near the rod, it may touch it as the heater warms up, and the heater will shut down.

    How does the flame rod work? It conducts electrical current through the flame itself to the board, telling the control circuit the flame is present and all is well. If the rod shorts out by carbon, or by touching the metal on either side, the signal to the control circuit is that all is not well, and the board responds by shutting the heater down. The burn ring, or combustion ring, looks like a cereal bowl upside down in the middle of the heater. It is stainless steel, and glows red hot in heater operation. New, it starts out perfectly round, but may warp over time. If the warp is wide at the flame rod position, and touches the rod, that condition can shut down the heater.

    @@@

    Proceed to Level Two?

    jimmyj55.com is restocking Monitor parts for the season, for all those who insist (by intent or by desperation) on repairing their own heaters.

    Comment


    • #17
      Testing Monitor 41..

      Can the M41 be tested without a direct connection to an external fuel supply? IE. With a small container of K1 and hose going to the fuel supply inlet.

      Powers up, igniter is getting hot, combustion fan does not come on, however it does get warm, turn freely by hand and there is voltage going to the combustion fan leads.


      Thank you.

      Comment


      • #18
        replace the combustion fan motor - $146.

        Comment


        • #19
          Originally posted by HayZee518 View Post
          replace the combustion fan motor - $146.
          Thanks HayZee, I thought this, the combustion fan, was the problem. 2 of the 4 wires going to the fan are separate, does their orientation matter, positive / negative.

          Thanks again.

          Comment


          • #20
            no orientation two wires are for the fan motor the other two are for the damper solenoid. only thing dc on the unit is the supply for the computer board.

            Comment


            • #21
              Thank you very much for all of your help sir.

              I have the service manual, however it does not specify certain things, hence the questions. Thanks very much for your help.

              Comment


              • #22
                Well, finally got the time to start putting the Monitor back together. There was about 3/4" of carbon build up in the burner pot where the k1 comes in. Man that stuff didn't go without a fight either. It was a combination of chiseling and the dremel that finally got it relatively clean. Just finished putting the burner mat in. I used some Permatex Ultra Copper for the glue. Im a little apprehensive though because on the back it says "not for surfaces in contact with gasoline". I also ended up having to basically smear the stuff all over my fresh burner mat in order to make sure all of the edges are glued down. I have no idea how this will effect the performance. As of now the glue has to cure overnight and hopefully it will get a test run tomorrow night.

                Here is a picture of what my glued down mat looks like.

                Comment


                • #23
                  MONITOR Burner mat

                  The way you got your burner mat is wrong! It's shaped like a D with the rounded part near the left rear side. the cut-out for the U shaped channel goes under the channel. your photo shows the mat covering the whole thing - not correct!

                  Comment


                  • #24
                    where are the three pins that the combustion ring goes on?

                    Comment


                    • #25
                      Permatex Ultra Copper

                      I tried using the Permatex Ultra Copper to hold down my original mat where it had come unstuck at one corner. The Permatex vaporized and the mat came unstuck again. I finally used Rutland Hi-Temp Stove & Gasket Cement, which seems to be holding so far.

                      Comment


                      • #26
                        The RUTLAND High temp cement requires heat to fully cure it - that's why I used it. Silicone products break down as you found out.

                        Comment


                        • #27
                          The way you got your burner mat is wrong! It's shaped like a D with the rounded part near the left rear side. the cut-out for the U shaped channel goes under the channel. your photo shows the mat covering the whole thing - not correct!
                          Hayzee I don't have a 441 I have an M22. Check out page 40 of the service manual, Fig. 5-1 is what I used for a reference.

                          where are the three pins that the combustion ring goes on?
                          I had to take them out to get my dremel in there to get all of the built up carbon out.

                          I tried using the Permatex Ultra Copper to hold down my original mat where it had come unstuck at one corner. The Permatex vaporized and the mat came unstuck again. I finally used Rutland Hi-Temp Stove & Gasket Cement, which seems to be holding so far.
                          Thats pretty crappy about the Permatex. I didn't read about the Rutland stuff until I had already glued it down. I did buy some of the burner mat and gasket material from McMaster Carr that Hayzee recommended though, so I guess I will tear out the other mat and replace it while its still apart and do it the right way.

                          Other than all of that stuff, did you guys end up smearing the cement all over the bottom of it or did you manage to get it in there with just a ring around the edges?

                          Comment


                          • #28
                            JUST A BEAD AROUND THE EDGES - THE CUT FLAP IN THE BURNER MAT SLIDES UNDERNEATH THE u SHAPED CHANNEL. YOU'LL NEED TO REMOVE THE FUEL TUBE AND FUEL TUBE EXTENSION TO GET THE MAT UNDERNEATH.

                            Comment


                            • #29
                              Ok, a little update: Between my very full time job and a few other winter projects I had laying around , I managed to get the monitor completely rebuilt and put back together. I ended up scraping the permatex in the burner pot and just used rutland cement, along with the burn mat material from McMaster Carr that Hayzee reccomends. I can say that the new burner mat material is nothing like the one you get from monitor, It feels much heavier, almost like canvas. It was much easier to work with as well. Hopefully it works as well as a burner mat as the OEM piece.

                              Second, I used the copper permatex for a lot of the gasket sealing surfaces, I guess we'll see how that turns out. It might not be able to take it.

                              So I got it back together and inside. Fired it up and it went though all of the purge steps and the the burner status lights would come on but the solenoid pump wouldn't do anything. AH, yes I thought to myself, this was the hole reason for me taking the damn thing apart in the first place. Once I found the huge amount of carbon in the burner pot, I assumed that was the reason for all of my troubles and everything would be perfect once I cleaned it out and but in a new burner mat. Well that was not the case, so I started hunting around. There was no voltage at the pump it self but there was voltage going into the pump controller. At this point I was pretty sure it was the air pressure switch or the pump controller itself. I decided to jumper the air pressure switch and volia, the pump kicked on when It was supposed to and everything seems to be timed and working like it should. I will be buying a new pressure switch the jumper was just for diagnostic purposes.

                              Now the problem, I don't know how to adjust the air fuel ratio. When it first fired up I had a pretty decent blue flame, but once it kicked in to high fire it was very orange with no blue to be seen. Is there a damper screw somewhere? Do I need a manometer to do this or can I just eyeball the flame and get close enough? I will also keep everyone posted as to how the permatex gaskets hold up.

                              Edited for spelling.

                              Comment


                              • #30
                                the shops around me just eyeball the flame. the unit needs to reach operating temperature before making any adjustment to the damper air. mpi recommends using a manometer. sources of the feeds to the "meter" is a screw hole where the heater bracket is and one hole by the viewing port.

                                Comment

                                Working...
                                X