Help!! 422 Not Heating Properly

[hawkins111]

You do not need to remove the tank to get the pump out, however you will need a bent screw driver to get the two screws out. I don't think there is anything wrong with the pump. Try to clean out the nozzle port into the burner.

[FordMan59]

The nozzle at the pot is clean. I removed the pot, cleaned it and put in a new burn mat last winter when the problem started. I've also taken the fuel line off and I can blow through it and feel air at the other end so I know it's not stopped up. The pump is the only other thing I can think of that could possibly be the problem, of course I'm not a Monitor technician so I could be wrong. If you have other ideas I'm interested in hearing them. I'd like to get this heater going so I could either put it back in service or at least have it working in case something happened to the one I have been using. The igniter is working so I know that's not the problem. All the gaskets related to the pot/heat exchanger that were disturbed were replaced. If you don't think this is a pump problem do you think it could be something going on with the circuit board? I've got some 90* screwdrivers somewhere but will have to locate them. I haven't used them for anything is so many years I don't even know which tool box their in now.

[hawkins111]

In my 15 years of fixing Monitor heaters I have never seen an out of spec pump on a 422 or 441. That being said, the pump could be bad. I have seen a couple of pumps that had burned wiring. Since the pump controller on a 422 is on the main circuit board it is a rather delicate operation to mess with. I have never attempted to adjust a Monitor fuel pump and don't recommend that approach. First of all you need to calibrate the pump. If you find the pump is out of spec., it could be the pump or the main board. The only way to end that dilemma is to change one or the other with a known good part. Kind of a PITA but that's what it takes. Monitor PC Repair can fix your board if that is the problem.

[FordMan59]

Thanks Tom. I've got both an extra pump and motherboard so I should be able to figure this out with a little work/time with no additional expense. Both of those parts are used. The pump was given to me and the motherboard was bought a few months ago off of eBay. When I get the chance to work on it and figure out what the problem is I'll report it here.

[FordMan59]

I haven't tested it yet but I think I found out what was wrong. I pulled the pump out of the constant level control valve and when I turned it upside down the filter on the bottom of the pump was full of sludge/dirt and probably wasn't letting enough fuel get to the pot to fire up and burn. I cleaned it the best I could with a paper towel, soaked it in vinegar for a couple hours and reinstalled it. I also took an eye dropper and sucked the fuel out of the constant control valve to be sure there was no water/trash in it. Guess I can't complain, it took 22 years of use and probably 2-3K gallons of fuel to get enough trash by the other filters to clog the filter on the bottom of the pump.

[FordMan59]

Success, I put the heater back in a few minutes ago. The first attempt it didn't start up so I thought I still had a problem. Checked everything out and found I'd forgot to plug the wires back on the fuel pump. Reset the heater tried again and it fired up first attempt. This time while I had the pot/chamber out I took the flame ring to a local welding shop and had them weld it all around the circumference and hit the clips that hold the ring in the pot with a little welding. I figure this will probably increase the life of the ring by many years since the welds will have to break before the ring can start to mushroom and flare out touching the flame detector rod.

Tom, another good way to get the screws out of the pump is put a 1/4" drive x 1/4" socket on a ratchet then put a screwdriver tip in the end of the socket. The screws on mine were at an angle that even with the 90* drivers I had things were still in the way of getting in the slots of the screws.

[ctbale]

If that pickup point was dirty there might be more dirt in the sump. Just by pulling the drain screw all the way out will get most of it out. And then clean the filter. I usualy pull the whole sump out. 2 wires, unhook the fuel tube, extend the heater leg, and it's just two screws and the sump come out on it's "tray"

I am rebuilding a 422 and the rings are $90 now! The one that was in there just has 3 of the 6 welds cracked, might try to find someone that does stainless to try to weld it too!

[FordMan59]

Those rings aren't made of stainless. Any wire welder should do the job just be careful welding it or you might burn a hole through the thin sheet metal. Getting mine welded and grinding down the welds smooth took about 15 minutes. I drained the sump and cleaned the filter prior to pulling the pump out, yet when I removed the pump and used an eye dropper to remove the fuel in the sump it picked up other trash and a little water out of the sump. Is it possible you could beat any edges that have turned out back down and have your old ring welded and keep it for a spare? The place I took mine to have it welded is just a small family owned business, they charged me $10. to weld it and grind it. I figure if it extends the life of the ring by 2+ years it will be money well spent.

[hawkins111]

You have stated in the past you use the capsule tank. Since you have had to service the constant level valve, I think you need to look at the fuel sump that is under the capsule tank. The sump has a stand pipe in it so it does not take fuel right off the bottom. Because the constant valve has dirt and water in it, the sump has got to have contamination.

Very few people use the capsule tank here in Alaska. They are a pain to use and end up smelling up the house. Storing and transferring fuel leads to contamination as well.

A siphon is a much better way to deal with that the sump. Taking it out is a real pain.

Tom

[FordMan59]

I cleaned that sump out about a year or two ago. There was lint and water in it at the time that had accumulated over the years but I think I got it cleaned pretty good. I have 4 capsule tanks that I keep filled all the time so when one runs dry I don't have to worry about refilling it right that minute if I'm busy with something else. With having 4 of the tanks even in the coldest weather we have around here I could probably go 2-3 days without having to worry about refilling any tanks before running completely out. When I lived in NC I had the heater piped to a 55 gallon drum and hopefully one day I'll get around to doing that here in KY.