Working on my Model 22

[LimeChild]

I have cleaned out the fuel sump. I have unscrewed the fuel line going into the burner and turned on the monitor no fuel comes out. Should it? I have removed the big fan behind the monitor and cleaned it.

When I turn on monitor the burner status light flashes 4 bars. After about 8 minutes all the status bars flash then R1(relay 1) snaps. This relay looks black on the cover. Could it be burnt out? If so how do I change it? The Base of the burner gets quite hot.

Any suggestions would be apperciated......

Thanks,
LimeChild

[HayZee518]

ok. unplug the heater then plug it back in. this resets the computer. merely shutting it off then on doesn't accomplish this. make sure there is fuel flowing into the sump tank. the black float will shut off the fuel flow when the tank is filled to about 3/4 inch from the top of the tank. with power on the unit, the combustion blower comes on and prepurges the combustion chamber, this takes about 300 seconds. all during this purge time, the igniter should be hot. you can tell this if the bottom of the heater is warm to the touch. you might see a glow in the pot when you look through that mica window. after 300 sec. the R1 closes and starts the fuel pump. If it is working you will hear a shallow thumping sound until the pump primes then it should get quieter. also fuel can be felt pumping if you put a finger or two on that copper cappillary tube. within a short time, all the permissives saying ok, the fuel should ignite. there should be a blue band of flame around the inside of the pot where the air holes are. the flame rod should detect the flame and keep the burner on. if it doesn't detect a flame after two tries it will shut off the fuel and flash all lights.

[LimeChild]

thanks

I have had it unpluged many times. I had the fuel sump apart this morning. I dosen't seem to be pumping. I can't hear it or feel it. Is there a way to test this? I think it is trying for the 300 seconds then timming out.

Thanks,
LimeChild

[LimeChild]

more troubleshooting

I took off the fuel line from pump to burner and snaked a piece of wire through it. I am not getting any power to the black wires comming off from the fuel pump.

The monitor that I have that works tested as followes. Black wires are hot once burner calls for fuel. There are 3 wires from board to pump. brown, blue and yellow. Blue is hot on low. Brown and blue are hot on high.

does this mean the pump is bad, or is something else on the circut board bad? I hate to pull pump off the good monitor and try it on the one that dosen't work...

Thanks for the help,
LimeChild

[HayZee518]

see if you have a voltage where the taisan pump controller connects to the motherboard. if you have 120 volts here then I would suspect the controller itself. you could take a resistance reading on the pump coil. if there is no voltage at the MB then next step in back tracking is the relay that closes and feeds power to the controller. I'll have to pull the schematic and do some checking.

[LimeChild]

I didn't check if it had power comming from the MB to the trans when it was calling for fuel. I will tomorrow.

Tomorrow im going to switch them out and see if that is the problem. I just hope I don't burnout the good one. You think that is possible?

Thanks,
LimeChild

[HayZee518]

Before I get going, take a look at a previous post. I included the names of four mpi distributorships. Two are in Maine, two are in NY.
OK, unless the MB is all messed up, you probably won't do any harm to the solenoid pump. Something really drastic has to happen to burn something out. MPI has a really good track record for dependability for its heaters. Hey you ought to take a look at Al Luce's site and how badly he bad mouths Monitors! He's a Maine resident too! MPI has a few choice words on him too. He's a self proclaimed guru on vented kero heaters. He practically remanufactured all the monitors ever made.

[LimeChild]

I saw the post with the parts reps in my area. I have a friend who owns a heating company. He owns it, he dosen't run it...lol I will see how much he can get the parts for once I figure out what parts I need. I am going to play with it somemore tomorrow.

I have read up on Al Luce's site. Had me scared for a while till I foound this forum.

Thanks for the help,
LimeChild

[LimeChild]

I switched out both parts of the Tasian pump and they worked fine in the other Monitor....Now it could be the fuel sump, or something in the mother board i guess....This is driving me NUTS....

LimeChild

[HayZee518]

if the pump worked in the other heater then the problem lies in the motherboard and the voltage path to the pump relay. don't let the machine drive you crazy. that's the worse you can do.

[LimeChild]

Well I guess its not the fuel sump either. I put mine in the other monitor and it worked. So i guess I need a new motherboard. Hayzee, any electricial things I can check to verify this?

Thanks,
LimeChild

[LimeChild]

Could it be the cookie shaped thing? I think its called the air pressure switch?

200 bucks for a used mother board....

I think im going to throw it in the trash...lol

[HayZee518]

when the unit is spinning up, the air switch should be closed. you can prove if this it by using a jumper cord with a couple of alligator clips on the two wires. if the unit starts you found the problem, if not then its a voltage path problem with the MB.

[LimeChild]

well it will have to wait a few days. Working 12hr nights.

[LimeChild]

I will have to take a picture so you can let me know which wires to jump. Maybe I can take one tomorrow afternoon.

when the unit is spinning up, the air switch should be closed. you can prove if this it by using a jumper cord with a couple of alligator clips on the two wires. if the unit starts you found the problem, if not then its a voltage path problem with the MB.