441 fuel pump issue

[Tolltech]

I have a monitor 441 I bought used. It hasn't been in operation for over a year. I have fueled it up but it will not ignite. The exhaust fan works, the fan pressure switch is working as well as the thermal safety cutouts that are in series with it. What I don't hear is the ticking of the sump pump. Using a DVM I did a voltage check on the pump leads and see there is none present. The ohms reading for the coil reads 535 ohms. What am I missing other than a component on the controller? I am a board level electronics technician with knowledge of component terminology. Before removing the controller board and tracing it out I’d like to know if there is a known relay or IC that could be a common fault to this failure?
Thank you
Raymond

[HayZee518]

on the motherboard is a taisin pump controller. it provides a pulsating 120 volts ac to the pump solenoid.

[hawkins111]

M441 fuel pump problem

Take the wires off the air safety switch and connect them together. They go through the over heat switches on the baffle (normally closed switches). This will by pass the air safety switch. You have already proved the solenoid pump. Try the stove, if it does not pump fuel send the circuit board to Mathis Electronics in NC. They will fix it for $100. You can’t beat that. The book says you need a high impedance DV meter to read the pulsing voltage. Since the stove is used be ready to overhaul the burner when you get the pump working.

Keep us posted,

Tom

[Tolltech]

Thanks for the info. Tom
I tried that procedure earlier tonight with no results but in reality it was a result in elimination. From there I just shorted the “J” connector on the board. I found that that completes the circuit to power the D2 bridge rectifier that in turn powers the pulse generator to fire the pump. I think the problem is with IC11. There should be ac power coming from that chips pin 13 but all I’m getting from it is about 11VAC where I believe it should be close to line voltage. When I verify this I’ll update the thread.
Thanks
Raymond

[dfitz3390]

did you have 160vdc at D2 ?

[Tolltech]

160VDC pump pulse

I don't have the 160VDC at D2 or 120 at its input. I was able to trace out the flow and found the problem to be IC11. Its a triac SSR that feeds through the air flow switch and thermal safety switches. I have voltage going in but none on its output. I'm ordering two of them Monday.
I'll be sure to post my results once I replace it.

Thanks

Raymond

[adnadeau]

IC11 voltages

Have you checked the control circuit of IC11? The spec sheet for the S101D01 shows forward voltage to the internal IRED (pins 2 & 3) to be 1.2V @ 20ma typical. That would put the voltage drop across R53 at around 11.2V. Q11 supplies voltage to IC11 and IC6 supplies the ground.

[Tolltech]

Thanks for the very helpful info.
I'm working without any prints and drawing them as I trace out the paths for the pump using the spec sheet for the S101D01. The diagram you sent was very helpful and I'm looking forward to using it later this evening. I'll post my results later this week.
Thanks again
Raymond

[adnadeau]

Here's the rest of the schematic in zipped format. Even PDFs are too big for the forum to handle.

[Tolltech]

adnadeau I thank you!

I should now be able to figure this out once I get back into it.

Thanks again
Raymond

[hawkins111]

M441 circuit board

Tolltech,

Have you had a chance to work on your main board?

Tom

[Tolltech]

Finnaly up and running

After reviewing the prints and documentation I have received from all the generous responders I found the time Friday night to dig in deep. Well I found three things that were not what I had expected. First, after I determined I had power pulsing to the known good coil ( tested at 535 ohms ) I concluded the pumps piston must be stuck. I took it apart and cleaned it out. Now I have fuel coming out from the top but not through the tube. I Cleaned out the tube. We have ignition! Now we don’t. Long story short we fast track 90 minutes. Found the flame sensor was not operating correctly. I installed the 1n4004 diode and 100k resistor across the ground and sensor input to verify the board components were functional. I removed the sensor and cleaned the excess carbon from it. Took off the sight glass and to the best aligned it per manual instructions.
It fired up and now it progresses through the normal sequences and levels off to a low burn. I’ve tried it from power down to forced power failure and so far it’s worked like a charm. Thanks to all who have helped. Just in time for that big whopper of a storm that came through yesterday. Now if I could only get my power back !!!!!!!!

Thanks
Raymond