Ignition question

[johnrock11j]

Intertherm Model# M1MB 07A BW.
When it starts to ignite it clicks of and on 2,3 and sometimes 4 times really fast before it finally stays lit. What would cause this?

[Robert]

Trace two wires from ignitor to their connection with either two more wires or at a plug connector.

Disconnect, run a cycle and at appropriate time, see if ignitor is getting 120VAC continously for about 30 seconds or so.


Also, check burner orifice for blockage from spider/web possibly.


Thanks,
Robert

[johnrock11j]

I checked ignitor at connector and it stayed at 118.5 most of the time and then jumped to 120.8 and stayed for close to 30 seconds but not any more than 30.

[Robert]

Hi,


Turn power off, disconnect ignitor wires, trace two power wires back to molex plug on circuit board.


Determine where the two wires are in plug, unplug the connector and place meter leads on the pins for ignitor power wires.


Turn power on, call for heat at heat-auto-85* and see if voltage fluctuates with clicking sound.



Thanks,
Robert

[johnrock11j]

Robert,
The ignitor seems to hold around 120.2 to 120.4 volts but doesn't fluctuate when the clicking occurs. When I place the meter on the gas valve terminals the readings fluctuate so fast that I can't keep up with reading them.

[Robert]

Hi,

Trace them back to board and do same as before with ignitor wires to see if the voltage fluctuates at the board connection to gas valve with the clicking sound.


Sounds like a board relay opening and closing.



Thanks,
Robert

[johnrock11j]

Robert,
When I place the meter on the gas valve pins at the circuit board the vac fluctuates like I said before.

[Robert]

Hi,

It fluctuates 3 or 4 times and then eventually sends 24vac to gas valve ?


If so and there is 24vac at W and C always and the two wires from pressure switch at molex plug BOTH pins read 24vac each to ground, the board is bad.



Thanks,
Robert

[johnrock11j]

I you are talkig about the two terminals marked c and w they have a little more than 26 vac and when it starts clicking it does drop some but never under 24 vac.

[Robert]

Hi John,

You should first get 24-27vac at W and C. Then the booster/combustion motor should run.

When/if it reaches correct w.c. pressure to close pressure switch, follow two wires from pressure switch back to molex plug on board (9 pin).

See if the corresponding pins from board read 24vac each to ground.

If so, pressure switch closed and voltage should go to ignitor, then gas valve after 30 seconds or so.


Sounds like all of this happens, but the 24vac to gas valve fluctuates and clicking is heard from board relay to GV.


If so, the circuit board is bad.


Do you need ordering info ?



Thanks,
Robert

[johnrock11j]

Robert,
Everything vac look good other than to the gas valve. It is clicking in the circuit board and the gas valve 3 or 4 times before lighting. It sounds to me that Im going to need ordering info.

[Robert]

Hi,

Integrated Control Board # 903429 can be seen and ordered

through PayPal from left side of page here :


http://www.mobilehomerepair.com/NordyneGas.html



Thanks,
Robert

[johnrock11j]

Robert,
Installed the control board today but no change. I have noticed that it was starting to click more before I put the control board on. When it clicks the first time it actually ignites and continues to click off and on very quickly before staying lit. What are the symptoms when the gas valve goes bad?

[Robert]

Hi,

If your gas valve has correct inlet gas pressure and 24vac at GV terminals, but does not have correct manifol gas pressure it is bad.


This could be the ignitor, have you placed an ammeter on it to see what the amp draw is ?


There are a few clicking sounds that can come from within a small area, so w/o being there to test and hear, can be hard to pin down.



Disconnect the ignitor wires and set t-stat for a call for heat and see if you hear the clicking sound.

It is usually the control board, ignitor or gas valve when that happens.


Thanks,
Robert

[johnrock11j]

Robert,
The clicking is the gas valve itself. I just replaced the ignitor this winter. As for the amp draw I'm not sure what you mean. The gas valve has 26.61 vac and the ignitor has 121.1 vac. Now the good news is that starting late last night it started working fine and has continued to do so. I have no idea what this things problem is. As for the gas pressure I just had the gas company test there line pressure and mine and replace the meter and regulator.