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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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I have an oil Monitor 422 heater. I think that the flame rod

Customer Question

I have an oil Monitor 422 heater. I think that the flame rod sensor is bad. Can anyone provide me w/ a correct Monitor part number for it?I looked up the manual for the M-422 unit I found online which mentions 6118 (flame detective plug).
However the manual for the M-21 also has the same part number 6118 for this sensor.What troubles me is that the sensor for M-422 has a bent tip, whereas the M-21 is completely straight after the 90 degree elbow.Please help !
Submitted: 1 year ago.
Category: HVAC
Expert:  bonzaco replied 1 year ago.

The part that you seek is available from this company -- -- hope that helps the manual lists the 6118 as being the item for the 422 but I note that this supplier has it as 6186 maybe an upgrade/replacement. They are very helpful and worth a call if you are unsure - Ian

Customer: replied 1 year ago.
uhmm I think that's the wrong part number. 6186 is the room temperature sensor. I need the flame sensor.
Expert:  bonzaco replied 1 year ago.

Leave it with me - I'll check with them and come back to you later.