Munchkin

Munchkin issue

I went to a customers house early this morning for a no heat call. I was there yesturday mourning for the same problem. The unit is a Munchkin 140M for radiant floors, baseboard and hot water. The fault was an F09 not sensing flame. The unit would start up and ignite but the flame would go out 2 seconds later. I removed the flame sensor clean it off and it fired off and went through a couple of cycles. I went to the supply house and got a new igniter and flame sensor and replaced both. I then adjusted the unit to manufactures recommended settings. It could of used a cleaning but they had heat for now and I scheduled it for Friday. 2AM this morning I get the call that the unit is not working F09, this time I can't get it to fire off. I check everything and cleaned the unit still nothing. So I recheck the wire connections and the ground wire connection for the flame sensor desintigrated. I installed a new groud wire and the unit fired off going through many cycles. There is alot of corrosion on the wires inside the boiler but none out side and no leaks inside. I have to go back and replace all the wires on the unit. The home is 4 years old and near the ocean (across the street). Has anyone seen this problem and/or does anyone have any suggestions? I thought about removing fresh air intake from out side, but waiting to hear from HTP and local Gas inspector. Would appreciate any help.

someone else had this problem

and it was the burner mounting screws were corroded. The grounding of the burner is such that the screws are the only way the burner ground path can happen. When they corrode, no path even though the wire is ok.

I will see if I can find the threaad.

Mitch

corrision

While you have the cover off have you also noticed rusting on the steel gas line if so then all the corrision may be from recirculating flue gas ,i would check the outdoor termation kit if used or the distances from inside ,outside and ground level to determine if this is what 's happening peace and good luck clammy