Munchkin F9

ChrisL

I have a Munchkin 140M locking out on F9. Its been working fine for 1 1/2 yrs, and now it locks out on F9. On reset, it sometimes works. Otherwise it lights, and then turns off after 3 seconds or so. I cleaned flame sensor and get 2.7-3.6 mvolt from vision display.

Thanks,

ChrisL

Mark Custis

What is

F9?

S Ebels_2

Burner failed to light

If the unit has been in service for that length of time you need to pull the burner and clean the combustion chamber. it's probably loaded with debris and residue which impedes fuel/air flow and plugs the condensate drain. Really not a bad task if it was set up right by the installer. Have a new target wall and refractory on hand as these have usually degraded by the time the unit has backed up condensate in the combustion chamber. Annual maintenance will usually avoid these lockouts in the middle of winter.

tim smith

I second steve's reply, also make sure to have new burner

flange gasket and clean flange surfaces and nuts that mount flange with find emery cloth. This is the ground path for flame sense and can be a nuisance. Tim

Derheatmeister

I Third that also check for a Proper Ground on the Terminal Grounding Block which i have seen Corrode and the loss of contact.

cattledog

FO9 code

Had this very same problem with one of my tenants heat. Had the service man by, he traced the problem to no gas supply. The gas meter for that apt. was faulty/frozen. The gas co replaced the meter, OK. HOWEVER! The gas service man accidentally got water inside the 80M. How I still cannot figure out. Shorted out both the draft fan and main control boards. He was gone when I checked this. This required a return visit from the Munchkin service man. $1000.00 later the boiler is running. I am calling my lawyer this morning to see what I can do, but I think chances for the gas co service man to admit even a honest mistake, is zero.

The dust hasn't settled yet!