I have a suburban furnace in my '77 that had a hard time firing, so I took it apart and found the cast iron burner to be clogged with rust about 30% of the slots. (a hacksaw blade fits in the slot perfectly for those trying to clean out theirs) I adjusted the screw which moves the baffle on the inlet and was wondering what the best procedure for the adjustment is. I think I have it too lean, as sometimes it "pops" a little when it fires, and other times it doesn't catch at all and will just blow cold until you reset the thermostat.

Don't mess with refurbing a burner - this goes also for the reefer and the hot water heater. Replace it!

That rust came from somewhere in the burner structure, weakening it, or there are clumps of rust plugging the gas path causing the popping - that symptom is not one to live with (figuratively and literally).

Do the adjusting with the new burner (chances are it won't need much).

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Rusty

StaRV II, '94 28' Breakaway, 6.5L TD
2 Not-spoiled Golden Retrievers.

[This message has been edited by Rusty (edited February 11, 2006).]

there is no foreign material blocking the gas flow, it it clean. The wall thickness of that part is overkill and that little scale won't comprosmise its integrity. I have magnafluxed it on a wet bench it is not cracked. I'd like to know the procedure for adjusting the flame regardless if the burner log is new or used. ie. Should the flame be more blue or more orange? Is there a nominal settting, as in number of turns from fully closed or fully open?

Generally speaking, you've got it adjusted properly when the blue part of the flame is seated on the burner without gaps, and the flame tips have an occasional flicker of yellow or orange.

If the base of the flame leaves the burner, there's too much air. If the flame has too much yellow or orange, there's too little air, and you're generating soot.

Your furnace manufacturer may have different advice, but that's what my water heater instructions said many years ago.

Thanks olroy, that is exactly the help I was looking for.

Cast iron should last just about forever - the burner in my SOB appears to be stamped metal (from the prints - I've not had it apart).

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Rusty

StaRV II, '94 28' Breakaway, 6.5L TD
2 Not-spoiled Golden Retrievers.