[pjac]

The squirrel cage is tight on the motor shaft, but could be a bit off center of the flame tube. Would this cause the heater to rumble when it is ignited?

[KC13]

Are you referring to the indoor air circulating blower, or the combustion draft inducer (if present/equipped)? Brand/model# of unit would be helpful. If the rumbling starts after the circulating blower starts, heat exchanger leakage/failure is likely.

[pjac]

Hello KC13, Thanks for responding. I believe the combustion draft inducer is the one. The heater is a York model #UFO85D10. Someone delivered some bad fuel and this started the whole thing. I cleaned the heater, removed the pump motor and cage and cleaned that. I had another cage in much better condition, so I replaced the one that was on the pump motor. It rumbles and sputters somewhat, at start-up, then seems to work itself out. I thought I may have that draft inducer(cage) too far left or right on the shaft and it may be causing the flame to sound strange. Hope this makes some sense. I am more a car mechanic than heater mechanic and only involved in this due to current economics. Thanks, Pat

[KC13]

If this is a fuel oil furnace, the "bad fuel" may have fouled the burner nozzle. If a barometric damper is present, peek inside the flue with the burner running - use a flashlight. If smoke is visible in the flue, the fuel may not be properly atomizing.