Posted by Rick Bullard on February 11, 2000 at 09:46:27:
In Reply to: boiler posted by Don on February 10, 2000 at 17:09:13:
: Today we had a boiler that had the o2 go from 4.2 to 9.2,also the sides of the boiler started pulsating. it was pulling about 40000. We have Preferred Instruments Controls.Any Help ?
The increase in O2 indicates an increase in excess air. I'd check the FD and/or ID fan controllers or the oxygen trim controller if you have O2 trim. The furnace was pulsating from an excessive amount of fuel-gas being carried through it.