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Troubleshooting: Burner runs continuously (too little heat).
Source
Procedure
Causes
Correction
Combustion
Check burner
combustion for
CO2, stack tem
perature, and
smoke
Low CO
2
less
than 10%.
Too much combustion air
Reduce combustion air.
Air leaks into heat exchanger
around inspection door, etc.
Correct cause of air leak.
Excessive overfire draft
Adjust barometric draft con
trol for correct draft.
Incorrect nozzle assembly
depth
Set to 1.13.
High smoke
reading more
than a trace.
Dirty or plugged heat exchanger
Clean heat exchanger.
Readjust burner.
Insufficient overfire draft
Increase draft.
Incorrect nozzle assembly
depth
Set to 1.13.
Too little combustion air
Increase combustion air.
High stack tem
perature is more
than 550
_
F Net.
Low volume indoor blower air
Check pump coupling for
wear / slippage.
Dirty heat exchanger
Clean heat exchanger.
Dirty burner blower wheel
Clean burner blower wheel.
Dirty furnace air filters
Clean or replace filter.
Restricted or closed registers or
dampers
Readjust registers or damp
ers.
Oil Pressure
Inspect fire and check
oil pressure.
Partially plugged or bad nozzle
Replace nozzle.
Oil pressure is too low
(less than 140 psi.)
Increase oil pressure to 140
psi.
