C42
Rev.304
TROUBLE SHOOTING SUGGESTIONS
GAS, OIL OR GAS/OIL BURNER
GENERAL
1. Burner Fails to Start
A. Defective On/Off or fuel transfer switch. Replace.
B. Control circuit has an open control contact.
Check limits, low water cutoff, proof of closure
switch and others as applicable.
C. Bad fuse or switch open on in-coming power
source. Correct as required.
D. Motor overloads tripped. Reset and correct
cause for trip out.
E. Flame safeguard control safety switch tripped out.
Reset and determine cause for apparent flame
failure.
F. Loose connections or faulty wiring. Tighten all
terminal screws and consult wiring diagram
furnished with the burner.
G. Frozen oil pump shaft preventing blower motor
operation. Replace oil pump.
H. Flame safeguard control starting circuit blocked
due to flame relay being energized. Possible
defective scanner--replace. Possible defective
amplifier--replace. Scanner actually sighting
flame due to leaking fuel valve--correct
unwanted flame cause. Defective flame
safeguard control--replace.
I. Defective blower motor. Repair or replace.
2. Occasional Lockouts for No Apparent Reason
A. Gas pilot ignition failure. Refer to pilot
adjustment section and readjust to make certain
that ignition is instant and that flame signal
readings are stable and above minimum values.
Use a manometer or 0 to 10" W.C. gas pressure
gauge on pilot test tee to make certain that
pressure is as recommended.
B. Check for proper settings on direct spark oil
ignition electrodes. Make certain that gap is not
too wide and that light-off oil pressure is as
recommended in Section 3.
C. Gas pilot ignition and direct spark oil ignition.
Verify that there are no cracks in the porcelain
and that transformer end and electrode end plug
in connections are tight.
D. Loose or broken wires. Check all wire nut
connections and tighten all terminal screw
connections in panel and elsewhere as
appropriate.
E. With flame safeguard controls that incorporate
the air flow switch in the non-recycling circuit,
ensure that when main flame lights, the air flow
switch is not so critically set as to allow
occasional momentary opening of the air switch
contacts.
F. Occasional low voltage supply. Have local utility
correct. Make certain that the burner control
circuit transformer (if supplied) is correct for the
voltage being supplied.
G. Occasional low gas supply pressure. Have local
utility correct.
H. Air leak in oil suction line or check valve not
holding. Correct as required.
GAS OPERATION
1. Burner Motor Runs, but Pilot Does Not Light
A. Gas supply to burner shut off--make sure all
manual gas supply valves are open. Automatic
high pressure valve at meter such as Sentry
type tripped shut due to high gas pressure--reset
valve and correct cause for trip out.
B. Pilot solenoid valve not opening--listen and feel
for valve actuation. Solenoid valve not being
powered--check electrical circuitry. Replace coil
or entire valve if coil is burned out.
C. Defective gas pilot regulator--replace.
D. Gas pressure too high or too low at pilot orifice.
Check orifice size in gas pilot assembly. Replace
if incorrect. Refer to gas pilot adjustments for
correct settings. Readjust as required.
E. Defective ignition transformer--replace. Incorrect
ignition electrode settings--refer to gas pilot
adjustments for correct settings.
F. Defective flame safeguard control or plug in purge
timing card. Replace as required.
G. Air flow switch not making circuit--check out
electrically and correct pressure adjustment on
switch if required. Defective air flow switch--
replace. Air switch negative pressure sensing
tube out of position--reposition as necessary.
2. Burner Motor Runs and Pilot Lights, but Main Gas
Flame is Not Established
A. Main shut off or test cock closed. Check to make
certain fully open.
B. Pilot flame signal reading too low to pull in flame
safeguard relay. Refer to gas pilot settings
section and readjust as required.
C. Defective automatic main or auxiliary gas shut off
valves. Check electrical circuitry to valves.
Replace valves or correct circuitry as required.
D. Main diaphragm shut off valve opening too slowly.
Adjust bleed on valve.
E. Defective flame safeguard control or plug in
amplifier. Check and replace as required.
F. Butterfly valve set incorrectly on modulating
burner. Readjust as required.
G. Main gas pressure regulator atmospheric vent line
obstructed. Correct.
H. Defective main gas pressure regulator--replace.
Misadjusted main gas pressure regulator--
readjust to meet required operational values.
3. Carbon Monoxide Readings on Gas Firing
A. Flame impingement on cold heat transfer
surfaces caused by excessive firing rate.
Reduce firing rate to correct input volume.
B. Flame impingement on cold combustion chamber
surfaces due to undersized combustion chamber.
Refer to chamber size charts, pages 14 and/or
contact factory for additional information.
C. Incorrect gas/air ratios. Readjust burner to correct
CO
2
/O
2
levels, reducing CO formation to appropriate
level. See NOTE on page 25 and page 41, Table 13
for additional information.
To Next Page
Loading...