Table 5-1. Troubleshooting - Continued
2. Low fire switch closed, burner
does not ignite - Continued
e. Fuel valve or lines restricted or
e. Disconnect fuel tubing to burner at
burner. Turn low fire switch on and
observe fuel flow from line. Visually
inspect fuel lines for leaks or
crimping. Disconnect fuel supply line
from pump to fuel valve at valve,
observe fuel flow from line. Replace
or repair fuel line as necessary.
f. Fuel valve solenoid coil loose or
burned out (open).
f. Check tightness of coil retaining nut.
circuits 6 and 2 (high fire) or 7 and 2
(low fire) to solenoid coil from lower
continuity across the coil. If coil
shows open, replace coil.
g. Flame failure lockout.
g. Red flame failure light on. Deter-
mine cause of flame failure, see
malfunction 8. Flame signal below
2V DC. Remedy cause and depress
failure reset button before restart.
h. Flame safeguard contacts dirty.
h. See service of flame safeguard. Use
a burnishing tool or fine crocus cloth
to clean contacts. Never use a file or
sandpaper to clean contacts.
i. Defective ignition transformer.
i. Low or zero voltage between control
circuits 4 and 2 at control terminal
board. Check for loose or broken
conductor in circuits 4 and 2 to
transformer. Repair or replace as
necessary. Remove electrode wires
from burner and hold terminals 1/8-
inch apart. Turn on low fire switch
and observe if an electrical arc
develops between electrode wire
terminals. If electrode wires are good
(see step m) and there is no arc,
check continuity across transformer
secondary. Replace as necessary.
j. Wire loose or broken.
j. Check conductors of control circuits
3 and 1 from control terminal board
to low fire switch and limit switches
for tightness and continuity. Check
conductors of control circuits 1, 2, 3,
4 and 7 from control terminal board
to flame safeguard terminal board for
tightness and continuity. Tighten,
repair or replace conductors as
k. Low fire start switch defective.
k. See malfunction 1, step h.
l. Electrode wires loose, broken,
disconnected or shorted.
l. Check terminals for tightness at
ignition transformer and burner.
Observe that terminals are not
metallic parts or burner. Check wires
for continuity. Tighten, repair or
replace conductors as necessary.
m. Electrodes out of alignment.
m. Remove burner and check that gap
of electrodes is adjusted to 1/16 to
ignition transformer and cycle low
fire switch. Observe spark is suf-
ficient to light burner.