Sterling SF User Manual
Page 24
24
Q. Cold air is delivered during
heater operation.
R. High limit tripping.
S. Power ventor will not run.
T. Power ventor turns on and off
during operation.
U. Power ventor will not stop.
1. Refer to “Gas Piping Requirements”, test and
reset manifold pressure.
2.
Refer
to
“Operation”.
1. Burner orifi ces may be too large, verify
and replace. Refer to “Gas Input Rate”.
2. Check for proper voltage, ensure fan
blade is correct.
3. Check operation of switch. If switch is open
during operation, check gas pressure; adjust
accordingly. If switch is open during start-up,
replace switch.
4. Check for 24V on line side of the high limit.
Constant voltage should be recorded. If not
control board is suspect. Check fl ash code.
1.
Check all wring in the power vent circuit to
ensure good connection, including “Neutral”.
2. Check for 115V between motor leads and
check amp draw of motor. Replace if needed.
3. Check for continuous 115V on terminal
“CBM Blower” and neutral during call for
heat. If not present and all checks are
normal, replace.
1. Check power ventor circuit per wiring
diagram.
2.
Check motor voltage and amp draw to motor
name plate, replace if motor found defective.
3. Check for continuous 115V on terminal
“CMB Blower” during call for heat, replace
board if found defective.
1. Check power ventor circuit per wiring
diagram.
2.
Heater is in lockout mode check fl ash code
table for problem.
3. No fl ash codes present along with no call
for heat, replace control board.
SYMPTOMS
POSSIBLE CAUSE(S)
CORRECTIVE ACTION
1. Incorrect manifold pressure or input.
2. Air throughput too high.
1. Unit is over fi red.
2. Air fl ow is low.
3.
Defective
switch.
4. Defective control board.
1. Loose wiring or connections.
2. Motor overload is tripped or bad motor.
3. Defective control board.
1. Power ventor improperly wired.
2. Motor overload cycling or defective motor.
3. Defective control board.
1. Power ventor improperly wired.
2. Main burner did not light on call for heat.
3. Defective control board.
Table 7 - Separated Combustion Tubular Propeller Troubleshooting Guide