Installation and Maintenance Manual

28 GBNE-SVX001A-EN
Table 9 - Tubular Propeller Troubleshooting Guide (continued)
SYMPTOMS POSSIBLE CAUSE(S) CORRECTIVE ACTION
L. Blower motor
turns on and off
while burner is
operating.
1. Motor overload protection is tripping.
2. Loose wiring or connection.
3. Control board is defective.
1. Check motor amp against the motor name plate, check voltage,
replace if found defective.
2. Check for 115V between motor leads.
3. Check terminal ACB Heat for voltage. If voltage not constant,
replace board.
M. Blower motor will
not stop.
1. Control board is in flame failure mode.
2. Improperly wired blower circuit.
3. Control board is defective.
1. Turn 115V power off to the unit, wait 10 seconds and reapply
voltage to the unit.
2. Check wiring of blower circuit to wiring diagram.
3. If unit is not calling for heat and board is not in flash code
mode, replace board.
N. Not enough heat. 1. Incorrect gas input.
2. Heater undersized.
3. Thermostat malfunction.
4. Heater cycling on limit.
5. Incorrect orifice sizes.
1. Refer to "Gas Input Rate"
2. Is the heater output sized correctly for the heat loss of the
space? Has the space been enlarged? Is the heater located in
the space properly (see "Installation")?
3. Check thermostat circuit; 24V on terminals "R" and "W" on
terminal strip.
4. Check air movement across heat exchanger. Check voltage and
amps at the blower motor. Check gas input to ensure unit is not
over fired. Check heat exchanger to ensure unit is not dirty.
5. Check orifice size (Refer to "Gas Input Rate"), replace if
necessary.
O. Too much heat. 1. Unit is over fired.
2. Thermostat malfunction.
3. Heater runs continuously.
4. Defective gas valve.
5. Excessive gas supply pressure.
6. Excessive static pressure.
1. Refer to "Gas Input Rate." Check orifice size. Replace if too large.
2. Check thermostat for operation, to ensure circuit open and closes.
3. Check wiring per diagram. Check operation at the gas valve.
Look for a short in thermostat circuit.
4. Replace valve and check pressure setting (See Table 4 "Gas
Piping Requirements").
5. Refer to "Pipe Installation" and Table 4 - "Gas Piping
Requirements."
6. Adjust blower sheave to correct RPM - See "Blower Set Up and
Adjustment."
P. Noisy blower/
motor.
1. Blower wheel loose.
2. Blower wheel is dirty.
3. Blower wheel is rubbing on housing.
4. Bearings are dry.
5. Pulley is loose.
1. Replace or tighten.
2. Clean blower wheel.
3. Realign blower wheel.
4. Oil bearings on blower motor. (Refer to label on motor.)
5. Check Blower and Motor pulleys. Replace or tighten as necessary.
Q. Cold air is
delivered during
heater operation.
1. Incorrect manifold pressure or input.
2. Air throughput too high.
1. Test and reset manifold pressure (see Table 4 - "Gas Piping
Requirements").
2. Check Blower and Motor pulleys. Replace or tighten as necessary.
R. High limit is
tripping.
1. Unit is over fired.
2. Air flow is too low.
3. Defective high limit.
4. Defective control board.
1. Refer to "Gas Input Rate." Check orifice size. Replace if too large.
2. Check for proper voltage; ensure blower assembly is correct.
3. Check operation of switch. If switch is open during operation,
check gas pressure and/or CFM; adjust accordingly. If switch is
open during start-up, replace switch.
4. Check for 24V on line side of high limit. Constant voltage
should be recorded. If not, control board is suspect. Check
flash code.
S. Power ventor will
not run.
1. No power supply to unit.
2. Thermostat not calling.
3. Loose wiring or connection.
4. Motor overload protection is tripping or
bad motor.
5. Defective control board.
1. Turn on power supply, check fuses and replace if bad.
2. Turn up thermostat. Check for 24V on terminals R and W1 on
terminal strip.
3. Check all wiring in the power vent circuit to ensure good
connection, including "Neutral."
4. Check for 115V between motor leads and check amp draw of
motor. Replace if necessary.
5. Check for continuous 115V on terminal "CBM" Blower" and
neutral during call for heat. If not present and all checks are
normal, replace.
T. Power ventor turns
on and off during
operation.
1. Power ventor improperly wired.
2. Motor overload cycling or defective
motor.
3. Defective control board.
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 "CBM" Blower" and
neutral during call for heat. If not present and all checks are
normal, replace.
U. Power ventor will
not stop.
1. Power ventor improperly wired.
2. Main burner did not light on call for heat.
3. Defective control board.
1. Check power ventor circuit per wiring diagram.
2. Heater is in lockout mode; check flash code table for problem.
3. If no flash codes present along with no call for heat, replace
control board.
V. Noisy power
ventor.
1. Power ventor wheel loose.
2. Power ventor wheel is dirty.
3. Power ventor wheel is rubbing on
housing.
1. Replace or tighten.
2. Clean power ventor wheel.
3. Realign power ventor wheel.