23
9-511
Table 23.1 - Troubleshooting
TROUBLESHOOTING
TROUBLE
POSSIBLE CAUSE
POSSIBLE REMEDY
Unit does nothing
1. Power supply is off
1. Turn on main power
2. No 24V power to thermostat
2 a. Check control transformer
b. If failed transformer - check thermostat wire gage and length
3. Thermostat malfunction
3 a. Verify wire connections to R&W terminals only
b. Check / replace thermostat
4. LED flashes
4. Check LED flash code
5. Blown fuse on control board
5. Replace fuse
6. Defective control
6. Replace control
LED light off or
1. Blown fuse on control board
1. Replace fuse
flashing
2. Multiple causes
2. Control board LED flash codes vary with control type. A decal is
installed in the unit giving a brief description of the applicable codes
for your heater. For more detail, see the control board data sheet
included with the unit.
Unit starts but does
1. Main gas is off
1. Open manual gas valve
not ignite
2. Air in gas line
2. Purge gas line
3. Main or manifold gas pressure
3. Set gas pressures per manual instructions
4. Check gas valve switch
4. Set gas valve switch to “ON” position
Unit goes through cycle
1. Reversed main power polarity
1. Black wire - HOT, White wire - NEUTRAL, Green wire - GROUND
but the burners go out
2. Unit not grounded
2. Ground unit and verify quality of ground connection
in less then 10 seconds
3. Flame not sensed
3. Check flame sense probe and connection
Air circulating fan
1. Loose connections
1. Check all connections
inoperable
2. Defective control board
2. Check control board data sheet and function
3. Defective fan motor
3. Check fan motor
