Compact Unit Heater
17
Operating Instructions and Owner’s Manual
Symptom
Possible Cause
Possible Remedy
Unit does not Start
1. Power supply is off.
2. No 24V power to thermostat.
3. Thermostat malfunction.
4. LED flashes.
5. Blown fuse on control board.
6. Defective control.
1. Turn on main power.
2. Check control transformer.
a.
If failed transformer – check
thermostat wire gage, length, and
defects.
3. Verify wire connections to R&W terminals
only.
a. Check/replace thermostat.
4. Check LED flash codes located on decal in
the unit or Table 10.
5. Replace fuse.
6. Replace control.
LED Light Off or Flashing
1. Blown fuse on control board.
2. Multiple causes.
1. Replace fuse.
2. Control board LED flash codes vary with
control type. A decal is installed in the unit
and Table 10 gives a brief description of the
applicable codes for your heater.
Unit Starts but Does Not
Ignite
1. Main gas is off.
2. Air in gas line.
3. Main or manifold gas pressure.
4. Check gas valve switch.
1. 1. Open manual gas valve.
2. Purge gas line following the necessary
precautions.
3. Set gas pressures per manual instructions.
4.
Set gas valve switch to “ON” position.
Unit Goes Through Cycle
but the Burners Go Out in
Less than 10 Seconds
1. Reversed main power polarity.
2. Unit not grounded.
3. Flame not sensed.
1.
Black wire – HOT, White Wire – NEUTRAL,
Green Wire – GROUND.
2. Ground unit and verify quality of ground
connection.
3. Check flame sensor probe and connection.
Air Circulating Fan
Inoperable
1. Loose Connections.
2. Defective control board.
3. Defective fan motor.
1. Check all connections.
2. Check control board data sheet and
function.
3. Check fan motor.
TROUBLESHOOTING
