29
6-563.7
servICe / mAInTenAnCe / TrouBlesHooTIng
Table 29.1 - Troubleshooting
TrouBle
PossIBle CAuse
PossIBle remedY
unit does nothing
1. Power supply is off
1. Turn on main power
(verify green light on
2. No 24V power to thermostat
2 a. Check control transformer
side of junction box
b. If failed transformer - check thermostat wire gage and length
is lit)
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 on ignition
1. Multiple causes
1. Control board LED flash codes vary with control type. A decal is
controller in main
installed in the unit giving a brief description of the applicable codes
control compartment
for your heater. For more detail, see the control board data sheet
off or flashing
included with this manual.
unit starts but does
1. Main gas is off
1. Open manual gas valve
not ignite (verify green
2. Air in gas line
2. Purge gas line
and amber lights on side
3. Main or manifold gas pressure
3. Set gas pressures per manual instructions
of junction box are lit)
4. Check gas valve switch
4. Set gas valve switch to "ON" position
5. Clogged condensate drain line
5. Check condensate drain line, clean as required
6. Tripped limit switch on power
6. Inspect and reset limit switch if no unit damage found
exhauster
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 than 10 seconds
3. Flame not sensed
3. Check flame sensing 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
