Modine Manufacturing IPT Installation And Service Manual page 23

TROUBLESHOOTING
Table 23.1 - Troubleshooting
TROUBLE
Unit does nothing
LED light off or
flashing
Unit starts but does
not ignite
Unit goes through cycle
but the burners go out
in less then 10 seconds
Air circulating fan
inoperable
POSSIBLE CAUSE
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. Blown fuse on control board
2. Multiple causes
1. Main gas is off
2. Air in gas line
3. Main or manifold gas pressure
4. Check gas valve switch
1. Reversed main power polarity
2. Unit not grounded
3. Flame not sensed
1. Loose connections
2. Defective control board
3. Defective fan motor
POSSIBLE REMEDY
1. Turn on main power
2 a. Check control transformer
b. If failed transformer - check thermostat wire gage and length
3 a. Verify wire connections to R&W terminals only
b. Check / replace thermostat
4. Check LED flash code
5. Replace fuse
6. Replace control
1. Replace fuse
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.
1. Open manual gas valve
2. Purge gas line
3. Set gas pressures per manual instructions
4. Set gas valve switch to "ON" position
1. Black wire - HOT, White wire - NEUTRAL, Green wire - GROUND
2. Ground unit and verify quality of ground connection
3. Check flame sense probe and connection
1. Check all connections
2. Check control board data sheet and function
3. Check fan motor
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