
KDB-GOM
Series
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6. Troubleshooting
6.1 Troubleshooting - Error Codes
Error Code
Cause
Troubleshooting
01 / Overheat
Clogged / Reduce flow in heating system
Circulating pump failure
Check strainer clean
Check system for air rate
Check pump for operation –220V AC = 1 Amp
02 / Low Water Level
No water in system / Pump failure
No make up water supply
Water fill valve failure
Check system / Check pump
Check system
Check system 5V DC- input signal
03 / Ignition Failure
Check ignition transformer
Check high limit switch / fuse
No gas supply
Air pressure switch tripped
Input 220V AC
N/C contacts
Check gas connection
Check gas valve
Check tube for connection
Check flue for blockage
04 / Flame Sensor
Low gas pressure
Fan failure / Airflow pressure switch
Check gas valve 220V AC
Check gas pressure
Check fan for operation
Check switch, flue for obstruction
05 / Heating Sensor Wire
Disconnected
Check molex connection
Re - connect
06 / Heating Sensor Short
Circuit
Sensor failure
Check voltage Pin #15&5 on 21Pin connector,
main controller 5V DC
07 / Hot Water Sensor Wire
Disconnected
Check molex connection
Re - connect
08 / Hot Water Sensor Short
Circuit
Sensor failure
Check voltage Pin #19&8 on 21Pin connector,
main controller 5V DC
09 / Fan RPM Failure
Fan failure
Check speed control
Check fan for operation. Input voltage 7 – 40V
DC. Red-Black wires
10 / Air Pressure Switch Failure
Fan failure
Air flow switch failure
Blocked flue
Excessive wind gusts
Check fan for operation
Check tube connection
Check voltage 5V DC
Check flue for blockage
Check flue termination - relocate
11 / Water level Detection
Failure
Check water fill valve
Voltage 5V DC
12 / Flame Failure
Low gas pressure
Fan failure / Air flow sensor
Blocked flue
Check gas pressure
Check gas valve
Check fan for operation
Check tube on air flow sensor
Check air flow sensor – 5V DC
Check flue for obstruction
13 / Heating Water Switch
Failure
Faulty switch
Check voltage – 5V DC on Pin #10 on 13 pin and
Pin #17 on 21 pin connectors
14 / Gas Alarm (Optional)
Check if connected (Red / Black wire)
Re – connect
Check gas supply
Check voltage 5 – 20V DC
15 / MICOM Failure
Check connection from t-stat to unit
Replace t-stat or micom controller
16 / Mechanical Overheat
Pump motor overheat
Fan motor overheat
Check for pump operation 220V AC, approx 1A
(dependent on flow rate)
Check fan for operation
Check rotation
17 / DIP Switch Setting
Incorrect settings
Check setting especially