3. TROUBLESHOOTING
The boiler is fitted with an electronic regulation and control unit. The heart of the control system is a microprocessor, the Comfort
Master©, which controls and protects the boiler and also protects the boiler. If a fault is detected anywhere in the boiler, the boiler
locks out and the display will show the fault code as follows:
In a red flashing display:
• The symbol
• The symbol RESET
• The fault code (for example E:01)
The description of each error code are given in the error table below. To reset an error code, press the
the error code continues to display, search for the cause in the error table and follow the instructions given in the solution section.
Error
Description
code
Storage unit PSU
E00
parameter not found
The safety parameters are
E01
incorrect
Supply temperature sensor
E02
short circuited
Supply temperature sensor
E03
open circuit
Temperature of heat
E04
exchanger too low.
Heat exchanger temperature
E05
too high
E06
Return temperature sensor
short circuited
E07
Return temperature sensor
open circuit
E08
Return temperature too low
E09
Return temperature too high
Temperature difference
E10
between the supply and return
E11
temperatures too great
Temperature of heat
exchanger is above the normal
E12
range (high- limit thermostat
STB)
7703476.01 (1-03/18)
Probable causes
Bad connection
Bad connection
PSU defective
Bad connection
Sensor fault
Sensor not/poorly connected
Bad connection
Sensor fault
Sensor not/poorly connected
Bad connection
Sensor fault
Sensor not/poorly connected
No circulation
Bad connection
Sensor fault
Sensor not /poorly connected
Bad connection
Sensor fault
Sensor not/poorly connected
Bad connection
Sensor fault
Sensor not/poorly connected
No circulation
Sensor fault
Sensor not/poorly connected
No circulation
Bad connection
Sensor fault
Sensor not/poorly connected
No circulation
12
button for 2 seconds. If
Checking / Solution
Check the wiring
Check the wiring
Replace PSU
Check the wiring
Check that the sensors are operating correctly
Check that the sensor has been correctly fitted
Replace the sensor if necessary
Check the wiring
Check that the sensors are operating correctly
Check that the sensor has been correctly fitted
Replace the sensor if necessary
Check the wiring
Replace the sensor if necessary
Purge the air in the heating system
Check for water circulation (direction, pump, valves)
Check the water pressure
Check that the sensors are operating correctly
Check that the sensors have been correctly fitted
Check the cleanliness of the heat exchanger
Check the wiring
Check that the sensor has been correctly fitted
Check that the sensors are operating correctly
Check the wiring
Check that the sensor has been correctly fitted
Check that the sensors are operating correctly
Check the wiring
Replace the sensor if necessary
Purge the air in the heating system
Check for water circulation (direction, pump, valves)
Check the water pressure
Check that the sensors are operating correctly
Check that the sensors have been correctly fitted
Check the cleanliness of the heat exchanger
Replace the sensor if necessary
Purge the air in the heating system
Check for water circulation (direction, pump, valves)
Check the water pressure
Check that the sensors are operating correctly
Check that the sensors have been correctly fitted
Check the cleanliness of the heat exchanger
Check that the heating pump is operating correctly
Check the wiring
Replace the sensor if necessary
Purge the air in the heating system
Check for water circulation (direction, pump, valves)
Check the water pressure
Check that the sensors are operating correctly
Check that the sensors have been correctly fitted
Check the cleanliness of the heat exchanger
Check that parameter P35 has been set correctly