73
13 - TROUBLE SHOOTING
Error Code Table
Error
Code
Description
Probable Causes
Checking/Solution
E37
Communication error with
SU PCB
Bad connection
Check whether the SU PCB has been correctly fitted in
connector on PCU PCB
E38
Communication error with
SCU PCB
Bad connection
Defective SCU PCB
Check the wiring Replace SCU PCB
E39
Shutdown input in locked-
out mode
Bad connection
External problem
Parameter incorrectly set
Check the wiring
Find external problem
Check the parameters (CHART 8)
E40
HRU unit test error
Bad connection External
problem Parameter incorrectly
set
Check the wiring
Find the external problem
Check the parameters (CHART 9)
E41
No water temperature
change during deaeration/
air purge
Bad connection
Supply/Return sensor
damaged
No water circulation
Check the sensor connection
Replace sensor
Check the pump connection
E42
Low water cutoff
disconnected or water
pressure too low
Bad connection Water
pressure low
Check the wiring
Refill the system
Check for leaks (CHART 10)
E43
No water temperature
change during boiler
operation (burner on)
Bad connection
Supply/Return sensor
damaged
No water circulation
Check the sensor connection
Replace the sensor
Check the pump connection (CHART 11)
E44
Difference between supply/
return temperature too high
Bad connection
Supply/Return sensor
damaged
No water circulation
Check sensor connection
Replace sensor
Check pump connection
13.2
Shutdowns and Lock-outs
Blockage
If a blockage condition continues to exist after several start
up attempts, boiler will switch into lock-out (fault) mode. The
boiler can only start operating again once cause(s) of the lock-
out have been rectified and after pressing
button.
Lock-out Mode
A temporary lock-out caused by an unusual occurrence in the
boiler's operation. e.g. Display gives code of blocked flue
(code St9). Boiler control will try to re-start several times.
Boiler will start up again after blocking condition(s) have been
eliminated.
Shutdown codes can be read out as follows:
• Press the two buttons
simultaneously.
•
Confirm by pressing
button.
"St"
is displayed,
alternating with the shutdown code
"9"
.
• Press the
(+)
button.
"Su"
appears on the screen.
Boiler will start again automatically when reason for blocking
has been removed.
P/N 240011654, Rev. C [06/08/2017]