7 Error codes
Operation manual
11
D2C20ND0 D2C24ND035A5AA
Wall-mounted condensing boiler
3P469438-10H – 2018.05
#
Problem
Solution
8H-64
Flow temperature
steep rise
Make sure radiator valves are open
enough to circulate water. Your
boiler will operate again after a while.
If problem repeats, contact your
service agent.
8H-65
Flow-return
temperature
difference too much
Make sure radiator valves are open
enough to circulate water. If problem
repeats, contact your service agent.
E1-64
Flame detection
before burner
operation
Perform reset. If problem repeats,
contact your service agent.
E1-65
Internal SCOT
system error
Perform reset if needed. If problem
repeats, contact your service agent.
E1-66
Calibration conditions
fault
No reset needed. Wait burner to
restart. If problem repeats, contact
your service agent.
E1-67
Missing calibration
Perform reset. If problem repeats,
contact your service agent.
E1-68
Ion base value is
outside the factory
limits or saved
incorrectly
Perform reset. If problem repeats,
contact your service agent.
E1-69
Parameter CRC error Perform reset. If problem repeats,
contact your service agent.
E1-70
Parameter CRC error Perform reset. If problem repeats,
contact your service agent.
E1-71
EK lockout failure
Permanent error. Contact your
service agent.
E1-72
SCOT flame amplifier Perform reset if needed. If problem
repeats, contact your service agent.
E1-73
Internal PCB error
Perform reset if needed. If problem
repeats, contact your service agent.
H9-01
Outside sensor fault
Boiler continues operation but
outside sensor is defective. Contact
your service agent.
HC-01
Domestic hot water
temperature sensor
fault
Boiler continues operation but you
must contact your service agent.
HJ-08
High system pressure Discharge water down to 0.8 bar.
(You can bleed the radiators.)
HJ-09
Low system pressure Increase the system pressure to
0.8 bar
HJ-10
Water pressure
sensor fault
Contact your service agent.
J6-01
Flow temperature
sensor overheating
(Can be a blocking
error or a lockout
error)
▪ Check the valves of the radiators
in the heating circuit.
▪ Check the combi boiler water
pressure. If it is low, fill the heating
circuit with water.
▪ Perform reset if needed. If problem
repeats, contact your service
agent.
J6-20
Return temperature
sensor overheating
(Can be a blocking
error or a lockout
error)
Perform reset if needed. If problem
repeats, contact your service agent.
J6-21
Return temperature is
higher than flow
temperature
No reset needed, burner operates
itself after a small amount of time. If
problem repeats, contact your
service agent.
JJ-64
Flue temperature
sensor fault
Perform reset. If problem repeats,
contact your service agent.
#
Problem
Solution
U2-01
Supply voltage is
below low limit
Contact your service agent.
U2-01
Supply voltage is
above high limit
Your boiler will continue operation
but you must contact your service
agent.
U4-65
Opentherm room
thermostat
connection is
defective
Your boiler will continue operation
but Opentherm room thermostat is
out of operation. Contact your
service agent.
U4-66
CAN-bus timeout
If problem repeats, contact your
service agent.
U4-67
Remote reset
supervision
Switch off - switch on power mains. If
problem repeats, contact your
service agent.
UA-64
Blocking during BCC
update process
Contact your service agent.
UA-65
PCB requires a BCC
update
Contact your service agent.
UA-66
BCC-ID of internal
EEPROM is
inconsistent
Contact your service agent.
UA-67
BCC is missing
Contact your service agent.
UA-68
BCC is not
compatible with PCB
(BCC-ID)
Contact your service agent.
UA-69
BCC is not
compatible with PCB
(firmware)
Contact your service agent.
UA-70
BCC update error
Contact your service agent.
UH-08
Date and time are not
set
If energy metering function is
interrupted or not started, date and
time must be set to resume. Set the
date and time from t parameters
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