Troubleshooting Chart (Truma Combi Furnace) - Truma CP plus Operating And Installation Instructions

Troubleshooting chart (Truma Combi furnace)

Error Cause
code
# 17 Hot water mode with empty water
container.
# 18 Warm-air outlet blocked.
Circulated air intake blocked.
# 21 Room temperature sensor/cable
defective.
# 24 Imminent undervoltage, battery voltage
too low < 10.4 V.
# 41 Electronics blocked.
# 43 Excess voltage > 16.4 V.
# 44 Undervoltage, battery voltage too low
< 10.0 V.
# 45 Only Truma Combi eco plus or Truma Combi comfort plus models.
No 120 VAC supply voltage.
Overheating protection has responded.
#112, Gas cylinder closed.
#202,
Switch for gas shut-off valve open.
#121,
Overheating protection has responded.
#211
#122, Combustion air infeed or exhaust gas
#212 outlet closed.
Switch for gas shut-off valve open.
Gas pressure regulation system
defective.
Overheating protection has responded.
Electronics defective.
#255 Furnace has no 12 VDC power supply.
No connection between the furnace and
the control panel.
Control panel cable defective.
If none of the measures in the troubleshooting chart proves successful or fault codes are displayed
that cannot be found in the troubleshooting chart, please contact the Truma Service Center at
1-855-558-7862 or one of our authorized service partners.
Remedy
Switch off furnace and allow to cool. Fill boiler
with water.
Check the individual outlet openings.
Remove blockage from circulated air intake.
Contact Truma Service.
Charge battery.
Contact Truma Service.
Check battery voltage and power sources,
such as battery charger.
Charge battery. If necessary, replace old
battery.
Restore 120 VAC supply voltage.
Contact Truma Service.
Check gas supply.
Close switch for gas shut-off valve.
Switch off furnace and allow to cool; if neces-
sary, fill the water container with cold water.
Check warm air outlets and circulated air in-
take and remove blockages.
Switch furnace on again.
Check for obstructions such as slush, ice or
leaves and remove from the openings.
Close switch for gas shut-off valve.
Contact Truma Service.
Switch off furnace and allow to cool; if neces-
sary, fill the water container with cold water.
Check warm air outlets and circulated air in-
take and remove blockages.
Switch furnace on again.
Contact Truma Service.
Ensure 12 VDC power supply.
Ensure connection between furnace and con-
trol panel.
Contact Truma Service.
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