Other Faults; No Heat (Central Heating) Fault Codes; Central Heating Does Not Reach The Correct Temperature - IBC SFC-99 Installation And Operating Instructions Manual

5.4 OTHER FAULTS

5.4.1 No heat (central heating) fault codes

POSSIBLE ANALYSIS
CAUSES
The power LED is not → Yes
shown.
↓No
The right display → Yes
shows a line (–).
The unit is off.
↓No
Room thermostat / → Yes
weather-dependent
control is not
connected
or is defective.
↓No
No electricity (24V). → Yes

5.4.2 Central heating does not reach the correct temperature

POSSIBLE ANALYSIS
CAUSES
Water pressure in the → Yes
system is too
low.
↓No
Room thermostat is not → Yes
calling for heat.
↓No
Temperature is set too → Yes
low.
↓No
No flow in the system. → Yes
↓No
The unit's capacity is → Yes
not correctly
set.
↓No
No heat transfer due to → Yes
contamination in the
central heating
↓No
unit/system.
Flue and/or air supply → Yes
duct is blocked.
5-8
SFC COMBI BOILERS SFC-99, SFC-125
POSSIBLE SOLUTION
•
Check the power supply.
•
Check the fuse (see Electrical schematic).
•
Check wiring for breaks.
•
Switch on the unit by touching just above the power LED and
holding for 2 seconds.
•
Check the wiring.
Check the OpenTherm, On/Off connection of the unit, or the
connection between the central heating unit and the
OpenTherm room thermostat. Replace the thermostat.
•
Replace the weather-dependent control.
•
Check the wiring according to the schematic.
•
Check Connector X13.
POSSIBLE SOLUTION
Top up the system.
Check the setting and adjust it if necessary.
Increase the central heating temperature (see central heating
demand). If an outdoor sensor is present. Check the outdoor sensor.
Check the ΔT ±36°F / ±20°C between the central heating supply and the
return. Ensure a correct flow in the system.
Adjust the unit's capacity.
Flush the central heating unit/system from the central heating side.
Check and (if necessary) clean the flue and the air supply duct.
INSTALLATION AND OPERATION INSTRUCTIONS