INSTALLATION AND OPERATION INSTRUCTIONS
5-10
SFC COMBI BOILERS SFC-99, SFC-125
POSSIBLE CAUSES
ANALYSIS
POSSIBLE SOLUTION
Central heating pressure is too low.
→ Yes
↓No
Top off the central heating system until the central heating
pressure is between 1 and 2 bar.
The flue is blocked.
→ Yes
Check the flue.
5.4.6 Burner ignites loudly
POSSIBLE CAUSES
ANALYSIS
SOLUTION
Inlet pressure is too high.
→ Yes
↓No
The home pressure regulator may be defective. In that
case, contact the energy company.
Ignition distance is incorrect.
→ Yes
↓No
Replace the ignitor including the ignition cable.
Gas-air control is not correctly
adjusted.
→ Yes
Check and/or replace the ignition cable.
Replace the ignition unit in the top cover.
Replace the ignitor.
5.4.7 Burner resonates
POSSIBLE CAUSES
ANALYSIS
SOLUTION
Gas inlet pressure lower than 5“ w.c.
or sometimes disappears.
→ Yes
↓No
The home pressure regulator may be defective. Contact
the energy company.
There is recirculation of flue gases.
→ Yes
↓No
Check the flue and air supply duct.
Gas-air control is not correctly adjusted.
→ Yes
↓No
Check the adjustment
Burner seal is defective.
→ Yes
↓No
Replace the burner seal.
Burner is defective.
→ Yes
Replace the burner.
