L1: FLOW TEMPERATURE OVERHEAT LOCKOUT

L2: IGNITION LOCKOUT

LC: TURN POWER OFF AND ON

L6: FALSE FLAME LOCKOUT

F1: LOW WATER PRESSURE

F2 or Fn or Ln: FLAME LOSS

F3: FAN FAULT

L4 or F4: FLOW THERMISTOR FAULT

L5 or F5: RETURN THERMISTOR FAULT

F6: OUTSIDE SENSOR FAULT

F7: LOW MAINS VOLTAGE - CONTACT ELECTRICITY PROVIDER

F9 or L9 or F8 or L8: PCB UNCONFIGURED/FAULTY OR GAS VALVE SHORT CIRCUIT. SEE SECTION 3.19 IF FAULT PERSISTS REPLACE PCB

FA: NEGATIVE DIFFERENTIAL FLOW OR RETURN THERMISTOR FAULT

FU: DIFF GREATER THAN 50°C CHECK ISOLATION VALVES ARE OPEN CHECK PUMP CHECK RAD VALVES OPEN CHECK SYSTEM BLOCKAGE

dU: DIVERTER VALVE IN MID-POSITION FOR SERVICE ROTATE KNOBS FULLY CLOCKWISE TURN POWER OFF AND ON RESTART BOILER

NO CH BUT HW OK: SEEK HELP FROM EXPERT

NO HW BUT CH OK: SEEK HELP FROM EXPERT

NO DISPLAY: SEEK HELP FROM EXPERT