Saunier Duval Isomax Condens F35 B 2 PCB Ref. 0020255376
RefurbishedSaunier DuvalPCBs (control boards)

Saunier Duval Isomax Condens F35 B 2 PCB Ref. 0020255376

3.100 €VAT included

PCB (control board): refurbished spare part that controls the ignition, modulation, and safety features of the boiler. Useful if the boiler does not ignite, locks up, or the display is unresponsive. Compatible with Isomax Condens F35 B/2, Isofast 21 Condens F35 B1 (ref. 0020255376). Includes a one-year warranty and delivery within 2–4 working days in the EU.

1
Consult via WhatsApp
Delivery in 2–4 working days
1-year warranty
14-day return
Technical support

Key Data

Reference
0020255376
Brand
Saunier Duval
Type of part
PCBs (control boards)
Status
Refurbished
Warranty
1 year
Shipping
2–4 working days (EU)
Return
14 days

The same part (ref. 0020255376) equips these models. Verified compatibility; check the reference before purchasing.

Isomax Condens

  • Isomax Condens F35 B/2

Isofast Condens

  • Isofast 21 Condens F35 B1

Fault codes related to this part (not the entire boiler). They usually have more possible causes: first rule out electrodes, wiring/connections, and gas supply. Verified with ≥3 sources.

CodeWhat does it mean?Cause and diagnosis (this part)
F.63EEPROM faultFault in the EEPROM memory integrated in the main PCB. Check supply voltages and, if the NTC sensors and wiring are correct, the PCB is responsible and must be replaced.
F.64Electronic fault / NTCIf the NTC flow/return sensors and their wiring measure correctly, the error is due to the NTC reading circuit on the PCB (analog input/5 V). Confirm by measuring the NTC at the PCB terminals; if the reading is correct and the fault persists, the PCB is defective.
F.65Fault: PCB temperatureThe electronics of the PCB reach excessive temperature (thermal condition or internal fault). Check ventilation/location and, if conditions are correct and it persists, replace the PCB.
F.67Fault: electronics/flameThe PCB does not interpret a plausible ionisation signal. After checking the electrode, cable, and earth connection, if the ionisation current is correct and the error persists, the fault is in the flame circuit of the PCB.
F.70Invalid product code (DSN)After replacing the display and/or PCB without recoding, or with incorrect coding resistance, the PCB ends up with an invalid DSN. Verify/correct product coding according to the installation manual (DSN adjustment) and, if it is not accepted, the PCB is either not suitable or is defective.
How do I know if this PCB is for my boiler?
Verify the reference 0020255376 printed and ensure your model is on the list of compatible ones; also compare the connections with the original part.
What is it used for?
The PCB controls the ignition, modulation, sensor readings, and safety features of the boiler.
Is the boiler not igniting, locking out, or is the control board unresponsive?
After ruling out mains voltage, fuse, and connectors, a damaged PCB causes lockouts, blackouts, or erratic display. Repair the external cause before installing the new one.
Which models is it suitable for?
Part shared by various models (see Compatibility). If your model does not appear, send us a photo of the marking and we will confirm it.
Installation and recommendations
After installation, a technician must adjust the service parameters (type of gas, power settings) and check combustion and safety features.
What does refurbished mean and what coverage does it have?
Part removed from a boiler out of service, inspected and tested. Includes 1-year warranty and 14-day return policy. Delivery within 2–4 working days in the EU.
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