PCB Saunier Duval Isomax Condens F35 B-2 Ref. 0020255376
The PCB Saunier Duval Isomax Condens F35 B-2 Ref. 0020255376 is the component that controls the ignition, the modulation of the burner, the pump, and the safety features of the boiler. When it fails, the boiler may not start, become locked, or exhibit erratic operation. This part is compatible with models such as Isomax Condens F35 B/2 and Isofast 21 Condens F35 B1, among others. It is recommended to replace it when detecting operational issues or any faults related to the electronics, such as fault codes F.63, F.64, F.65, F.67, or F.70.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference 0020255376
PCB with reference 0020255376. Two confirmed compatibilities: Isomax Condens F35 B/2 and Isofast 21 Condens F35 B1.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval Isomax Condens F35 B/2 | Isomax Condens | Contrasted |
| Saunier Duval Isofast 21 Condens F35 B1 | Isofast Condens | Contrasted |
Can't see your model or have questions? The printed reference takes precedence. How to check it · Send us a photo via WhatsApp.
How to check if the reference 0020255376 is the part for your boiler.
What determines it is not the boiler model, but the reference printed on the part you already have installed.
- Find the reference printed on the installed part and check whether it matches the catalogue reference 0020255376. If it is not visible, do not identify the part from its shape alone.
- Check the full boiler model on its data plate and look for it in the model associations on this page.
- Compare the connections and physical body with the original part before installation.
- If anything is unclear, send us a photo of the marking via WhatsApp before placing your order.
Symptoms and faults that the PCB 0020255376 resolves.
The PCB controls the ignition, modulation, and safety features of the boiler. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The boiler is unresponsive: no display, no indicator lights, no remote control.
Cause: The PCB manages all the electronics of the unit, and a fault in it can render the boiler completely inoperable.
Check that the boiler has real power supply (main fuse, circuit breaker, network cable) before declaring the PCB faulty.
- 02
An error code appears on the screen that cannot be reset, or it returns as soon as it is reset.
Cause: The PCB interprets the signals from sensors and components; if the fault is in it, the error persists even if the rest of the system is functioning properly.
Note the exact code and check if it corresponds to a fault in the PCB or a specific component (sensor, pressure switch, gas valve) before replacing it.
- 03
The remote control or the panel do not respond to temperature changes.
Cause: The communication between the control and the control board goes through the PCB, and a fault there prevents the commands from reaching the burner.
Try to adjust directly from the boiler's own panel, without the remote control, to isolate whether the problem is with the PCB or the remote control.
- 04
The boiler works but in an erratic manner: it stops by itself, changes mode, or loses its programming.
Cause: Components of the PCB (relays, capacitors) can degrade and cause intermittent faults instead of a total failure.
Check if the erratic behavior coincides with power outages or humidity in the area before replacing the entire PCB.
Fault codes from Saunier Duval that this spare part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| F.63 | EEPROM fault | Fault 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.64 | Electronic fault / NTC | If 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.65 | Fault: PCB temperature | The 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.67 | Fault: electronics/flame | The 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.70 | Invalid 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. |
These symptoms can have more than one cause. If your boiler displays a fault code, send it to us via WhatsApp along with a photo of the labeling, and we'll tell you if this is the part.
Data sheet for the Saunier Duval PCB 0020255376.
- Catalogue reference
- 0020255376
- Brand
- Saunier Duval
- Type of part
- PCBs (control boards)
- Units in stock
- 1 unit
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- 1-2 business days
- Return
- 14 days
Data read on the part and in the manufacturer's documentation
What we have not been able to verify does not appear here.
- Internal name of the PCB (silkscreen)
- BMU 02 / PM-01
- Code on the white label of the PCB
- 0020204483
- Relay K111
- ZETTLER, 250V~10A / coil 24V DC (relay manufacturer, not the PCB)
Frequently asked questions about the PCB 0020255376
Is this PCB compatible with the Saunier Duval Isomax Condens F35 B-2?
What other models are compatible with this PCB?
What is the reference for the PCB of the Saunier Duval Isomax Condens F35 B-2?
What are the documented fault codes for this PCB?
How many models are compatible with this PCB?
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