Saunier Duval Combitek F 23 PCB Ref. 8/050149
The control PCB of the Saunier Duval Combitek F 23 boiler manages the ignition, burner modulation, pump, and system safety features. When it malfunctions, the boiler may fail to start, lock out, or operate erratically, displaying fault codes such as F.63, F.64, or F.28. This part is compatible with models from the Thelia range, such as the 23 (post-CE), 623, and AS 23 (post-CE), among others. It is recommended to replace it when these symptoms are detected to restore the normal operation of the boiler.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference 05712700
PCB with reference 05712700. Four confirmed compatibilities: 23 (post-CE) and 623.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval 23 (post-CE) | Thelia | Contrasted |
| Saunier Duval 623 | Thelia | Contrasted |
| Saunier Duval 623 CE | Thelia | Contrasted |
| Saunier Duval AS 23 (post-CE) | Thelia | 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 ref. 05712700 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 05712700. 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 05712700 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 does not ignite and there is no reaction on the control panel.
Cause: A fault in the control circuit of the PCB prevents the ignition from starting.
Measure if 230V power is reaching the input of the PCB before replacing it.
- 02
The ignition fails intermittently; sometimes it starts and sometimes it doesn't.
Cause: A component of the PCB that degrades with heat can cause irregular ignition faults.
Observe if the fault occurs more when cold or after several hours of operation, this helps to determine if it is the PCB.
- 03
The boiler turns off by itself without showing any clear fault code.
Cause: A fault in the microcontroller of the PCB can cut off the supply without generating a warning.
Check the fuse on the PCB; if it is blown, the problem may be an external overload and not the board.
- 04
The panel controls do nothing, adjusting the temperature has no effect.
Cause: The PCB does not process user commands due to a fault in the control circuit.
Cut the main power for one minute and turn it back on; a microprocessor hang can be resolved this way and does not require changing the PCB.
Fault codes from Saunier Duval that this spare part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| F.63 | EEPROM fault. | The EEPROM memory of the PCB is corrupted or unreadable; the self-diagnosis locks the equipment. Verify by measuring the power supplies of the PCB and, if the peripherals are correct, confirm by reprogramming/initializing or replacing the PCB. |
| F.64 | Fault in the electronics / NTC. | The analogue-to-digital converter or the measurement stage of the PCB misinterprets the NTCs (incoherent readings). Verify the actual resistances of the NTC at the board connector and the continuity of the harness; if they are correct and the fault persists, the PCB is faulty. |
| F.70 | Invalid product code (DSN). | After replacing the display and/or PCB, the DSN has not been recoded or there are missing/errors in the coding resistor; the board goes into lockout. Check the appliance code in the service menu and recode (d.93) or install the correct resistor/code. |
| F.61 | Gas valve control/activation fault. | The PCB driver does not deliver the appropriate signal/voltage to the gas valve (or detects it as short-circuited). Check the continuity of the harness and the command voltage/waveform at the valve terminals during the ignition attempt; if the valve and wiring are fine and there is no correct command, the cause is the PCB. |
| F.28 | Start-up fault: ignition failed. | If the ignition/control stage of the PCB fails (does not excite the spark transformer or does not switch the valve), the burner does not start and F.28 appears. Check the spark and control voltage to the transformer/valve; if gas, electrodes, and harnesses are OK and there is no excitation from the PCB, the cause is the PCB. |
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 05712700 PCB.
- Catalogue reference
- 05712700
- Brand
- Saunier Duval
- Type of part
- PCBs (control boards)
- Units in stock
- 4 units
- 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.
- PCB code
- 8/050149
- Fuse
- 80 mA T
- Voltage
- 230 V
- Material classification
- PCL-13 / 94V-0
- Integrated circuit IC7
- HEF4541BP KSI C9423PS Hnn0001.2
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Saunier Duval 23 Manual (post-CE) (PDF)Document © Saunier Duval, provided as a technical reference.
Frequently asked questions about the PCB 05712700
What code should I check on the PCB of the Saunier Duval Combitek F 23?
Does this PCB work for the Saunier Duval Thelia 23?
What fuse does the Combitek F 23 PCB use and what voltage does it operate at?
When should this PCB be replaced in a Saunier Duval Thelia?
Spare parts related to Saunier Duval Thelia
