Saunier Duval Thelia 23 Multifunction PCB Ref. PCB.1390-A
If your boiler does not start, locks out, or exhibits erratic behavior, you may need the Saunier Duval Thelia 23 Multifunction PCB. This control board is responsible for managing the ignition, burner modulation, pump, and safety features of the boiler. Users may notice issues such as fault code F.28, which indicates a start-up failure, or F.64, which points to an electronic fault. It is compatible with several models in the Thelia range, including the 23 (post-CE) and the 623, among others. It is recommended to replace it when these faults or symptoms are detected.
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 seems to be on, but the pump or the fan does not start.
Cause: The relay on the PCB that controls that component does not close the contact even though the rest is functioning.
Measure with a tester if there is power at the connector of the pump or the fan when the boiler needs heating.
- 02
The wall thermostat does not affect the boiler, even when the temperature is changed.
Cause: The PCB does not receive or process the demand signal from the thermostat.
Check the wiring and the thermostat connection at the terminals of the PCB before replacing it.
- 03
The fuse of the PCB blows when connecting the boiler to the power supply.
Cause: The PCB detects a short circuit and protects the circuit by blowing the fuse.
Before installing a new fuse, check that there are no exposed wires or components like the pump or a valve in a short circuit.
- 04
The boiler works well for domestic hot water but not for heating, or vice versa.
Cause: The relay that separates both circuits on the PCB only fails in one of the operating modes.
Force each mode separately from the thermostat or the selector to determine if the fault is due to demand or the control board itself.
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
- 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.
- Voltage
- 230 V
- Fuse
- 125 mA T
- PCB code
- PCB.1390-A
- PCB manufacturing code
- 8/050155C
- Manufacturing date of the PCB
- 95/09/26
- Adhesive label
- 100132 G / 97-42 SFL
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
Is this board Ref. PCB.1390-A the same as the one in the Thelia AS 23 data sheet (PCB.1330-A)?
What fuse does the PCB of the Saunier Duval Thelia 23 use?
Is this PCB compatible with the Saunier Duval Thelia 23?
How many models are compatible with the PCB Ref. PCB.1390-A?
What fault codes are documented for this PCB?
Where can I find the reference for this PCB?
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