
PCB Saunier Duval Isofast C 35 E - Code SYMSI7.0 0310144400015
The Saunier Duval Isofast C 35 E PCB regulates the ignition, the modulation of the burner, the pump, and the safety features of the boiler. If it malfunctions, the boiler may not start, become locked, or operate erratically. This PCB is compatible with several models in the Isofast range, such as the C 28 E, C 28 E NOx, F 28 E, and F 35 E, among others. It is recommended to replace it when fault codes 13 or 20 appear.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference 05724800
PCB with reference 05724800. Eight confirmed compatibilities: C 28 E and C 28 E NOx.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval C 28 E | Isofast | Contrasted |
| Saunier Duval C 28 E NOx | Isofast | Contrasted |
| Saunier Duval F 28 E | Isofast | Contrasted |
| Saunier Duval C 35 E | Isofast | Contrasted |
| Saunier Duval F 35 E | Isofast | Contrasted |
| Saunier Duval C 24 E V | Isofast | Contrasted |
| Saunier Duval C 28 E | Isomax | Contrasted |
| Saunier Duval F 28 E | Isomax | 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. 05724800 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 05724800. 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 05724800 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 turn on and there is no sign of activity on the display or the LEDs.
Cause: The power supply stage of the PCB may have failed, leaving the rest of the electronics without power.
Check the input voltage to the PCB and the condition of the fuse before replacing it.
- 02
A fault code related to ignition or flame appears, and it doesn't reset.
Cause: The ignition circuit of the PCB is not sending or interpreting the flame signal correctly.
Check the ignition/ionization electrode and its wiring before assuming the fault is in the PCB.
- 03
The pump or the fan keeps running continuously, even though the boiler is not requesting heat.
Cause: One of the relays on the PCB has stuck and is not cutting power to the component.
Check if the corresponding relay clicks when starting and stopping the unit before replacing the PCB.
- 04
The boiler responds erratically to commands from the control or the programmer.
Cause: The communication circuit of the PCB with the peripherals fails intermittently.
Disconnect the controller or programmer and operate the boiler from the local panel to isolate the source of the fault.
Fault codes from Saunier Duval that this spare part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| 13 | Main printed circuit board fault. | The main PCB is faulty. Check auxiliary voltages (5/12 VDC) and connectors of the PCB; if the power supply and wiring/UI are correct and the board does not deliver voltages or shows damage/continuous reset, replace the PCB. |
| 20 | Communication fault/incompatible interface with the main PCB. | The main PCB is incompatible or there is a communication failure with the user interface (coding/DSN or e‑Bus). Verify product code and compatibility UI↔PCB; if the fault persists with the correct UI, 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 05724800 PCB.
- Catalogue reference
- 05724800
- Brand
- Saunier Duval
- Type of part
- PCBs (control boards)
- Units in stock
- 5 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
- SYMSI7.0 / 0310144400015
- PCB reverse code
- SYMSI7.0 125872-17 CA0-8745 FG
- relays
- OMRON G5Q-1A DC24V (x3), 5A 30VDC / 10A 250VAC~; refs. REL101H/REL102YC/REL104D; batches 31X6C3/19X6C2/1596C1
- Driver IC
- TOSHIBA ULN2803AG
- transformer
- 4744-E 0641
- Traceability marking
- 00200211 18 105-5896 / 0710 KWD 1ND5 S0000 (batch marking, not sales reference)
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Saunier Duval F 28 E Manual (PDF)Document © Saunier Duval, provided as a technical reference.












