Main PCB Saunier Duval Isofast F35E - PCB Code 105303
When you turn on the tap or start the heating, the Saunier Duval Isofast F35E Main PCB is responsible for controlling the ignition, the modulation of the burner, the pump, and the safety features of the boiler. If it fails, you will notice that the boiler does not start, locks out, or behaves erratically, and fault codes 13 or 20 may appear. This PCB is compatible with several models from the Isofast and Isomax ranges, such as the C 28 E and the F 35 E, among others. It should be replaced when it shows faults that affect the operation of the boiler.
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 ignite and there are no indicators or display active.
Cause: The PCB controls the power supply to the entire boiler; if it fails, current does not reach the other components.
Check that there is mains voltage reaching the PCB and that the input fuse is not blown before declaring it faulty.
- 02
The pump, the gas valve, or the fan do not start even though the boiler requests heat.
Cause: These elements are activated through the relays on the PCB; if one does not switch, the element does not receive power.
With the boiler in demand, measure with a multimeter if there is output voltage at the connector of the corresponding relay before changing the PCB.
- 03
An error code related to the main electronics is displayed.
Cause: The PCB detects an internal fault and displays it as a fault code.
Note the exact code and consult it in the manual: some codes point to sensors or external components, not to the PCB.
- 04
The boiler turns on intermittently or resets itself.
Cause: It may be due to the transformer that powers the control electronics, which experiences voltage drops in the secondary.
Check that the transformer wiring is properly connected and free of loose contacts before replacing the PCB.
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
- 2 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.
- Brand printed on PCB
- SAUNIER DUVAL
- Transformer
- Myrra (certifications VDE, UL, CE, EN 60950)
- Relays
- Zettler (x5)
- Fuse
- 125 mAT (timed)
- Main microcontroller
- S87C552-4A68
- Additional marking on PCB
- PHILIPS N00328 YL1548E 86A0
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.
Frequently asked questions about the PCB 05724800
What models are compatible with the Saunier Duval Isofast F35E Main PCB (code 105303)?
Does the reference RP SDI-F35E correspond to this PCB?
How many relays does the Main PCB with code 105303 have?
What fault codes are documented for this PCB?
Is this PCB compatible with the Isomax range?
Spare parts related to Saunier Duval Isofast
