Saunier Duval Isofast C 35 E PCB Ref. 105.304 E
The Saunier Duval Isofast C 35 E E PCB is the component that controls the ignition, burner modulation, pump, and safety features of the boiler. When it fails, the boiler may not start, become locked, or exhibit erratic behavior. It may display fault codes such as 13: Main printed circuit board fault or 20: Communication defect/incompatible interface with the main board. It is compatible with models from the Isofast range, such as the C 28 E, C 28 E NOx, and F 35 E, among others. It should be replaced upon detecting any of these symptoms or errors.
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 because it loses power.
Cause: The 125 mA fuse that protects the PCB has blown and cuts off power to the microcontroller.
Measure the fuse on the PCB with a multimeter before replacing it completely.
- 02
The pumps or valves fail intermittently while the rest of the boiler operates well.
Cause: The relays that control these components are on the PCB, and a worn relay can cause faults that appear to be from the actuator.
If the boiler's software allows it, manually activate the pump or the valve to check if the problem lies in the actuator.
- 03
Errors appear on the PCB or the boiler locks without a clear pattern.
Cause: The microcontroller that manages the ignition and regulation logic may fail intermittently.
Note the exact fault code and perform a reset 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
- 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.
- code printed on PCB
- 105.304 E (A100803687)
- main microcontroller
- NXP N00357 YL1548F 85DF 01EP
- transformer
- MYRRA (VDE, UL, CE, EN 60950)
- relays
- SCHRACK RY430024 (x4) and SCHRACK V23061-B1007-A301 (x1)
- fuse
- 125 mAT
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
Does this PCB work for a Saunier Duval Isofast F 35 E?
Does this PCB also work for an Isomax C 28 E?
What fault does replacing the PCB of the Saunier Duval Isofast/Isomax resolve?
What fuse is mounted on the PCB of the Isofast C 35 E?
Spare parts related to Saunier Duval Isofast
