Saunier Duval Isofast F 35 E PCB Ref. 05724800
The Saunier Duval Isofast F 35 E PCB is the heart that controls the ignition, the modulation of the burner, the pump, and the safety features of the boiler. If it has faults, the boiler may not start, become locked, or behave erratically, which can manifest through fault codes 13 or 20. It is compatible with various models in the Isofast range, including the C 28 E, F 28 E, and C 35 E, among others. It is recommended to replace it when these symptoms of malfunction are detected.
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 is no light or sound when pressing the start button.
Cause: The protection fuse of the PCB has blown due to a power surge or a downstream short circuit.
Check the fuse with a flashlight: if the filament is broken or the glass is darkened, make sure that the component that caused it to blow is not still damaged before replacing the PCB.
- 02
A click is heard on the PCB when starting, but the boiler does not ignite.
Cause: The output relay that activates the gas valve does not close the contact properly.
Check that the relay click sounds firm and that the gas inlet valve is open before replacing the PCB.
- 03
The boiler runs for a few minutes and then stops by itself with a fault code.
Cause: The PCB cuts off the supply when it detects an anomaly in its control sequence as a protective measure.
Note the code displayed and compare it with the manual before considering the PCB as the cause: many codes point to external sensors or pressure switches.
- 04
The display and remote control do not respond to any button presses, although the boiler seems to have power.
Cause: The transformer or the power supply stage of the PCB is not delivering the correct voltage to the rest of the circuit.
Measure if there is voltage at the output of the transformer on the PCB before assuming that the entire board is faulty.
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.
- Fuse
- 125 mAT (timed)
- Relay
- Finder 34.51, 24VDC, 8A 250VAC~
- Transformer
- Myrra, EN 60950, CE
- Micro switches
- SW1 and SW2, labeled "PONTET"
- The main chip text (type TQFP) still cannot be read reliably, even when enlarged.
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
Is this PCB 05724800 suitable for a Saunier Duval Isofast F 35 E?
Does the PCB 05724800 also work for an Isomax C 28 E?
What relay is mounted on the PCB 05724800?
What fuse does this PCB of the Isofast F 35 E have?
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