
Main PCB Saunier Duval Isofast F28E Ref. 05724800
The Saunier Duval Isofast range boilers use the Isofast F28E Main PCB, which is responsible for controlling functions such as ignition, burner modulation, the pump, and system safety features. If this part fails, the boiler may not start, become locked, or exhibit erratic behavior. Users may notice issues such as fault code 13, which indicates a failure in the main printed circuit, or fault code 20, which signals a communication defect. This model is compatible with various boilers, such as the C 28 E, F 28 E, and others from the Isofast and Isomax ranges. It is recommended to replace the PCB when these malfunction symptoms occur.
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 or respond to the controls, as if it were 'turned off inside'.
Cause: The microcontroller on the PCB controls the ignition; if it doesn't work, there is no ignition.
Check that power is reaching the PCB and that the fuse is not blown before replacing it.
- 02
The fault persists even though other components have been checked and are fine.
Cause: If the pressure switch, gas valve, and sensors are in good condition, the PCB is the one that coordinates the entire process.
Check the boiler's error history to confirm that it does not indicate a specific component before replacing the PCB.
- 03
The pump or the valve do not start even though the boiler seems to initiate the ignition cycle.
Cause: The relays on the PCB send the electrical signal to the pump, gas valve, and burner; if one fails, that element does not receive power even though the cycle continues.
Measure with a multimeter if voltage reaches the affected component at the moment it should be activated, before blaming 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
- 5 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- Delivery time shown at checkout
- 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 reference
- 05724800
- Microcontroller
- Philips N00328 YL1548E 86A0
- PCB code (factory)
- 105303 G / 9950 / EPiQ
- Relays
- Zettler AZ696-1A-24DE, 8A / 250VAC
- Fuse
- 125 mAT (timed)
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.












