Saunier Duval Isofast F 35 E1 Control Board Display Ref. 05721000
In Saunier Duval Isofast boilers, the Isofast F 35 E1 control panel is a PCB that manages the ignition, burner modulation, pump, and safety features of the unit. When it fails, you may notice that the boiler does not start, locks out, or exhibits erratic behavior. This part is compatible with models such as C 28 E, C 35 E, and F 28 E, among others. It is recommended to replace it if you experience these symptoms to restore the proper functioning of your boiler.
VAT included
Saunier Duval boilers compatible with reference 05721000
PCB with reference 05721000. 14 verified compatibilities: C 28 E and C 28 E1.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval C 28 E | Isofast | Contrasted |
| Saunier Duval C 28 E1 | Isofast | Contrasted |
| Saunier Duval C 28 E NOx | Isofast | Contrasted |
| Saunier Duval C 28 E1 NOx | Isofast | Contrasted |
| Saunier Duval C 35 E | Isofast | Contrasted |
| Saunier Duval C 35 E1 | Isofast | Contrasted |
| Saunier Duval F 28 E | Isofast | Contrasted |
| Saunier Duval F 28 E1 | Isofast | Contrasted |
| Saunier Duval F 35 E | Isofast | Contrasted |
| Saunier Duval F 35 E1 | Isofast | Contrasted |
| Saunier Duval C 28 E | Isomax | Contrasted |
| Saunier Duval C 28 E2 | Isomax | Contrasted |
| Saunier Duval F 28 E | Isomax | Contrasted |
| Saunier Duval F 28 E2 | 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. 05721000 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 05721000. 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 05721000 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 screen is off and there are no lights on the remote.
Cause: The display and control module is not receiving power or signal through the flat cable, even though the boiler is functioning.
Check that the 8-way flat cable is properly connected, with no bent or oxidized pins.
- 02
It does not respond when pressing buttons, nor does it change the temperature or turn on any lights.
Cause: The keyboard contacts may be worn or damp, preventing the transmission of the keystroke.
Check if the boiler is still heating with the current configuration; if it heats, the fault is in the control and not in the PCB.
- 03
The screen flickers, appears partially, or shows incomplete segments.
Cause: A poor connection in the flat cable or in the connections of the PCB causes the signal to be intermittent.
Disconnect and reconnect the flat cable with the boiler turned off, and check if the blinking changes when you slightly move the connector.
Fault codes from Saunier Duval that this spare part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| F12 | No signal from the user interface | Yes — it points to this display/interface module or its connection cable with the main PCB. |
| F18 | User interface fault | Yes — it corresponds to this display/control board module. |
| F13 | Main PCB fault | No — that code is for the MAIN PCB (a different part), not for this display. |
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 05721000 PCB.
- Catalogue reference
- 05721000
- 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
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 05721000
Does this display module fit an Isofast C35E1?
What connector does this module use to connect to the main PCB of the Isofast?
When should this display module be replaced in the Isofast F35 E1?
Does this module also work for an Isomax F28E?
Spare parts related to Saunier Duval Isofast
