Saunier Duval Display Module Control Board Isomax F28 E2 Ref. 05721000
The control PCB of the Saunier Duval Display Module Isomax F28 E2 manages 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. Users may notice issues such as the appearance of fault codes F12, F18, or F13. It is installed in boilers from the Isofast and Isomax ranges, including models like C 28 E, F 28 E, and C 28 E2, among others. A technician must confirm through diagnosis whether it needs to be replaced when these symptoms or errors occur.
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
The part reference, model, and equipment revision must be verified against the manufacturer's documentation.
- 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 that require diagnosis on the PCB 05721000
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 rear cover of the module does not close properly or has come loose from its clips.
Cause: The plastic tabs that hold the casing break over time and with temperature changes.
Check each clip separately with a flashlight; sometimes it is enough to reinforce just one.
- 02
The module vibrates or sounds like loose plastic when the boiler is running.
Cause: Without the casing properly fitted, the PCB and the internal connectors lose their support and vibrate with the pump and the fan.
With the boiler off, check if the module moves when pressed gently.
- 03
There is moisture near the module and, from time to time, the boiler fails or locks out for no apparent reason.
Cause: A cracked or poorly closed casing allows moisture to enter the electronics.
Check for cracks, burrs, or whitish areas in the plastic before assuming that the fault is with the internal electronics.
- 04
There is a missing piece of plastic or a visible crack on the back of the module.
Cause: A blow during handling or a previous disassembly may have damaged the casing.
Take a photo of the damaged area and compare it with the parts diagram before ordering the part, to confirm that it is this casing and not another part of the module.
Fault codes Saunier Duval that require diagnosis
| Code | Fault | Technical checks |
|---|---|---|
| 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
- Uniclima internal SKU
- MODXF28E
- Brand
- Saunier Duval
- Type of part
- PCBs (control boards)
- Units in stock
- 4 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 casing also fit an Isofast C 28 E?
Spare parts related to Saunier Duval Isofast
