Saunier Duval Isofast/Isomax Display and Control Module Ref. 05721000
The Saunier Duval Isofast/Isomax display and control module is a PCB that manages the ignition, burner modulation, pump, and safety features of the boiler. When it malfunctions, the boiler may fail to start, lock out, or operate erratically, displaying possible fault codes such as F12, F18, or F13. This module is compatible with several models, including the C 28 E, C 28 E1, C 35 E, and F 28 E, among others. It is recommended to replace it when these operational issues are detected.
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Consult via WhatsAppSaunier 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 flickers or turns off by itself intermittently, especially if you touch or gently hit the control.
Cause: The module connects to the PCB via a flat cable and contacts that, due to vibration and heat, lose grip.
Check that the flat cable is properly inserted into its connector and without folds before assuming that the module is broken.
- 02
The buttons do not respond no matter how firmly you press them.
Cause: The contacts of the control unit degrade with use and the humidity in the boiler room, losing electrical continuity.
Gently clean the area around the control and reinsert it into its housing before replacing it.
- 03
The boiler is working (providing heating or hot water) but the control does not display anything or allow any adjustments.
Cause: In these models, the control is primarily the interface; the ignition control can still be managed by the main PCB even if the panel is blank.
Check that hot water is actually coming out or that the radiators are heating; if so, the problem is limited to the control and not the PCB.
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
- 1-2 business days
- 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
For which boiler models is the Saunier Duval Isofast/Isomax display and control module Ref. 05721000 compatible?
What fault codes are compatible with this module?
What is the reference for the display and control module of Saunier Duval?
Is this module compatible with boilers from other brands?
What fault symptoms may indicate the need to replace this module?
Spare parts related to Saunier Duval Isofast
