Saunier Duval Isofast/Isomax 28-35 Display-Control Module Ref. 05721000
Module of which only the rear plastic casing is visible in the available photo, with no visible connection cable or label, and no legible text. The manufacturer of the component is not specified, nor any technical data. It is compatible with the Isofast C, Isofast F, Isomax C, and Isomax F family according to the model list. It is replaced when the element it represents fails, even if not precisely identified.
Spare parts related to Saunier Duval Isofast
Saunier Duval boilers compatible with reference 05721000
PCB with reference 05721000. 14 confirmed compatibilities with two independent sources: C 28 E and C 28 E1. Verify the printed reference on your part before purchasing.
Compatibility confirmed
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval C 28 E | Isofast | Confirmed · 2 sources |
| Saunier Duval C 28 E1 | Isofast | Confirmed · 2 sources |
| Saunier Duval C 28 E NOx | Isofast | Confirmed · 2 sources |
| Saunier Duval C 28 E1 NOx | Isofast | Confirmed · 2 sources |
| Saunier Duval C 35 E | Isofast | Confirmed · 2 sources |
| Saunier Duval C 35 E1 | Isofast | Confirmed · 2 sources |
| Saunier Duval F 28 E | Isofast | Confirmed · 2 sources |
| Saunier Duval F 28 E1 | Isofast | Confirmed · 2 sources |
| Saunier Duval F 35 E | Isofast | Confirmed · 2 sources |
| Saunier Duval F 35 E1 | Isofast | Confirmed · 2 sources |
| Saunier Duval C 28 E | Isomax | Confirmed · 2 sources |
| Saunier Duval C 28 E2 | Isomax | Confirmed · 2 sources |
| Saunier Duval F 28 E | Isomax | Confirmed · 2 sources |
| Saunier Duval F 28 E2 | Isomax | Confirmed · 2 sources |
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.
- Locate the reference printed on the body of the PCB you have installed: it should indicate 05721000.
- Check your boiler model on the nameplate and look for it in the list of compatible models on this page.
- Compare the connections and the body with the original part before installing.
- If you have any doubts, send us a photo of the screen printing via WhatsApp and we'll confirm it for you before you purchase.
Symptoms and faults resolved by PCB 05721000
The PCB controls the ignition, modulation, and safety features of the boiler. These are the typical symptoms and what to do:
The boiler doesn't light up any indicator, it's completely dead.
Cause: The module is not delivering voltage to the rest of the circuits due to a fault in its power supply stage.
Check that 230V is reaching the boiler and that the main fuse has not tripped before considering the module as faulty.
A fault code appears on the display that does not disappear after resetting.
Cause: The module locks the equipment upon detecting an unresolved safety condition.
Check which component that code indicates in the model's manual before replacing the entire module.
The boiler cycles on and off without a heat demand.
Cause: An output from the module intermittently gives incorrect commands.
Note if the pattern repeats consistently or is random: a fixed pattern points more towards an external component than the module.
The wall control has no communication with the boiler.
Cause: The communication stage of the module with the thermostat has stopped responding.
Check the bus wiring and, if possible, try another control before replacing the module.
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.
Saunier Duval PCB (control board) 05721000 datasheet
- OEM 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
- In the available photo, only the plastic rear casing is visible, without a connection cable or a readable label; it is not possible to accurately confirm which component it is.
- The current catalog describes it as a 'Display Module', but this function is not confirmed by the available photo or any source; verify that it matches your part before purchasing.
- The current catalog lists reference 05721000; it is not confirmed by label or external sources.
- The manufacturer of the component is not listed.