What does fault code F11 mean on Saunier Duval?

Connection fault with the user interface (display). The display PCB does not communicate with the main PCB (MMI/eBUS) or the harness between them is damaged; check power supply/5 V on the display and continuity of the wiring, and if applicable, test with a known good display.

What does fault code F18 mean on Saunier Duval?

User interface fault (display). Defect in the display PCB itself (keypad/screen) that prevents reading/sending signals; check connectors and power supply to the display, and if it persists, replace the display PCB.

What does the fault code F20 mean on Saunier Duval?

Software/coding incompatibility between PCBs. After replacing the display board or the main PCB without parameterizing, the product code/coding does not match (IRIS/eBUS); verify and readjust the product code according to the manual or install a compatible display.

RefurbishedSaunier Duval PCBs (control boards)

Saunier Duval Themafast NOx F 30 B 1 Display PCB Ref. 0020124928

Name: Saunier Duval Themafast NOX F 30 B 1 Display PCB Ref. 0020124928
Brand: Saunier Duval
SKU: DTNF30B1
Price: 65 EUR
Availability: InStock

65 €VAT includedIn stock · 1 unit

PCB (control board): refurbished spare part that controls the ignition, modulation, and safety features of the boiler. Useful if the boiler does not ignite, locks out, or the display is unresponsive. Reference 0020124928. Includes a one-year warranty and delivery within 2–4 working days in the EU.

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Delivery in 2–4 working days

1-year warranty

14-day return

Technical support

Key Data

Reference: 0020124928
Brand: Saunier Duval
Type of part: PCBs (control boards)
Available units: 1 unit in stock
Status: Refurbished
Warranty: 1 year
Shipping: 2–4 working days (EU)
Return: 14 days

Fault codes related to this part (not the entire boiler). They usually have more possible causes: first rule out electrodes, wiring/connections, and gas supply. Verified with ≥3 sources.

Code	What does it mean?	Cause and diagnosis (this part)
F11	Connection fault with the user interface (display).	The display PCB does not communicate with the main PCB (MMI/eBUS) or the harness between them is damaged; check power supply/5 V on the display and continuity of the wiring, and if applicable, test with a known good display.
F18	User interface fault (display).	Fault in the display PCB (keyboard/screen) that prevents reading/sending signals; check the connectors and power supply of the display and, if it persists, replace the display PCB.
F20	Software/coding incompatibility between PCBs.	After replacing the display PCB or the main PCB without parameterizing, the product code/coding does not match (IRIS/eBUS); verify and readjust the product code according to the manual or install a compatible display.

Saunier Duval Themafast NOx F 30 B 1 Display PCB Ref. 0020124928

Key Data

Spare Parts Related Boiler Themafast NOx F 30 B 1