What does fault code 12 mean in Saunier Duval?

Communication error between interface circuit/main. The auxiliary interface PCB does not send/receive the signal to the main PCB (communication fault). Check 5 V power supply to the display and continuity of the harness/connectors; if it persists, replace the interface PCB.

What does fault code 18 mean on Saunier Duval?

User interface fault. Electronic fault of the interface board itself (e.g., memory/EEPROM or display circuit). Check power supply and wiring; confirm by replacing with a compatible and tested interface.

What does fault code 20 mean in Saunier Duval?

Software interface incompatible with IRIS software. User interface not compatible or poorly coded in relation to the main PCB (typical after replacing the interface/PCB without adjusting the coding). Check version/coding and reprogram or install the correct interface PCB.

RefurbishedSaunier Duval PCBs (control boards)

Saunier Duval Auxiliary Interface PCB Isomax F35 H MOD Ref. 0020048285

Name: Saunier Duval Auxiliary Interface PCB Isomax F35 H MOD Ref. 0020048285
Brand: Saunier Duval
SKU: PLAXIF35H
Price: 90 EUR
Availability: InStock

90 €VAT includedIn stock · 2 units

PCB (control board): recambio reacondicionado que gobierna el encendido, la modulación y las seguridades de la caldera. Útil si la caldera no enciende, se bloquea o el cuadro no responde. Referencia 0020048285. Includes a one-year warranty. Delivery time and cost are shown at checkout for the destination country.

Consult via WhatsApp

Not sure if it's your part? Send us a photo of the screen printing via WhatsApp and we'll confirm compatibility before you purchase.

Delivery calculated by destination

1-year warranty

14-day return

Technical support

Key Data

Reference: 0020048285
Brand: Saunier Duval
Type of part: PCBs (control boards)
Available units: 2 units in stock
Status: Refurbished
Warranty: 1 year
Shipping: Delivery time shown at checkout
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)
12	Communication error between interface circuit and main circuit.	The auxiliary interface PCB does not send/receive the signal to the main PCB (communication fault). Check the 5 V power supply to the display and continuity of the harness/connectors; if the issue persists, replace the interface PCB.
18	User interface fault.	Electronic fault of the interface PCB itself (e.g., memory/EEPROM or display circuit). Check power supply and wiring; confirm by replacing with a compatible and tested interface.
20	Software interface incompatible with IRIS software.	User interface not compatible or incorrectly coded with respect to the main PCB (typical after replacing the interface/PCB without adjusting the coding). Check version/coding and reprogram or install the correct interface PCB.

Saunier Duval Auxiliary Interface PCB Isomax F35 H MOD Ref. 0020048285

Key Data

Related Spare Parts Auxiliary Boiler Isomax F35 H MOD