What does the fault code F2 mean on Saunier Duval?

Air shortage safety (Themaclassic F) If the silicone tube of the extractor pressure switch (0020039173) is blocked, cracked, or disconnected, the pressure switch does not close; the electronics interpret a lack of draft/air and trigger F2. Visually inspect the hose and Venturi connections, and check that the pressure switch activates by applying a vacuum.

What does fault code F3 mean on Saunier Duval?

Safety lack of draft The same pressure/draft defect due to a poorly placed, dirty, or broken pressure switch hose can recur and, after several attempts, lock in F3. Check the condition of tube 0020039173 and ensure the pressure switch closes with depression; check for blockages in inlets and ducts.

RefurbishedSaunier Duval Pressure switches

Flexible Silicone Tube Pressure Switch Extractor Saunier Duval ThemaClassic F 25 E Ref. 0020039173

Name: Flexible Silicone Tube Pressure Switch Extractor Saunier Duval ThemaClassic F 25 E Ref. 0020039173
Brand: Saunier Duval
SKU: CFLXF25E
Price: 5 EUR
Availability: InStock

5 €VAT includedIn stock · 5 units

Pressure switch: refurbished spare part that controls air or water pressure to authorize operation. Useful if the boiler does not start or shows a draft error. Reference 0020039173. 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: 0020039173
Brand: Saunier Duval
Type of part: Pressure switches
Available units: 5 units 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)
F2	Air shortage safety (Themaclassic F)	If the silicone tube of the extractor's pressure switch (0020039173) is blocked, cracked, or disconnected, the pressure switch does not close; the electronics interpret a lack of draft/air and trigger F2. Visually inspect the hose and Venturi connections, and check that the pressure switch activates by applying a vacuum.
F3	Safety lack of draft	The same pressure/draught defect due to a poorly placed, dirty, or broken pressure switch hose can recur and, after several attempts, lock in F3. Check the condition of tube 0020039173 and ensure the pressure switch closes with depression; inspect for any blockage in inlets and ducts.

Flexible Silicone Tube Pressure Switch Extractor Saunier Duval ThemaClassic F 25 E Ref. 0020039173

Key Data

Spare Parts Related Boiler ThemaClassic F 25 E