Flexible Silicone Tube Pressure Switch Chaffoteaux Thema F 25 E - Ref. 0020039173
When you turn on the heating, the flexible silicone tube of the Chaffoteaux Thema F 25 E pressure switch ensures that the air or water pressure is maintained at the appropriate levels for the boiler to operate. If this part fails, you will notice that the boiler does not start or gets locked, even though the actual pressure may be correct, potentially displaying fault codes such as F2 or F3. This tube is compatible with several boiler models, such as the Thema F 25 E, among others from the Isotwin, Semia, and Themaclassic ranges. It is recommended to replace it when you observe these symptoms to avoid operational issues.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference 0020039173
Pressure switch with reference 0020039173. Eight confirmed compatibilities: F 25 E H-MOD and F 30 E H-MOD.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval F 25 E H-MOD | ISOTWIN | Contrasted |
| Saunier Duval F 30 E H-MOD | ISOTWIN | Contrasted |
| Saunier Duval F 24 | SEMIA | Contrasted |
| Saunier Duval F 25 E | THEMA | Contrasted |
| Saunier Duval F 24 E | THEMACLASSIC | Contrasted |
| Saunier Duval F 25 E | THEMACLASSIC | Contrasted |
| Saunier Duval F 25 E | THEMAPLUS | Contrasted |
| Saunier Duval F 25 E H-MOD | THEMAPLUS | 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. 0020039173 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 0020039173. 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 pressure switch 0020039173 resolves.
The pressure switch controls the air or water pressure to authorize operation. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The boiler ignites, makes an attempt, and shuts off after a few seconds, indicating a pressure switch or flue gas evacuation fault.
Cause: If the tube carrying the pressure signal to the pressure switch is broken, punctured, or disconnected, the pressure switch will not properly detect the vacuum, and the control unit will cut off the gas for safety reasons.
Visually check that the pipe is properly fitted at both ends and has no cracks or perforations before changing anything.
- 02
The boiler locks out as soon as the flue fan starts, even before attempting to ignite the flame.
Cause: A blocked or collapsed tube prevents the pressure switch from receiving the correct air pressure, so it never gives the command to continue the sequence.
With the boiler turned off, remove the tube and gently blow through it to ensure it is not blocked or crushed at any point.
- 03
The fault only appears with strong wind or when the external terminal is dirty, and other times the boiler works fine.
Cause: A poorly secured pipe or one with a small leak can result in unstable pressure readings, causing intermittent lockouts.
Check that the clamps or fittings of the pipe hold well and that no air is whistling from any point with the boiler running.
- 04
When opening the boiler, the pipe appears bent, crushed by another component, or with chafing marks.
Cause: A tube like this does not transmit pressure well to the pressure switch even if the latter is in perfect condition.
Reposition the tube away from parts that could pinch it and ensure that the path has no sharp bends before replacing it.
Fault codes from Saunier Duval that this spare part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| 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. |
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.
Datasheet for Saunier Duval Pressure Switch 0020039173
- Catalogue reference
- 0020039173
- Brand
- Saunier Duval
- Type of part
- Pressure switches
- 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 25 E H-MOD Manual (PDF)Document © Saunier Duval, provided as a technical reference.
Frequently asked questions about the pressure switch 0020039173
Is this flexible silicone tube the pressure switch for the ThemaClassic F 25 E?
Is this pipe suitable for my Semia F 24 boiler?
Spare parts related to Saunier Duval ISOTWIN
