
Saunier Duval Hermann Thema NOx F24 Flue Gas Extractor Fan Ref. H035003719
When the heating starts, the Saunier Duval Hermann Thema NOX F24 Smoke Extractor Fan Ref. H035003719 is responsible for evacuating the combustion gases, creating the necessary draft for the boiler's operation. If this part fails, you will notice that the boiler does not ignite or locks out due to flue gas evacuation issues, and you might see the fault codes F2, F33, or F.32. It is compatible with models such as Thema NOX F24, Thema F24 NOX, and Supermicra Ecoplus 24, among others. It should be replaced when a malfunction is detected or when the mentioned symptoms occur.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference H035003719
Extractor with reference H035003719. Five confirmed compatibilities: Thema NOX F24 and Thema F24 NOX.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval Thema NOx F24 | Thema NOX (Saunier Duval) | Contrasted |
| Saunier Duval Thema F24 NOx | Thema NOX (Saunier Duval) | Contrasted |
| Saunier Duval Supermicra Ecoplus 24 | Supermicra Ecoplus (Hermann) | Contrasted |
| Saunier Duval Supermicra Ecoplus 24KW | Supermicra Ecoplus (Hermann) | Contrasted |
| Saunier Duval Supermicra Ecoplus 24SE | Supermicra Ecoplus (Hermann) | 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 the reference H035003719 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 H035003719. If it is not visible, do not identify the part by 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 extractor H035003719 resolves.
The extractor evacuates the combustion gases with forced draft. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The boiler tries to ignite, the fan can be heard but it stops quickly and a lockout appears.
Cause: If the extractor does not rotate consistently, the pressure switch loses the signal and the control board cuts off the ignition.
Check if the extractor stops and starts on its own, or if the motor noise changes during the ignition attempt.
- 02
The extractor makes a metallic noise or vibrates when starting, louder than before.
Cause: A worn or dirty impeller strikes the casing while rotating.
With the boiler turned off, check if the extractor shaft turns smoothly or if it shows resistance and noise.
- 03
The extractor is spinning, but very slowly or making a different effort sound than usual.
Cause: Worn bearings or a seized shaft hinder the motor's rotation.
Check if the fan starts immediately or if it needs an audible push to reach speed.
- 04
The boiler has been working well for a while and suddenly it starts to lock out repeatedly due to a flue fault.
Cause: The wear of the extractor reduces the airflow until it no longer reaches the minimum required for the safety of the boiler.
Before changing the part, clean or check the flue duct and the exterior grille to rule out obstructions.
Fault codes from Saunier Duval that this spare part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| F2 | Airflow fault/air pressure switch (lack of draft). | If the extractor fan does not start or does not generate the minimum depression, the pressure switch does not close and the boiler locks with F2; check the power supply voltage to the fan and that the pressure switch closes during start-up (differential pressure measurement). |
| F33 | Air flow fault (after St33 attempts). | If the fan does not create sufficient depression or does not spin, the air pressure switch remains open and, after several ignition attempts (St33), F33 appears; check the fan's rotation/power supply and pressure in the pressure switch during startup. |
| F.32 | Fault: fan. | Direct fault of the fan (winding/capacitor/Hall sensor) or its wiring prevents the PCB from detecting the rotation; check power supply, continuity, free rotation, and tachometer signal of the fan. |
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.
Data sheet for the Saunier Duval extractor H035003719
- Catalogue reference
- H035003719
- Brand
- Saunier Duval
- Type of part
- Extractor fans
- Units in stock
- 6 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- Delivery time shown at checkout
- Return
- 14 days












