Saunier Duval Isofast/Isomax/Isotwin Boiler Extractor, Ref. 05723800
The Saunier Duval Isofast/Isomax/Isotwin boiler extractor, Ref. 05723800, is a flue fan that evacuates combustion gases and generates the necessary draft for the boiler to start. When this part fails, the boiler may not ignite or may lock out, presenting symptoms such as fault code 10: Fan failure or 02: Air flow safety (draft/suction defect). It is installed in boilers from the Isofast, Isomax, and Isotwin ranges, including models such as F28E, F28E1, F35E, and F24E, among others. It is advisable to replace the extractor when these operational issues are detected.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference 05723800
Extractor with reference 05723800. Six confirmed compatibilities: F28E and F28E1.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval F28E | Isofast | Contrasted |
| Saunier Duval F28E1 | Isofast | Contrasted |
| Saunier Duval F35E | Isofast | Contrasted |
| Saunier Duval F35E1 | Isofast | Contrasted |
| Saunier Duval F28E | Isomax | Contrasted |
| Saunier Duval F24E | Isotwin | 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. 05723800 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 05723800. 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 extractor 05723800 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 starts, but it stops and locks after a few seconds.
Cause: The extractor does not reach the necessary speed for the air pressure switch to confirm the draft; if it fails to do so, the control board cuts off the ignition.
Listen to see if the extractor reaches a stable speed or if it stops halfway: if it stops halfway, check the silicone tubes of the pressure switch, as they may cause the same symptom.
- 02
The fan makes excessive noise, like a high-pitched whistle or noticeable vibrations.
Cause: The wear of the bearings or the accumulated dirt on the blades disrupts the rotation of the rotor.
With the boiler off and unplugged, turn the rotor by hand: if you feel irregular resistance or metallic rubbing, wear is confirmed.
- 03
The boiler does not attempt to ignite and shows a fault with the fan directly.
Cause: If the motor does not start at all, it may be due to a burnt winding or a depleted start capacitor.
Check with a multimeter that the extractor is receiving power at its terminals when requesting ignition, before considering it faulty.
- 04
The fault occurs especially when starting cold, after several hours of being idle.
Cause: Dry bearings offer more resistance to cold starting than when they have been running for a while.
If the fault disappears when giving a small manual push to the rotor with the boiler off and cold, it is a clear indication of worn bearings.
Fault codes from Saunier Duval that this spare part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| 10 | Fan fault. | The extractor fan motor does not start or is not recognized by the PCB (open winding, blockage, or wiring). Check that it receives 230 V~ at terminals, that it spins freely, and continuity/insulation; if it does not start, replace the fan. |
| 02 | Air flow safety (draft/aspiration fault). | The extractor does not generate the required flow/depression and the air pressure switch does not switch; there may be a blockage in the fan or flue circuit. Verify that the fan receives voltage and rotates, and check the closure of the pressure switch with the fan running and without obstructions in the exhaust. |
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 05723800
- Catalogue reference
- 05723800
- Brand
- Saunier Duval
- Type of part
- Extractors
- Units in stock
- 3 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 Isofast F35E1 Manual (PDF)Document © Saunier Duval, provided as a technical reference.
Frequently asked questions about the extractor 05723800
Is this extractor suitable for the Saunier Duval Isofast F28 E1?
Is the same fan suitable for the Saunier Duval Isotwin F24 EA?
What symptoms indicate that the fan of the Isofast F35 E is failing?
Spare parts related to Saunier Duval Isofast
