Saunier Duval Isomax F 28 E2 Air Pressure Switch Ref. 605.99523
Air pressure switch for Saunier Duval boilers from the Isofast, Isomax, Isotwin, Opalia, Opaliatherm, and Thema ranges. It controls the differential pressure of the flue gas extraction circuit and allows ignition only if it detects correct draft. It is factory set to 54/46 Pa (open/close) and supports up to 1(0.5) A at 250 V~. It is replaced when the boiler locks out due to a pressure switch fault or does not detect extraction.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference S5744000
Pressure switch with reference S5744000. Two confirmed compatibilities: Isofast F 28 E and Isofast F 28 E1.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval Isofast F 28 E | Isofast | Contrasted |
| Saunier Duval Isofast F 28 E1 | Isofast | 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. S5744000 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 S5744000. 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 S5744000 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 tries to ignite several times and then locks out.
Cause: If the pressure switch does not switch quickly, the control board locks for safety after several attempts.
Check that the fan is clean and working properly, as a slow extractor can delay the operation of the pressure switch.
- 02
The display shows a flue fault warning and the boiler is not functioning.
Cause: The pressure switch verifies that the gas evacuation is correct before igniting the burner.
Check that the flue pipe is clear, especially after storms or snowfall.
- 03
The boiler starts up well most days, but it fails when it's cold.
Cause: Humidity and cold can cause water to accumulate in the pressure switch tubes, affecting its reading.
Bleed the connection pipes and make sure there is no water accumulation before considering the part as faulty.
- 04
Another part has been replaced and the ignition problem persists.
Cause: If the problem is with the pressure switch, changing other components will not resolve the blockage.
Check the electrical connectors of the pressure switch: a loose or corroded wire can cause the same fault as a broken part.
Fault codes from Saunier Duval that this spare part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| 02 | Airflow/flue fault (flue safety). | The air pressure switch does not switch when the fan starts (damaged diaphragm/contacts, obstructed intake tubes, or poor connection), so the PCB detects a lack of pressure drop and triggers the air fault; verify by measuring the continuity of the pressure switch (Pr terminals) with a multimeter during startup, and check the pressure and exhaust tubing. |
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 the Saunier Duval pressure switch S5744000
- Catalogue reference
- S5744000
- 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
Data read on the part and in the manufacturer's documentation
What we have not been able to verify does not appear here.
- Set (opening/closing)
- 54/46 Pa
- Electrical contact
- 1(0.5) A / 250 V~
- Part code
- 605.99523
- Internal code
- 4000115830
- Manufacturing date
- 14/03
- Production batch code
- VOGBED
Frequently asked questions about the pressure switch S5744000
Is the Saunier Duval Isomax F 28 E2 air pressure switch Ref. 605.99523 compatible with my boiler?
What is the correct reference for the pressure switch of the Isomax F 28 E2?
What pressure does the pressure switch of the Isomax F 28 E2 open and close at?
When should I replace the pressure switch of the Isomax F 28 E2?
What fault codes are documented for this pressure switch?
How many models are compatible with this pressure switch?
Spare parts related to Saunier Duval Isofast
