Air Pressure Switch Saunier Duval Isomax C28 E2 Ref. S5744000
The air pressure switch Saunier Duval Isomax C28 E2 is a component that controls the air pressure in the boiler, allowing it to operate properly. If it fails, the boiler may not start or may lock out, even if the actual pressure is correct, which can generate fault code 02: Flow/air draft failure. This pressure switch is compatible with models from the Isofast range, such as the Isofast F 28 E and the Isofast F 28 E1, among others. It is recommended to replace it when these symptoms or fault codes occur.
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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 burner does not ignite: the extractor starts, you can hear the attempt, and the boiler shuts down immediately.
Cause: The control unit waits for the signal from the air pressure switch before allowing the gas to flow; if it does not arrive, it cuts off the cycle for safety.
With the cover open and the extractor running, check if the pressure switch clicks when closing the contact.
- 02
The boiler locks out with a warning related to air or flue and needs to be reset to retry.
Cause: This message appears when the air pressure switch does not confirm the extraction to the control board.
Before replacing it, clean the flue gas outlet terminal: a partial obstruction also prevents reaching the switching pressure.
- 03
The fault comes and goes: sometimes it ignites on the first try and other times it locks out several times in a row.
Cause: A pressure switch with a fatigued diaphragm switches irregularly in response to small pressure variations.
Check that the connection pipes are not loose or have accumulated condensation inside, a common cause of intermittent faults.
- 04
The extractor has been changed and the ignition fault is still appearing.
Cause: If the extractor is working well and the pressure switch does not close the contact, the faulty part is the pressure switch itself.
Check the electrical continuity of the pressure switch with a multimeter before purchasing it, to rule out a wiring issue.
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.
- Switching pressure
- 54/46 Pa
- Electrical contacts
- 1(0.5) A / 250 V~
- Factory code (label)
- 605.99523
- Manufacturer's internal code
- 4000115830
- Batch code
- YV6C1C
- Manufacturing date
- 28/02
- This part is identical, by factory code and internal code, to the one sold for the Isofast F28 E2 (SKU PIF28E2); only the batch and manufacturing date differ.
Frequently asked questions about the pressure switch S5744000
Is this pressure switch Ref. S5744000 the one used in the Saunier Duval Isomax C28 E2?
Which models are compatible with the pressure switch Ref. S5744000?
What switching pressure does the pressure switch of the Isomax C28 E2 have?
What fault code is documented for this pressure switch?
What is the reference of the air pressure switch compatible with the Saunier Duval Isomax C28 E2?
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