Water Pressure Sensor Saunier Duval Isofast F 35 EA Ref. S5720500
The water pressure sensor Saunier Duval Isofast F 35 EA is a sensor that measures the pressure of the water circuit and sends this information to the control board. When this part fails, it can cause incorrect readings and lockouts in the boiler, generating the fault code F9: Water pressure detector failure. It is installed in boilers from the Isofast range, such as the model F 35 E, among others from the ThemaClassic series. It is advisable to replace it when pressure issues or related operational errors are detected.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference S5720500
Pressure sensor with reference S5720500. Six confirmed compatibilities: F 25 E and C 25 E.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval F 25 E | ThemaClassic | Contrasted |
| Saunier Duval C 25 E | ThemaClassic | Contrasted |
| Saunier Duval F 30 E | ThemaClassic | Contrasted |
| Saunier Duval C 24 E1 | ThemaClassic | Contrasted |
| Saunier Duval F 24 E1 | ThemaClassic | Contrasted |
| Saunier Duval F 35 E | 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. S5720500 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 S5720500. 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 sensor S5720500 resolves.
The pressure sensor measures the water pressure for the electronics. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The boiler displays a pressure on the screen that is very different from what the fill gauge indicates.
Cause: The sensor does not correctly convert the water pressure into an electrical signal for the PCB.
Compare both readings with the boiler cold and freshly bled before deciding that the sensor is faulty.
- 02
A pressure fault code appears repeatedly, even though when refilling the circuit, the reading initially rises well.
Cause: The sensor may give a correct reading at one moment and then deviate, which the PCB interprets as a pressure loss.
Monitor the reading on the screen for several minutes after filling, not just at the moment of filling.
- 03
The sensor you received looks different from the one you have installed, with the connector in a different color or the body made of another material.
Cause: There are variants of this sensor with different connectors or bodies depending on the batch or the original manufacturer, even though they perform the same function.
Compare the physical part with the one previously installed before fitting: same type of fitting, same type of connector, same thread diameter.
- 04
The boiler won't start, and the only message on the display is about pressure, even though the circuit is well filled and without leaks.
Cause: A sensor sending a value out of range causes the PCB to cut off the start as a safety measure.
Before replacing it, check with a mechanical manometer if you have one, and inspect the sensor connector in case it's just a bad contact.
Fault codes from Saunier Duval that this spare part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| F9 | Water pressure sensor fault. | The pressure transducer S5720500 delivers an absent/out-of-range signal or does not reach the PCB, the electronics interpret an abnormal pressure and lock with F9; verify by measuring the sensor signal and the harness/wiring and comparing with an external manometer. |
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 Saunier Duval pressure sensor S5720500
- Catalogue reference
- S5720500
- Brand
- Saunier Duval
- Type of part
- Pressure sensors
- Units in stock
- 6 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- Delivery time shown at checkout
- Return
- 14 days
- The body of this piece (orange connector, brass base) is different from other pieces in the same category reviewed in this batch (black plastic); it could be a different variant.
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 Manual (PDF)Document © Saunier Duval, provided as a technical reference.
Frequently asked questions about the pressure sensor S5720500
How do I distinguish this pressure sensor from the collector of the CPSDICF35E data sheet?
What does the marking 'LOT: 030613' mean on this pressure sensor?
Is this pressure sensor compatible with the Isofast F 35 E range?
Which models are compatible with this pressure switch?
What fault code is documented for this pressure sensor?
What is the reference for this pressure sensor?
Spare parts related to Saunier Duval ThemaClassic
