Pressure Sensor Saunier Duval, Protherm, and Vaillant (Isofast, Isomax, Isotwin, Thema)

Saunier Duval boilers compatible with reference S5720500

Pressure sensor with reference S5720500. Six confirmed compatibilities: F 25 E and C 25 E.

Proven compatibility

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.

1. 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.
2. Check the full boiler model on its data plate and look for it in the model associations on this page.
3. Compare the connections and physical body with the original part before installation.
4. 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 shows a low pressure fault when starting the heating, although at rest the reading seems normal.

  Cause: The sensor can fail due to the pressure variation caused by the circuit startup.

  Compare the reading at rest and when starting; if the jump is excessive compared to a mechanical manometer, suspect the sensor.

• 02

  No pressure value is displayed on the screen, as if the sensor is not connected.

  Cause: The sensor is not sending a signal to the PCB, either due to an internal fault or a poor connection.

  Check the three-pin connector before purchasing the part: make sure it is properly seated, without corrosion or moisture.

• 03

  The boiler works but sometimes it locks for a few seconds due to pressure and then continues on its own.

  Cause: An unstable signal from a sensor can cause intermittent cuts that the PCB interprets as pressure drops.

  Note when it occurs (start, stop, temperature change) to see if it matches a thermal pattern of the sensor.

• 04

  Have you checked the pressure gauge and the filling valve, and is the pressure problem still the same?

  Cause: If the water circuit is fine and the fault persists, the sensor that translates that pressure into an electrical signal needs to be checked.

  First, rule out leaks and air in the circuit; only if everything is fine, the sensor becomes the main suspect.

Fault codes from Saunier Duval that this spare part resolves.

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

2 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.

Label code

...40656 (cut off by the frame; prefix not visible)

Batch/date fragment

4 / 01

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.