Pressure Sensor Saunier Duval Isofast C 35 E Ref. S5720500
The pressure sensor Saunier Duval Isofast C 35 E is a sensor that measures the water pressure in the boiler circuit and sends this information to the control board. When it fails, it can cause incorrect readings and lockouts due to false low pressure, which may manifest as fault code F9. This sensor is compatible with models from the ThemaClassic range such as the F 25 E and the C 25 E, as well as the Isofast F 35 E, among others. It is recommended to replace the part when these symptoms are detected or when accurate pressure readings are needed.
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 shows a filling or water pressure fault warning, but when checking the circuit, the pressure is correct.
Cause: The sensor does not transmit the actual pressure correctly, and the PCB interprets that the circuit is empty or poorly bled.
Before changing the part, check the pressure with the physical manometer of the boiler and compare it with the reading on the display.
- 02
The pressure indicator on the screen moves erratically or shows values that don't make sense.
Cause: The voltage signal sent by the sensor arrives distorted due to an internal fault or moisture in the connector.
Check that the connector of the sensor is dry and properly fitted; moisture in that area is a common cause of erratic readings.
- 03
The boiler does not ignite and the burner does not start, although the circuit is full.
Cause: Without a coherent pressure signal, the control board does not issue the ignition command for safety reasons.
Check that there is no air in the circuit and no visible leaks before assuming that the collector has failed.
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
- 4 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.
- Pressure range
- 0/4.5 bar
- Electrical output
- 1/4 Vdc (literal transcription from the label; it might actually be a range of 1-4 Vdc, uncorrected reading)
- Power supply
- 5 Vdc
- Protection class
- T70 / Class III
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
What pressure range does the sensor of the Saunier Duval Isofast C 35 E measure?
What power supply does the collector Ref. S5720500 need?
Does this sensor work for the Saunier Duval Thema C 25 E?
How many models are compatible with the Saunier Duval Isofast C 35 E Ref. S5720500 collector?
What fault code is documented for this sensor?
Can I use the sensor Ref. S5720500 in the Saunier Duval Isofast F 35 E boiler?
Spare parts related to Saunier Duval ThemaClassic
