Pressure Sensor Isofast 21 Condens F30-B - Code 0020016532
The Isofast 21 Condens F30-B pressure sensor is a device that measures the water circuit pressure in your boiler. Its function is to send the reading to the control board to ensure proper operation. When it fails, you may notice incorrect readings and system lockouts, and the fault code F9: Water pressure detector failure may also be displayed. This sensor is compatible with boilers from the ThemaClassic and Isofast ranges, including models such as F 25 E, C 25 E, and F 35 E, among others. It should be replaced when you experience pressure issues or reading errors.
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 starts normally but stops in a pressure lock for no apparent reason.
Cause: The sensor sends intermittent signals that make the PCB believe there is a pressure drop that does not exist.
Note if the blockage occurs at the same time every time; if so, check the wiring of the sensor before replacing it.
- 02
The display shows a low pressure fault code even though the circuit is full and the pressure gauge confirms it.
Cause: The faulty sensor does not correctly inform the PCB about the actual pressure, causing a safety lockout.
Check with a physical manometer that the pressure is between 1 and 1.5 bar before replacing the sensor.
- 03
The boiler takes time to recognize that there is sufficient pressure after refilling the circuit.
Cause: A slow or damaged sensor delays the transmission of the correct signal to the control board.
Wait a few minutes after filling and bleeding; if the warning does not disappear, the problem is with the sensor.
- 04
The pressure value on the display fluctuates between different figures without intervention.
Cause: This indicates a sensor with noisy signals or a loose connector, which sends erratic readings.
Check that the connector is properly fitted and dry; gently move it while the boiler is on to see if the value stabilizes.
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
- 1 unit
- 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.
- Part code (label)
- 0020016532
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
Is this pressure switch suitable for an Isofast 21 Condens F30-B?
When should this sensor be replaced in an Isofast F35E?
Is the same part for the Isofast C28E1 and the Isofast C28E?
What fault code is documented for this pressure sensor?
How many models are compatible with this pressure switch?
What is the reference for this pressure sensor?
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