Vaillant Flue Temperature Sensor 253511 Replacement Part

the vaillant flue sensor 253511 now use 1377548 monitors flue temperature so the boiler can run safely and shut down if abnormal heat is detected. because flue temperatures can rise quickly during operation, the sensor’s readings help the boiler control combustion and protect internal components.

if the sensor is faulty you may see flue sensor fault codes, intermittent lockouts, or heating/hot water cutting out as the boiler stops for safety. replacing it with the correct vaillant flue sensor 253511 is often the most reliable fix to restore accurate flue monitoring, improve stability, and reduce the risk of repeated shutdowns.

Compatibility :

• Thermocompact VC 180XT 1995-1996
• Thermocompact VC 240XT 1995-1996

Important fitting advice

We recommend that all parts are fitted by a fully qualified Gas Safe registered engineer. If you need help confirming the right part, contact us our team has 10+ years of boiler spares knowledge and friendly chat support to help you quickly.

Delivery

At Boiler Spares Hub, we dispatch orders within 1 working day (Monday-Friday). Orders placed outside working days will be dispatched on the next working day. For delivery options available for this product, please add it to your basket or check our delivery options page.

Returns

We accept 30-day returns. Returns must be in an unopened, sealed box. If we find the item has been used or installation was attempted, we may refuse the return.

Frequently Asked Questions (FAQs)

1. What does the Vaillant flue sensor 253511 do?
It measures flue temperature and feeds that information to the boiler controls, helping the boiler regulate combustion and shut down safely if temperatures go out of range.

2. What symptoms suggest the flue sensor is failing?
Typical signs are flue-temperature related fault codes, random lockouts, heating or hot water cutting out mid-run, or the boiler needing frequent resets.

3. Why does my Vaillant boiler show a flue sensor fault?
Common causes include the sensor drifting out of range, a loose/oxidised connector, damaged wiring, or conditions that make the boiler believe flue temperature is abnormal (like restricted airflow).

4. Can the flue sensor be cleaned instead of replaced?
Sometimes light soot/dust on the probe or a dirty connector can affect readings, but if faults keep returning, replacing with the correct Vaillant flue sensor 253511 is usually the most reliable fix.

5. Where is the flue sensor located?
It’s normally positioned in/near the flue path or combustion area so it can accurately sense flue temperature. Exact location depends on the boiler model.