Heatline Flue Sensor D003201557

The Heatline flue sensor is a thermistor fitted to the flue path of Heatline Solaris and Soluxe gas boilers. It monitors flue temperature and feeds that reading back to the boiler's control board so the appliance can regulate combustion and shut down safely if flue conditions fall outside normal limits. This part carries the manufacturer code D003201557 and replaces code 3003201557.

• Boiler locks out or fails to fire, with a flue or temperature-related fault code logged
• Repeated shutdowns shortly after ignition as the control board reads an implausible flue temperature
• Erratic or intermittent heating and hot water operation that traces back to flue temperature sensing
• Sensor resistance readings outside the range expected for the flue temperature at the time of testing
• Visible damage, corrosion or a degraded connection at the sensor or its lead

• Confirm your boiler model against the fit list above, as the sensor is listed for Solaris and Soluxe appliances only
• Check the part number on the existing sensor or the manufacturer's parts list for your model
• Note that this part replaces manufacturer code 3003201557, so an older unit may carry that number
• Verify the fault code or resistance reading before ordering, as flue faults can also originate at the control board or wiring