Baxi 720788201 Potterton & Main Hall Effect Sensor

The Baxi 720788201 is a Hall sensor supplied by Baxi for use in its heating appliances. It sits within the thermostats, thermistors and sensors group of spares and provides a feedback signal that the appliance's control electronics use to monitor movement or position within the unit. Fitting the correct sensor keeps the appliance running to its designed parameters rather than on a default or fault condition.

• The appliance locks out or shuts down shortly after starting, with the fault returning once reset.
• Fan or motor speed is reported incorrectly, or the control board cannot confirm that the component it monitors is turning.
• Intermittent operation that clears and returns without any other change to the appliance.
• A stored fault code pointing to a sensor or feedback circuit on the appliance display or diagnostic readout.
• Erratic behaviour that follows the sensor when it is swapped to another circuit during fault finding.

• Confirm the part number on the appliance data badge or in the manufacturer's literature matches 720788201.
• Note the model and GC number of the appliance so the correct variant is identified.
• Inspect any seal, gasket or retaining clip removed during access and replace it if it is compressed or damaged.