Vaillant High Temperature Switch 0020210685

The Vaillant high temperature switch, part number 0020210685, is a safety control component used across the Vaillant VWF and Flexotherm VWF appliance families. It monitors temperature at its sensing point and interrupts the circuit when the set limit is exceeded, protecting the appliance from overheating. It is a serviceable part intended for replacement when the original switch fails or no longer operates within its threshold.

• The appliance locks out or shuts down during or shortly after a heating cycle.
• Overheat or high limit fault codes appear on the controls.
• The appliance requires repeated manual resets to run.
• Heating output cuts out intermittently with no other obvious cause.
• The switch shows continuity or resistance readings outside the expected range when tested.

• Confirm your appliance model matches one of the fit lines listed above.
• Check the part number on the existing switch before ordering.
• Verify the fault is traced to the high temperature switch rather than another safety device or sensor.
• Confirm the correct variant for your appliance, as fitment differs between models.