Vaillant Temperature Sensitive Element 253517

The Vaillant 253517 is a temperature sensitive element used in Vaillant VK and VKS 1 E series appliances. It forms part of the appliance's temperature sensing circuit, allowing the control system to respond to changes in temperature during operation. It is supplied as a single component for replacement where the existing element is no longer reading or responding correctly.

• Temperature control becomes erratic or the appliance fails to hold a steady setpoint
• The appliance cycles or short-cycles more than expected during normal operation
• Overheat or temperature-related lockouts occur without an obvious cause elsewhere in the system
• Domestic hot water or heating flow temperature fluctuates noticeably between draws or cycles
• The element shows visible damage, corrosion or a disturbed connection at its mounting point

• Confirm the appliance model against the manufacturer's parts list before ordering
• Check the existing element and its connections to confirm the fault lies with the part rather than the wiring or control board
• Have the part fitted by a competent heating engineer where the appliance requires work inside the combustion or control circuit
• Verify the part number 253517 matches the number shown on the component being replaced