Sn1 error, spa may not heat or may shut down

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Open or shorted water temperature sensor in Villeroy & Boch heater, Corroded sensor connector, Damaged sensor cable, Control board sensor input fault

Safety: Turn off power at the breaker.

Inspect sensor and wiring: Locate the primary water temperature sensor on the heater tube. Check that it is firmly seated and that its cable is intact.
Reseat connector: Unplug and replug the sensor connector on the Villeroy & Boch control board.
Check for damage: Look for cracks in the sensor body or cuts in the cable. Replace the sensor if damaged.

If a new sensor does not clear Sn1, the control board may be defective and should be replaced by a technician.

Hard 4/5

Water Temperature Sensor

Check Price on Amazon

We may earn a commission from links on this page.