Sn2
MAAX Spas High-Limit Sensor Fault

Display shows Sn2 or SN2; spa may shut down heater or show incorrect water temperature.

Advertisements

Safety Warning

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.

Advertisements

Possible Causes

Failed high-limit thermistor, Loose sensor connection, Damaged sensor wiring, Sensor not properly attached to heater tube

How to Fix / Troubleshooting

Safety: Turn off power at the breaker before working in the equipment bay.

  • Identify high-limit sensor: On MAAX control packs, the high-limit sensor is usually clamped or threaded to the heater tube separate from the main water temp sensor.
  • Check mounting: Ensure the sensor is firmly attached to the heater tube and has not pulled away or lost contact.
  • Inspect wiring: Follow the sensor cable back to the control board, checking for damage or loose plugs.
  • Clean contacts: If there is light corrosion on the connector, clean with electrical contact cleaner and reseat.
  • Reset power: Restore power and monitor. If Sn2 reappears, the sensor is likely out of calibration.
  • Replace sensor: Install a new MAAX-compatible high-limit sensor with the correct resistance curve. Do not bypass or jumper this safety device.
Advertisements

Repair Difficulty

Medium 3/5

Required Part

High-Limit Sensor
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements