Lay-Z-Spa displays E02 and stops heating; pump may still run but heater will not engage.

Safety first: Disconnect power at the mains and RCD plug before inspecting the pump/heater unit. Do not open the control housing while plugged in.

• 1. Power cycle the spa: Unplug the spa for at least 10 minutes to allow the control board to fully discharge. Plug back in, reset the RCD, and try to start the heater again. Temporary glitches can sometimes trigger E02.
• 2. Check water temperature: Compare the displayed temperature to an external pool thermometer. If the reading is wildly inaccurate (e.g., shows 0°C or 40°C when water is clearly different), the NTC sensor is likely faulty.
• 3. Inspect for scale and debris: With power disconnected, remove the pump from the liner and inspect the metal or plastic sensor pocket inside the water path (usually near the heater). Heavy limescale can insulate the sensor. Descale gently with white vinegar and a soft brush, then rinse thoroughly.
• 4. Check external wiring (if accessible): On some models, the temperature sensor cable is visible entering the control housing. Ensure it is not pinched, cut, or chewed. Do not open sealed housings unless you are qualified.
• If E02 remains: The NTC temperature sensor or the control PCB input circuit is likely defective. Replacement of the temperature sensor probe or the entire pump/heater unit is usually required. Contact Lay‑Z‑Spa support or a spa technician.