Heater appears to run normally but energy consumption is unusually high.

Safety first: No special electrical safety beyond normal precautions is required for this optimization.

• Use a pool cover: Fit and regularly use a thermal cover to reduce evaporation and heat loss.
• Optimize setpoint: Lower the thermostat to the minimum comfortable temperature.
• Schedule heating: Run the heater during off-peak times or warmer parts of the day if possible.
• Check insulation: Insulate exposed pipework near the Elecro heater to reduce losses.

These measures reduce run time and energy use without modifying the heater itself.