How to Fix / Troubleshooting

Safety first: Turn off power before tightening terminals or inspecting wiring.

Inspect terminals: Tighten all line, neutral, and ground screws in the heater’s electrical compartment.
Check for corrosion: Clean any oxidized terminals with contact cleaner and re-secure.
Dedicated circuit: Ensure the heater is on a dedicated circuit not shared with pumps or other heavy loads.
Measure voltage: With a multimeter, check for voltage drops at the heater when it starts. Significant dips may require electrical service upgrades.
Board replacement: If supply is stable but flickering persists, the Thermeau control board’s power supply may be failing and should be replaced.

Heater display intermittently flickers or resets while running.

Possible Causes