Thermostat overshoots set temperature by several degrees before turning system off.

Safety first: No internal electrical work is required.

• Step 1 – Check location: Ensure the thermostat is on an interior wall away from direct sunlight, radiators, or supply vents. Relocate if necessary.
• Step 2 – Adjust control parameters: In the installer menu, adjust cycle rate, hysteresis, or proportional band settings according to Atlantic’s recommendations for your system type (radiators, underfloor, forced air).
• Step 3 – Enable floor sensor (if available): For underfloor heating, use a floor sensor and set the thermostat to combined air+floor control to reduce overshoot.
• Step 4 – Verify system type: Confirm that the thermostat is set to the correct system type (e.g. Electric UFH vs Water UFH), as this affects control algorithms.