Atlantic heat-pump water heater produces insufficient hot water in winter.

Safety: Turn off power before cleaning coils or filters.

• Verify the ambient temperature around the heater; if below the minimum specified by Atlantic, switch to boost/electric mode to supplement heating.
• Clean the air filter and evaporator coil fins with a soft brush or vacuum to restore airflow.
• Check the control panel mode; ensure it is not in ECO mode if higher output is needed.
• If demand has increased (more occupants), consider upgrading to a larger capacity Atlantic model or adding a second tank.