If your single room heat recovery system is not functioning correctly, start by checking the filters and regenerator. Ensure they are clean, as clogged filters can significantly reduce efficiency.
Next, inspect the external vents to make sure they are not blocked by debris or obstructions, which could impede airflow. If these basic troubleshooting steps do not resolve the issue, consult the user manual for specific guidance related to your model. If problems persist, it's advisable to contact a professional technician or the manufacturer's customer service.