FAQ
There is suction in…
There is suction in the hole on the combination box installed in our home – what is the cause?
If you experience draft or suction in a hole on the combination box, this may indicate incorrect installation. Many people are unsure what is considered normal operation and what points to an error in the duct connections.
Answer:
If there is suction in the hole on the combination box, the most likely cause is that the box has not been installed correctly. For example, the ducts may be connected incorrectly, with supply air and extract air swapped. This must be checked and corrected by the installer to ensure proper operation of the ventilation system.