Talked to Hien about issues with the home. Hien said the home is unbalanced and there are areas that are uncomfortable. The second floor is overcooling and it appears all registers supply air no matter what zone is calling. His bills are high - in the $800-$900 a month range. Reviewed the system in the attic space and found the bypass damper was not properly secured. Secured damper. Noticed there are 2 zones in the home and the dampers appear left and right. Could not see ductwork as it was under cellulose insulation. Found unit wired to Y1 only at thermostats and equipment. This is a Bosch heat pump. Turned on 1 zone and then the other and found no matter which zone was calling, air was being supplied to both zones, it was slightly reduced to the zone not calling, but still excessive air was blowing. Dampers were indicating they were in the proper positions. There is no return air to first floor. Need to go back and check airflow settings and confirm ductwork is properly