I installed a General Aire 1042 for a customer in a 2000 sq' house. On a high velocity system. The system is wired properly cause the solenoid opens and water flows on a call for humidity. The customer has a hygrometer upstairs and registers 27% relative humidity. We can't get the RH up any higher is the problem. New house. New air handler. High Velocity system works well enough according to the customer. Humidifier is attached to the return with a 2"insulated bypass from the 8" supply on top of the air handler. Water supply was recently changed to the hot side hoping that would help with no success. The side of the humidifier is a 6" opening that I've installed a 6"cap and attached the 2" bypass as per the air handlers manufacturers instructions. Yes, the damper is open. Has anyone got any suggestions?