I have a Aprilaire 600 humidifier attached to my WF 7 Geothermal HVAC. The themostat (TPCC32U01) is set to 45% humidity (the house will reach 40%). I have recently noticed that the humidifier will turn on (i.e. water flows) in the morning and brings the humidity up but when I return from work the HVAC is producing heat but the humidity is only 34-36% and the water is no longer flowing. Is it normal that the humidifier runs only part of the day or does the WF 7 have a time out for how long the humidifier runs in a given period? Thanks!