I have a two part question focused to get my Aprilaire 560 humidifier operating.
First, I've deduced that the solenoid valve is not getting power. During furnace operation (carrier heat pump and gas furnace backup), using a voltmeter, no power is measured at the humidistat (red-white wire) or directly at the humidifier water control solenoid (2 white wires) with the manual control knob set to max. [I have cleaned and restored the solenoid and have confirmed it will function using a small voltage supply and there is supply water at the valve inlet.] Why is there no power coming to the solenoid and what do I correct to resolve?
Second, I just installed a Honeywell th8321wf1001 wifi thermostat. I would like to migrate from the old Aprilaire manual humidistat to using the HW TH8321 humidity control features. Is this a matter of simply moving the red/white wires from the humidistat and connecting to the R and U1 terminals in the TH8321 T/S and wiring directly to the water solenoid (and eliminate the power wires from the furnace)?