Indicator for Whole-House Humidifier

thingiverse

My whole-house humidifier is set to turn on when the furnace turns on (there's no separate humidity controller unit). I only want the humidifier to work in the winter so I wanted to add a switch inline with the control wiring so that I didn't have to manually connect and disconnect it each season. While I was at it, I added an LED to show when power is going to the Solenoid for the Water Valve. This 'thing' is just the case I designed to hold the switch and LED. I taped the case to the side of the humidifier with double sided tape. Polarity of the LED and Solenoid does not matter since the normal HVAC voltage is AC, 24vac. There's a wiring diagram in the photos. The resistor for the LED is 220k ohms. That's what I used and it works. The LED is 5mm in diameter. The slide switch is 0.750 inches between mounting screws. I didn't use supports and you can see the bridging nightmare caused by the bottom of the top panel when viewing the inside of the case. By the time it got to the top of the top layer, everything was pretty good.