HVAC Wiring Box

A mod of an existing box and some generic connector brackets to contain the wiring for our furnace & heat pump.  The original wiring left by the contractor was just a messy ball of twist-on connectors and it did not contain the humidifier valve connection either. This makes it much tidier.

This adds an LED panel that will take 3mm LEDs so that you can see the status of the furnace at a glance.  I put all the LEDs in series with a single small power diode to C and a 10K resistor to the appropriate line.  All hand wired on a prototype board.

I added a flag to each of the connector brackets to identify the connected wires. The same mount was used for all the connectors.

There is a lid with “HVAC” on it and one with just the original graphics.

For the added parts you will need half a dozen M3 screws and inserts

My next thought is to use a small controller under the LED panel to select the furnace when the electricity rate is high and the heat pump is selected.

Remember to turn the circuit breaker off before messing with the furnace wiring.

To print things I printed the connector mounts on side with support and the LED front panel was printed face down with supports.  I printed it all in PLA with PETG supports and it seemed to turn out OK.

Update: added an LED frame that would accommodate LEDs on a prototype board with 0.1 inch spacing.