I am installing a Honeywell Wi-Fi thermostat. I do not have a C wire, but there is an unused blue wire in the thermostat wiring, and also in the furnace wiring.
The videos I've watched say that I can use the unused blue wire as the C wire. That's no problem for the thermostat, but when I look at the furnace, there is already a wire in the C port. Can I put the unused blue wire in the C port, while still having the existing wire there (so, having both wires in the C port)?
I've included pictures of the thermostat and furnace.