[HVAC] Ecobee3 + HRV wiring blew furnace fuse
However yesterday I turned on my HRV unit as I didn't test that to see if everything was working correctly. It was not…the HRV turned on, but the fan on the furnace did not. I checked, and my Ecobee was off. I took a look online and someone said to check if the furnace board fuse blew…and it did. There was a big black mark in the middle of the 3 amp fuse.
When I was first wiring the PEK from the Ecobee3, I did notice there was only one "G" wire to control the furnace fan which I found very odd.
The original HVAC company (Applewood) seems to have connected the fan wire running from the thermostat with the fan wire running from the HRV together and jumped it with another wire straight to the control board.
I called Ecobee support before installing and they said there should be no issues.
Well clearly something happened, because the fuse blew on the board. There are two things I think that may have caused the fuse the blow.
1) The HRV and PEK are both connected to the "R" terminal on the furnace control board. When I opened up to take a look, I noticed the HRV wire (in the "R" terminal) was a bit loose (seems like I didn't tighten it enough) so could that have short the fuse?
2) The inter-connected G wire isn't meant to be put into the PEK perhaps. I called Ecobee support again and they said the thermostat should only be connected to the PEK. I can then connect the PEK G wire and the HRV G wire separately into the G terminal. I don't know why there are wires interconnected with the thermostat (via a wire nut). Is this normal? I am still not even sure if the two wires connected together with the thermostat and HRV are truly the "G" wire. All I know is they are connected and there was only one G wire prior to installing the Ecobee.
Here is a diagram I tried to put together to make sense:
Side note: Is it okay to have 3 wires connected to the Comm/24V terminal? Currently I have the Ecobee3 PEK C-wire, my humidifier, and A/C. The PEK C-wire and humidifier are really close to each other in the terminal. This didn't cause the shortage as my humidifier is off and the Ecobee3 was working fine before, but just wanted to check for the winter.