I recently replaced my old American Standard thermostat with Google Nest. Cooling works fine but Heat does not work and simply goes into an unending loop of 'delayed: will start in 2:30 secs'
I think the problem is in wiring, and especially blue wire.
My wiring diagram
New Nest Thermostat (If B wire in *OB, cool works and heat doesnt. If B wire is in C, nothing works)
Also the wire connector test looks like this. Google search said the lin is way too high, but not sure what it means.
Anyone has an idea what I am doing wrong? Thanks.
Update:
updated the wiring diagram with a bigger picture.
I bilieve i may have a heat pump outside the house. The outside installation looks like what google says is a heatpump.
Also,
zoomed out picture of furnace wiring: