My A/C doesn't come on when I set the temperature on the Braeburn thermostat very low. Also, the recirculation fan doesn't come on when I set the thermostats fan setting to 'on', as though the indoor unit is not receiving any signal from the thermostat for either cooling or recirculation.
The setup:
- The AC worked at the end of the summer when we stopped using it.
- During the cooler months last year I was crawling around the attic doing work up there (I'm fairly fastidious and careful and I didn't bump anything that I'm aware of).
- I recently had new siding put on my house and the workers let the junction unit next to the outside condenser dangle while they installed the new siding
- I checked everything after the siding work was done (outside lights, AC, etc) and found the AC unit didn't come on
- I've measured 250V on the condenser side of the large fuse in the junction box that was left dangling. So, I don't think the workers did anything but am mentioning it here in case I've overlooked something.
- I've gone up to the attic where the indoor/fan unit is located and noted the wire connectors between like colored wires (red, yellow, green) are still there and weren't accidentally disconnected. See pictures below.
- Like colored wires between indoor fan unit and outdoor condenser are still firmly connected as well (red, yellow, brown).
- I've taken pictures of the wiring diagram on the side of the fan unit in the attic which shows RD, BR, GR/BK, WH/BK, WH/BL, YL going to thermostat (optionally, WH/BK and WH/BL tied together. So 5 or 6 wires to thermostat (this is only AC not heat if that matters). See pictures below.
- I've gone to the thermostat, disconnected the face unit from the wall and measured 27-27.5 volts White and all the other wires (Red, Yellow, Green). The thermostat is a Braeburn. See picture below.
While in the attic I stuck the voltmeter probes into some of the twist-on connectors but didn't measure anything. Before proceeding to take anything apart, what voltage should be across these wires going into the unit:
- Red (jumpered to another red running towards condensing unit)
- Yellow (also jumpered)
- Green (not jumpered)
Does anyone have any other advice on what to check?
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