Arrived to diagnose the issue of the condenser coming on with no call for cooling. Jumped the thermostat out and found that I had no 24v power. The transformer was bad. After replacing the transformer had voltage but did not get the zone valve to open. Found they had the two legs of the zone valve wired to R and W when it should have been wired to C and W. Webber replaced the zone valve just before my arrival and stated it was bad even though it was just wired incorrectly at the air handler. Once I got the zone valve wired I found the thermal sequencer was not turning fan on, replaced and tested the system. Once I put the thermostat back on the wall, only the outdoor unit would run in heat. The customer needs to order a new thermostat there is an issue internally with it. No other issues to report at this time. System is operational.