12-02-2023 06:58 AM
My A/C system lacks the blue wire for 'C,' so I purchased a transformer to connect to 'C' and 'RH.' Despite the transformer supplying 24v, the A/C refuses to start. The previous wiring configuration includes the yellow wire at 'Y1,' the green wire at 'G,' the white wire at 'W1,' and the red wire at 'RH.' I linked the two white wires from the transformer to 'C' and 'RH,' subsequently disconnecting the red wire from 'RH.' The Nest is charging and recognizing the wires, yet the A/C remains unresponsive.
Would you please let me know what could be the issue?
12-07-2023 09:35 AM
Hi ddennerr,
Uh-oh! I'm sorry to hear that your A/C system is not starting despite connecting a transformer to the C and RH terminals on the Nest Thermostat. To install a transformer with your HVAC system, ensure it matches the specific requirements of your A/C system. Double-check the wiring connections between the transformer and the Nest Thermostat, ensuring they are secure and free from loose or damaged wires. Install the transformer and a reliable power source, ensuring it provides the expected 24V output. Test the transformer's output voltage with a multimeter. Check your HVAC system for blown fuses or tripped circuit breakers, replace them if necessary, and test the system again. Some HVAC systems may require additional components or modifications to work with the Nest Thermostat and the transformer.
Let us know if that helps.
Best,
Zoe