It sounds like you've taken the appropriate steps to troubleshoot the issue with your Nest Thermostat and Heat Link. If you've followed the reset instructions and confirmed that the power to the wiring is good, but you're still not seeing any lights on the Heat Link, there might indeed be an issue with the Heat Link itself.
Before jumping to the conclusion that you need a new Heat Link, here are a few additional steps you can consider:
Check Wiring Connections: Double-check that all the wiring connections are secure and properly connected to the Heat Link. Loose or incorrect wiring can cause communication issues.
Check Fuse or Circuit Breaker: Ensure that the circuit breaker or fuse for the Heat Link is not tripped. If the breaker is tripped or the fuse is blown, it could result in a loss of power to the Heat Link.
Inspect for Damage: Inspect the Heat Link for any visible signs of damage or corrosion. Sometimes, physical damage or corrosion can affect the functioning of the device.
Contact Support: If you've exhausted all troubleshooting steps and the Heat Link is still not functioning, consider reaching out to Nest customer support or the manufacturer for assistance. They might be able to provide further guidance or recommend a solution.
Professional Help: If you're not comfortable working with the wiring or troubleshooting further, it might be a good idea to consult a professional HVAC technician. They can diagnose the issue more accurately and recommend the necessary repairs or replacements.
If, after trying these steps, the Heat Link still doesn't respond or show any lights, it's possible that the Heat Link itself is faulty and needs to be replaced. Before purchasing a new one, though, I recommend confirming with Nest or the manufacturer's support to see if there are any other potential solutions or if they can provide further insights into the issue.
