Wireless Honeywell Home smart thermostat shows 'No Signal' or 'Lost Connection' to wireless receiver or RedLINK gateway

Safety: Turn off power to the HVAC system before opening any equipment panels.

• Verify receiver power: Check the Honeywell Home wireless receiver module at the furnace/air handler. Ensure its status LED is on and the 24VAC power connections (R and C) are secure.
• Reduce distance and obstacles: If the thermostat is far from the receiver or separated by metal ducts or concrete walls, relocate the receiver or thermostat to improve line‑of‑sight.
• Check for interference: Move cordless phone bases, Wi‑Fi routers, and large electronics away from the receiver and thermostat if they are very close.
• Re‑pair devices: Put the receiver into pairing mode (per Honeywell instructions) and re‑register the thermostat. Confirm that the receiver LED indicates a successful link.
• Replace receiver or thermostat radio: If pairing repeatedly fails and power is confirmed, the wireless radio in the receiver or thermostat may be defective. Replace the Honeywell wireless receiver module or thermostat as needed.