Honeywell Thermostat Error Codes & Fix Guides
All FixCode Guide coverage for Honeywell thermostat error codes: start with the complete code list, or jump to a deep-dive guide for a specific code. Everything is verified against Honeywell manufacturer documentation.
Guides in this section
Honeywell Thermostat Error Codes List: Every Alert Code ExplainedHoneywell Thermostat Service Codes (164, 168, 170, 173): Meaning & FixesHoneywell Thermostat Filter & Maintenance Codes (181, 182, 184, 185, 187, 188): Meaning & FixesHoneywell Thermostat Wi-Fi & Registration Codes (210, 388, 399, 400, 508): Meaning & FixesHoneywell Thermostat 175 Code: What 'AC Power Resumed' Means & What To Do
Most searched Honeywell thermostat codes
| Code | Meaning |
|---|---|
| 175 | AC power resumed — Resideo's Lyric T6 Pro Wi-Fi table words it: 'AC power to the thermostat was restored after a power failure. You don't need to take any action.' The T6 Pro Smart guide's Alert Code Reference carries the same entry: 'AC Power Resumed — No action needed. Power restored after loss.' |