Instant fault code reference and decision-tree troubleshooting for Carrier, Trane, Daikin, Lennox, Goodman, Rheem, York, and 200+ brands. Built for zero-signal mechanical rooms and high-stakes service calls.
Type a code or filter by brand to see immediate symptom definitions and guided check sequences:
A simple code translation tells you what tripped — not why it tripped or what to verify next.
Browse dedicated error code and wiring logic hubs for all premier HVAC manufacturers:
Yes. The ACLogics mobile app incorporates a complete, local SQLite database containing over 10,000 error codes, blink codes, and diagnostic flash sequences across all major residential and commercial HVAC brands. You can search instantly in underground plant rooms, steel mechanical basements, or remote job sites with zero internet latency.
Absolutely. You can search by numeric codes (e.g. "33", "E1"), flash counts (e.g. "4 red flashes, 1 yellow"), or symptom descriptions (e.g. "ignitor clicks but valve fails to open").
Once you select an error code, ACLogics loads an interactive troubleshooting decision tree. It tells you exactly what to measure with your multimeter or manifold gauges, analyzes your reading, rules out impossible causes, and isolates the true root cause in under 3 minutes.
Free for Technicians
Download ACLogics on iPhone, iPad, or Android today. Try for free — no credit card needed. Access full multi-brand error code archives with permanent offline availability.
