Diagnose faster, and fix it right the first time.
Use the troubleshooter, search a fault code, or pull up field cases and service guides. Check model-specific details against the equipment manual before making changes.
- Decision points
- 33
- Decision points
- Field cases
- 71
- Field cases
- Knowledge guides
- 73
- Knowledge guides
From service call to service report
Record it once. Build a clearer handoff.
Start free with references, calculators, and diagnostic sessions. Upgrade when you need unlimited saved sessions and reporting tools for your daily work.
Capture the checks
Use the diagnostic workflow and save up to 3 sessions with a free account.
Keep the job history
Pro removes the saved-session limit so you can reopen readings and notes across visits.
Finish the paperwork
Pro turns recorded readings into editable reports, with maintenance worksheets, text download, and print options.
What do you need to check?
Start with the symptom, the equipment, or the reference you need.
Guided Troubleshooter
Work through the symptom one check at a time.
OpenField Cases
See what was found, measured, repaired, and left for follow-up.
OpenFault Codes
Search the codes we have documented, then verify the exact model manual.
OpenTechnician Tools
Field calculators for electrical, refrigeration, airflow, and static pressure checks.
OpenKnowledge Base
Service guides on common procedures, controls, airflow, refrigeration, and diagnostics.
OpenRefrigerant Reference
Charging context, blend handling, and refrigerant notes without pressure-only shortcuts.
OpenService calls from the field
Complaint, readings, checks, what was actually confirmed, and what happened next.
Replacement compressor trips the breaker: verify voltage before condemning the part
The system tripped its breaker after a replacement compressor was installed.
Condensate overflow returns after a pan adjustment: investigate the connected drain
Water leakage returned the day after drain-pan support and pitch were adjusted.
Mini-split water leak caused by condensate restriction and sweating line
Indoor mini-split was dripping water from the supply-air area.
Need the longer write-up?
The Knowledge Base covers repeat service problems with step-by-step checks. Field Cases stay separate so one job does not get treated like a rule for every unit.
Safety note
HVAC work can involve high voltage, rotating equipment, pressurized refrigerants, and combustion systems. Use this site as a reference only. Follow the equipment manual, applicable codes, PPE, lockout/tagout, and current refrigerant rules. Field cases and troubleshooting paths are case-specific and are not OEM procedures or universal targets.