Independent US HVAC & home energy intelligence
Source-checked specificationsOur methodologyContact
Start here Build my project
EXPLORECOOLCentral ACZONEMini-splitHEATHeat pumpsPOWERSolarSEALInsulationWATERWater heatersFIXHVAC service3XGet quotes
HVAC SYMPTOM LIBRARY

Start with what the system is doing.

Use a symptom guide to capture safe observations, recognize shutoff signals and prepare a written service brief. A symptom page never claims to diagnose the failed part.

Run AC safety triage →Emergency replacement mode
Problem-first research

Seven common entry points.

Each guide leads to the same real decision tools and keeps electrical, refrigerant, combustion and mechanical work with qualified professionals.

WARM-AIR TRIAGEAC Blowing Warm Air: Safe Checks and Repair QuestionsOpen safe guide →ICE / AIRFLOWFrozen AC: Safe Shutoff Steps and Service EvidenceOpen safe guide →CONDENSATE / WATERAC Leaking Water: Drainage Safety and Service ChecklistOpen safe guide →RUN-TIME PATTERNAC Short Cycling: Timing Log and Contractor QuestionsOpen safe guide →NOISE / MECHANICALLoud HVAC Noise: Shutoff Signals and Diagnostic ChecklistOpen safe guide →NO-HEAT SAFETYFurnace Not Heating: Safe Checks and Combustion WarningsOpen safe guide →HEAT-PUMP TRIAGEHeat Pump Not Heating: Defrost, Backup Heat and Service QuestionsOpen safe guide →
Immediate danger

For fire, gas, carbon-monoxide concerns or immediate danger, leave the danger area and call 911. During dangerous heat or cold, prioritize a safe conditioned location and local emergency guidance.