Everything AC DIY by Reputable Roofing
Start Diagnosis

AI HVAC Diagnostic Instrument

Stop guessing.
Start diagnosing.

Tell it what your AC or heating system is doing — the sound, the smell, the temperature, the timing — and get a technician-grade diagnosis: the likely cause, the exact steps to check it, and an honest call on whether it's a DIY fix or a job for a licensed pro.

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GUESS CHECK FOUND

Every diagnosis moves left to right

Symptom-first triageDiagnostic paths built around what you're seeing, hearing, and feeling at the unit — not generic FAQ answers.
EPA 608 awareFlags refrigerant-handling steps that legally require an EPA-certified technician, every time.
Every system typeCentral split systems, heat pumps, mini-splits, window units, gas & electric furnaces, package units.
Safety-gatedElectrical, gas, and refrigerant steps come with a stop-and-check before you touch anything.

Live Diagnostic

Ask it anything about your system

Pick your system type below, then describe the problem in your own words. The more detail you give — sounds, smells, timing, what the thermostat shows — the sharper the diagnosis.

Everything AC DIY AI · Diagnostic Session
Describe the problem and I'll start narrowing it down. Example: "AC runs constantly but the house won't get below 78°F, and there's ice on the copper line outside." If it's an emergency — gas smell, smoke, sparking, or a CO alarm — stop reading this and get out of the house, then call 911 or your gas utility from outside.

Informational only — not a substitute for a licensed HVAC technician. Photos and reference images use extra Workers AI capacity — see footer disclaimer.

How It Works

Three steps to a real answer

01

Describe the symptom

Plain language, no jargon required. Sound, smell, timing, what the thermostat shows — whatever you noticed.

02

Answer a few targeted questions

System type, what you hear or feel at the unit, any error codes. Usually two or three questions, not twenty.

03

Get your verdict

Ranked likely causes, exact steps to check each one, tools you'll need, and a clear DIY-safe or call-a-pro call.

Repair Library

Browse by category

Every diagnostic conversation draws on the same library you can read on your own.

Cooling Problems

No cool air, warm air, weak cooling, frozen coils, and short cycling on AC and heat pump systems.

Split systems · Heat pumps · Mini-splits

Heating Problems

No heat, pilot light and ignition issues, tripped limit switches, and heat pump defrost problems.

Gas & electric furnaces · Heat pumps

Airflow & Ductwork

Weak airflow, uneven rooms, clogged filters and coils, blocked vents, and duct leaks.

Filters · Blowers · Ducts

Noises & Vibration

Buzzing, clicking, banging, squealing, and rattling — matched to what's actually causing them.

Fans · Compressors · Ductwork

Thermostats & Controls

Blank screens, Wi-Fi thermostat pairing, wiring, scheduling quirks, and short-cycling causes.

Smart & manual thermostats

Electrical & Capacitors

Breakers, capacitors, contactors, and disconnects — with a hard line on what's DIY and what isn't.

Breakers · Capacitors · Contactors

Before You Touch Anything

Three lines this tool won't cross

Refrigerant

EPA Section 608

Handling or recovering refrigerant legally requires EPA certification. The tool will identify when refrigerant is the likely issue and point you to a licensed tech — never DIY steps for it.

Electrical

Power off first

Any step near wiring, capacitors, or the disconnect box starts with cutting power at the breaker and confirming it's off. No exceptions, no shortcuts.

Gas & CO

Evacuate, don't diagnose

Gas smell, smoke, or a carbon monoxide alarm is never a diagnostic conversation. Get out, then call 911 or your gas utility from a safe distance.

Full Safety Center →