What warning signs should I watch for around central air conditioner?
Track changes in operation, sound, smell, moisture, temperature, movement, and visible condition around central air conditioner; patterns matter more than one isolated observation.
What this means
Central air conditioner covers cooling performance, cycling, outdoor equipment, and condensate. Relevant observations include Runs but the house stays warm, Will not turn on, Starts and stops rapidly, Water is leaking near the indoor unit, Outdoor unit makes a loud noise. The correct response depends on age, design, climate, usage, installation, recent work, and the exact manufacturer instructions; these observations narrow next steps but do not prove a failed part.
Safe checks
- Compare central air conditioner with a similar unaffected area or a documented normal cycle.
- Note whether these known observations appear: Runs but the house stays warm, Will not turn on, Starts and stops rapidly, Water is leaking near the indoor unit, Outdoor unit makes a loud noise.
- Photograph and date visible changes from a safe position.
Stop and get help if
- Leave for a gas odour or carbon-monoxide alarm; stop for smoke, scorching, damaged wiring, or repeated breaker trips.
- Do not open combustion, refrigerant, high-voltage, or sealed compartments.
Which professional to call
Use a qualified HVAC technician when the condition exceeds safe user access or the visible checks do not explain it.
Find the relevant tradeSource and method
This answer combines HomeSOS's structured triage with safety boundaries supported by a public source. It does not replace inspection.
Health Canada: Home safetyReviewed August 12, 2026