AC Running but Not Cooling? Start Here
Your air conditioner is on, the fan is blowing, but the house isn’t getting cooler. In the Lower Mainland this usually shows up on the first hot week of summer, when a system that sat idle all year suddenly has to work hard. Many causes are simple and you can check them yourself in ten minutes. Others need a licensed technician. This guide walks through both.
Check these first (10 minutes)
- Thermostat. Make sure it’s set to Cool, not Fan or Heat, and the setpoint is a few degrees below room temperature. Replace the batteries if the screen is faint.
- Air filter. A clogged filter is the most common cause of weak cooling. It chokes airflow and can freeze the indoor coil. Replace it. See furnace filter replacement.
- Outdoor unit. Is the fan on top spinning? Is the coil covered in cottonwood fluff, leaves or grass clippings? Turn the power off at the disconnect and gently rinse the coil from the inside out with a garden hose. Don’t use a pressure washer.
- Breakers. AC systems usually have a breaker for the outdoor unit and one for the furnace or air handler. If the indoor fan runs but the outdoor unit is silent, the outdoor breaker may have tripped. Reset it once. If it trips again, stop and call us.
- Vents and returns. Open the supply registers and keep furniture and rugs off the return grilles.
What the symptoms usually mean
| What you notice | Likely cause | DIY or technician? |
|---|---|---|
| Air from vents is barely cool, outdoor unit running | Low refrigerant (leak), dirty coil, weak capacitor | Technician |
| Ice on the copper line or indoor coil | Low airflow (filter, blower) or low refrigerant | Turn the AC off to thaw; check the filter; call if it returns |
| Outdoor unit hums but the fan doesn’t spin | Failed capacitor or fan motor | Technician |
| Outdoor unit completely silent | Tripped breaker, failed contactor, thermostat wiring | Check the breaker once; then technician |
| Cools in the morning, falls behind in the afternoon | Undersized system, dirty coil, attic heat, leaky ducts | Technician to assess |
| Upstairs hot, downstairs cold | Duct design, one system serving two floors | Balancing or zoning; see heat pump options |
| Water around the furnace | Blocked condensate drain | See AC leaking water |
Low refrigerant is a leak, not a top-up
An air conditioner doesn’t use up refrigerant. If the charge is low, there is a leak somewhere. Adding refrigerant without finding the leak gets you through a few weeks, and then you’re paying again. We check pressures, find the leak, explain whether the repair is worth it on an older system, and only then recharge.
Is it time to repair or replace?
Repair usually makes sense for a newer system with a single failed part such as a capacitor, contactor or fan motor. Replacement is worth considering when the system is 12–15 years old or more, uses the old R-22 refrigerant, has a major leak in the coil, or the compressor has failed. If you’re replacing, a heat pump gives you the same cooling plus efficient heating, and may qualify for rebates.
Prevent it next summer
- Book an AC tune-up in spring, before the first heat wave
- Change the filter every 1–3 months during cooling season
- Keep 60 cm of clear space around the outdoor unit and rinse the coil once a year
- Close blinds on south- and west-facing windows during heat waves
Still not cooling?
We repair central air conditioners, ductless systems and heat pumps across Greater Vancouver, 7 days a week. AC repair · Vancouver · Surrey · Richmond · Burnaby