When your Aliso Viejo AC runs but the house stays warm
A lot of Aliso Viejo homeowners call us with the same complaint each fall. The thermostat is set to 72, the outdoor condenser is humming, air is blowing from the vents, and the house just won’t get below 78. The AC isn’t broken in an obvious way, which makes it harder to diagnose.
What usually causes this
Nine times out of ten on a call like this, it’s one of four things:
- Low refrigerant from a slow leak in the line set or evaporator coil
- A dirty evaporator coil that can’t transfer heat (very common in homes with poor return filtration)
- A failing capacitor on the outdoor unit causing the compressor to short-cycle
- An undersized or oversized system that was wrong from the day it was installed
The fourth one is more common than people expect in Aliso Viejo. A lot of the tract homes here had systems swapped out by a previous owner who picked the cheapest bid, and a 2-ton unit ended up in a 1,900 sq ft house.
What to expect when we come out
We bring gauges and a leak detector to the diagnosis. If it’s a charge issue we’ll measure superheat and subcool, find the leak, and quote the fix. If it’s the coil, we pull the access panel and inspect. Most diagnostics take 45-60 minutes. We don’t charge to give you a written estimate after the diagnostic.
If you’re in Aliso Viejo and your system is over 12 years old, ask us about AC repair vs replacement — sometimes the math works one way, sometimes the other.