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AC won't turn on?

Check the thermostat batteries & the float switch by the air handler first. If both are fine it's electrical & we need to see it.

Check these first

Thermostat. Blank screen means batteries. Even a hardwired one can have a backup battery that's dead.
Float switch. A little switch on the drain line at the air handler. If the pan is full it cuts the power on purpose. Full pan? That's the drain line.
Both breakers. One for the outdoor unit, one for the air handler. A tripped breaker sits in the middle, not fully off.
The disconnect by the outdoor unit. The gray box on the wall. Make sure the pull is in & seated.
The air handler door. Many have a switch that kills power when the panel isn't fully closed. Push it shut.

What it usually is

A blown low voltage fuse

A small fuse on the control board. It blows when the thermostat wire shorts, often where a trimmer nicked it outside. We find the short, not just the fuse.

Transformer or control board

The parts that turn house power into thermostat power. When one goes, everything looks dead. Both are repairs.

Thermostat

They do die, & a bad one can leave the whole system sitting there. If it's the thermostat you'll know in the first ten minutes.

Contactor

If the inside runs but the outside never kicks on, the contactor outside is usually stuck or burnt. Quick fix, usually done on the same visit.

What it costs to find out

Residential$95$130 after hours

Commercial$125$160 after hours

Regular hours are Mon to Fri, 7am to 5pm. Dead systems are usually the fastest diagnosis we do. Written price before anything gets fixed.

From the gallery of gross

A float switch full of this is the number one reason a system will not turn on. A capacitor like that is usually number two.

See the gallery of gross

Storm season tip. A surge protector at the outdoor unit protects the compressor & control boards from power spikes. Homes & businesses.

Questions people ask

Blower, blower motor or the control board inside. Turn it off so the coil doesn't freeze while you wait on us.

Batteries first. If new batteries don't bring it back, the transformer or that little fuse is the next guess, & that's a service call.

A fuse, a thermostat or a contactor, yes, every time. A control board on a 15 year old system, we'll put the replacement number next to it & you decide.

Think comfort. Think Aphex.