AC Won't Turn On? What to Check
When an air conditioner will not start, the cause is often electrical or a safety switch.
Common causes
Tripped breaker or blown fuse
The most common simple cause.
Thermostat issues
Dead batteries, wrong settings or failure.
Float switch or safety shutoff
A clogged drain can trigger a shutoff.
Failed capacitor or contactor
The outdoor unit will not start.
Control board or transformer failure
The system receives no signal or power.
What you can safely check
- Check thermostat settings and batteries.
- Check the breaker once. If it trips again, do not keep resetting it.
- Look for water near the indoor unit.
When to call a professional. Call a technician if the breaker trips repeatedly or the system does not start. Never open electrical panels or remove access covers on equipment. If you smell burning or see smoke, turn off power and call 911 if there is any danger.
Should I keep resetting the breaker?
No. A breaker that trips repeatedly signals a problem.
Is this an emergency?
In extreme heat, yes. We accept 24/7 emergency calls.
Could the drain be the problem?
Yes. A full drain pan can trip a safety switch.
Next steps and related help
Comfortable again, without the runaround
$30 off your first service call. Mention this website when scheduling. Cannot be combined with other offers. Excludes diagnostic fee and maintenance visits.