AC checklist: getting your air conditioner ready for summer
Inland Sonoma, Marin and Napa can swing from mild to triple digits fast. A spring checklist and tune-up keep your AC ready before the first heat wave.
Updated October 2026 by the Green Core Heating & Air teamGet your AC ready in April or May, before the first heat wave. Put in a fresh filter, clear at least 2 feet around the outdoor unit, rinse off leaves and dirt, check the condensate drain and test the cooling. Then have a technician do a spring tune-up to clean the coils, check refrigerant and test the electrical parts. During summer, check the filter every month or two.
Simple steps that keep your AC ready
No tools needed. These quick habits help your AC cool well and catch problems early.
Every month or two during summer
5 minutes- Check the air filterThe Department of Energy says to clean or replace it every month or two during cooling season, more often with pets or dust.
- Keep the outdoor unit clearPull weeds and move anything stacked against it. Keep plants trimmed back at least 2 feet.
- Check after smoky daysWildfire smoke loads filters fast. Look at the filter after a smoky stretch.
Every spring, before the first heat wave
About 30 minutes- Put in a fresh filterStart the season clean. A clogged filter is one of the most common reasons an AC struggles.
- Clear around the outdoor unitGive it at least 2 feet of space on all sides and plenty of open air above it.
- Rinse the outdoor coil gentlyTurn the power off at the disconnect first, then rinse with a garden hose. Never use a pressure washer.
- Check the condensate drainLook for water in the pan under the indoor unit or a drain line that isn't dripping outside when the AC runs.
- Check the line set insulationThe foam on the larger copper line to the outdoor unit should be intact, not cracked or missing.
- Test the coolingSet the thermostat a few degrees below room temperature. Cool air should come out within a few minutes.
What a spring AC tune-up covers
These checks need gauges and training. They're what we do at every AC tune-up.
- Clean the outdoor condenser coil
- Check the indoor evaporator coil
- Check refrigerant levels
- Test the capacitor and contactor
- Clear the condensate drain line
- Tighten electrical connections
- Check airflow and the blower
- Check the thermostat and the full cooling cycle
Call us if you notice
- Warm air from the ventsOften a failed capacitor, low refrigerant or a dirty coil.
- Ice on the copper lines or coilTurn the AC off and call us. Running it frozen can damage the compressor.
- Water around the indoor unitUsually a clogged drain line.
- Turns on and off every few minutesShort cycling wears parts and wastes energy.
- Buzzing or clicking outsideCan mean an electrical part is failing.
- Breaker keeps trippingDon't keep resetting it. Call us.
Let us handle the spring tune-up every year
Both plans include a cooling-focused spring visit, so your AC is checked before it has to work hard.
Comfort Plus
For furnace, AC or heat pump systems.
- A cooling-focused spring visit and a heating-focused fall visit
- Everything in Essential Care
- Standard filter included and installed at each visit
- Outdoor coil cleaned once a year
- No diagnostic fee, a bigger repair discount and a 72-hour scheduling guarantee on work days
Total Comfort
For furnace and AC systems, or heat pumps. Our most complete plan.
- Comprehensive spring and fall tune-ups, inside and out
- Outdoor coil deep-cleaned at both tune-ups
- We bring and swap your filter every quarter
- No diagnostic fee, a repair discount and a 48-hour scheduling guarantee on work days
- An extra year of warranty on repairs, and the plan transfers if you sell your home
Have a furnace too? Both plans also include a heating-focused fall visit.
Quick answers
When should I service my AC?
In the spring, before the first heat wave. In the North Bay that's usually April or May.
How often should I change my AC filter?
The Department of Energy says to clean or replace it every month or two during cooling season.
Can I hose off my AC unit?
Yes, gently. Turn the power off first, use a regular garden hose and never a pressure washer, which can bend the coil fins.
How much space does my outdoor unit need?
Keep plants and stored items at least 2 feet away so it can move air freely.
Book your spring AC tune-up
Beat the first heat wave. Book now and we'll have your AC ready before summer.
(707) 988-5858Book a tune-up