Pre-Summer AC Tune-Up Checklist
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Most AC breakdowns we see around Portland, Gresham, and Beaverton don't happen in May. They happen on the first truly hot afternoon of the year, when a system that sat idle all winter gets asked to run for ten hours straight. The capacitor that was already weak gives out, the coil that collected a season of cottonwood fluff can't shed heat, and the call comes in at the same moment everyone else's call comes in.
A tune-up before the season is how you move that failure from a heat wave to a calm spring morning, or avoid it altogether. Some of the checklist is yours, and you can knock it out in an afternoon. The rest needs meters, gauges, and someone who knows what the readings mean. Here's how we split it.
The short answer
Bottom Line Up Front
Swap the filter, clear the registers, change the thermostat batteries, clean up around the outdoor unit, and check the drain line yourself. Leave the capacitor, wiring, refrigerant charge, and coil cleaning to a technician, and get it done before the first hot week.
A pre-summer tune-up is two jobs. Yours takes an afternoon and costs little more than a filter. Ours takes meters and gauges, and it's how weak parts get caught in spring instead of failing in July, when every HVAC company in the metro is booked.
on a recent AC service call
we make it right at no charge
included
The rest of this post walks through both halves of the checklist, what a technician is actually looking for, and a decision matrix at the end for the problems you might find along the way.
Part 1: What you can check yourself this weekend
None of this needs tools beyond a flashlight and a pair of gloves, and none of it involves opening an electrical panel. Start inside: pull the return grille and look at the air filter. If it's gray, matted, or bowed out of its frame, replace it. A clogged filter starves the system of air, makes the blower work harder, and lets dust get past into the coil. Note the size printed on the frame so you buy the right one next time.
Next, walk the house and look at every supply register and return. Rugs, couches, and boxes stacked against a wall vent are more common than you'd think, and a blocked register makes one room run hot while the system keeps running to catch up. Then check the thermostat. A lot of thermostats run on AA batteries, and weak batteries can make a perfectly good system look dead.
Outside, look at the condenser. Leaves, grass clippings, and fluff pile up against the fins and sometimes inside the cabinet. Switch the unit off at its outdoor disconnect first, then clear what you can reach from outside by hand, and trim back shrubs so the unit has room to breathe. Finally, find where the condensate line drains and make sure it isn't clogged or sitting in a puddle that never dries.
If the AC won't come on at all, look at the breaker and the thermostat batteries first, and listen to whether the outdoor fan is spinning. When you call us, we'll talk through those same things over the phone, because sometimes the answer is a tripped breaker and nobody needs to drive out.
Part 2: What a technician should test during a tune-up
This is the half you can't see from the driveway. A real tune-up is measured, not eyeballed. The capacitor gets tested with a meter, because a weak one is one of the most common reasons an AC struggles to start or quits cooling. The contactor and wiring get checked for pitting, loose connections, and burned insulation. Amp draw on the compressor and fan motors gets compared against the nameplate.
On the refrigerant side, gauges go on the service ports to read pressures and line temperatures, so we can tell whether the system is charged correctly or slowly leaking. Inside, we measure the temperature of the air going into the system and the air coming out of the registers. That split, along with humidity readings, shows whether the system is actually cooling and pulling moisture out of the house the way it should.
The coil gets cleaned, the condensate drain gets cleared and tested, and the data plate gets read so we know the age of the equipment and what refrigerant it runs on. That last part matters more than it sounds: a system that still runs on R-22 uses a refrigerant that's been phased out, which makes recharging it harder and more expensive every year. If that's what we find, we'll tell you plainly and walk you through your options. For a fuller picture of what goes into a visit, see our HVAC maintenance service.
Your list vs. ours at a glance
Each row is one item from a full pre-summer checklist. The highlighted column is who should handle it.
| Checklist item | You can do it | Leave it to a technician |
|---|---|---|
| Air filter | Check and replace it | Checked again during the visit |
| Registers and returns | Move rugs, furniture, and boxes | Airflow measured if rooms stay hot |
| Thermostat | Fresh batteries, correct mode | Wiring and calls tested |
| Outdoor unit surroundings | Power off, clear leaves, trim shrubs | Inside of the cabinet cleaned out |
| Condenser coil | Clear loose debris from outside | Proper cleaning of packed fins |
| Capacitor and contactor | Don't touch | Tested with a meter |
| Refrigerant charge | Can't be checked by eye | Pressures and temperatures read |
| Condensate drain | Look for clogs or standing water | Line cleared and pump tested |
Your pre-summer homework
An afternoon, a new filter, and a flashlight. No panels opened.
What to check
- The filter is clean and seated flat in its frame, not gray, matted, or bowed.
- Every register and return in the house is open and clear of rugs, furniture, and boxes.
- The thermostat has fresh batteries and is set to cool.
- The outdoor unit has leaves and clippings cleared away, with the power off at the disconnect first.
What a tune-up covers
The measured half of the checklist, done with meters and gauges.
What we test
- The capacitor reads within spec and the contactor isn't pitted or burned.
- Refrigerant pressures and line temperatures show the system is charged correctly.
- The temperature split between return and supply air shows it's really cooling.
- The coil is clean, the drain is clear, and the data plate tells us the equipment's age and refrigerant.
Don't skip the drain line
Your AC pulls water out of the air, and that water has to go somewhere. In a lot of Portland-area homes it runs through a condensate line or a small condensate pump in a garage, basement, or crawlspace. When the line clogs or the pump fails, the result can be water damage, a system that shuts itself off, or both. We once traced a furnace another company had tagged out back to a condensate pump whose contacts had corroded so badly it couldn't pass 24 volts downstream. Small parts like that are easy to overlook and worth checking every season.
A tune-up should tell you what your system needs, not what someone wants to sell you. If the only option you're given is replacing the whole system, get another opinion. We've followed two other companies on a call where both said the equipment was too old and had to go; the real problem was an undersized breaker. Get multiple quotes, listen for whether the explanation makes sense, and trust your gut if something feels off. Our post on getting a second opinion before replacement goes deeper.
“The point of a tune-up isn’t to find something to sell. It’s to find the weak part before the first hot week finds it for you.”— Talon Mechanical
Smoke season and your filter
Summer in the Portland metro can mean smoky weeks, and smoke loads filters faster than ordinary dust. If the air turns hazy, check the filter more often than you normally would and keep a spare on hand. We cover the rest of it in wildfire smoke and your HVAC.
The decision matrix
Found something while you worked through your half of the list? Find it in the left column and see whether it's a do-it-yourself fix or a reason to call.
| If your AC… | Handle it yourself | Call us |
|---|---|---|
| has a gray, clogged filter | Yes, swap it | Not needed |
| won't turn on at all | Check breaker and batteries | If that's not it |
| has leaves piled around the outdoor unit | Yes, power off first | If it's inside the cabinet |
| runs but blows warm air | No | Yes |
| hums but the outdoor fan won't spin | Electrical, hands off | Yes |
| has ice on the lines or coil | Turn it off and let it thaw | Yes |
| is leaving water where it shouldn't | Check the drain line | If it keeps happening |
| still runs on R-22 | No | Talk through options |
The bottom line
Do your half of the checklist in the spring: a fresh filter, clear registers, fresh thermostat batteries, a clean area around the condenser, and a drain line that's actually draining. Then have a technician measure what you can't see: the capacitor, the electrical connections, the refrigerant charge, the temperature split, and the coil. Together, that's the best chance your AC has of making it through summer without a breakdown.
If your system is already acting up, our AC repair page covers how we diagnose problems, and if it's near the end of its life, our guide on when to replace your AC will help you weigh it. When you're ready, book your tune-up before the first heat wave does it for you.
Questions This Post Tends to Raise
Before the cooling season starts, while the weather is still mild. That way any weak part gets replaced on a calm day instead of failing during the first heat wave, when everyone else is calling too. You can book a visit online.
Often, yes. We'll walk you through a few checks over the phone, like whether the breaker has tripped and whether the outdoor fan is running. Sometimes that solves it, and if it doesn't, we'll know more about what we're looking at before we arrive.
We offer free onsite diagnostics. Terms and conditions may apply, so call (503) 334-9584 for details on your address.
Our work comes with a 30-day guarantee. If we fixed it incorrectly, we come back and make it right at no charge. If an older system develops a new, unrelated problem, we'll explain the difference before any work is done.
It's worth knowing where it stands. R-22 has been phased out, so topping it off gets harder and more expensive. A tune-up tells you whether the system is holding its charge and running well, which is the information you need to decide between keeping it going and looking at AC replacement.
Yes. We service commercial rooftop and packaged units, including belts, filters, electrical components, and refrigerant checks. See our commercial HVAC page for more.
You can call us any time, and we handle emergencies outside normal hours. Call (503) 334-9584 any time, or read more about our emergency HVAC service.
How your AC moves heat, which parts wear out first, and what a tune-up actually checks.
How to tell if your heating or cooling problem can't wait, and what to check first.
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Free onsite diagnostics; terms and conditions may apply, so call for details.