Getting Your AC Ready for a Colorado Summer

The first 90-degree day in Denver usually shows up in late May or early June, and it always seems to catch people off guard. Air conditioners that sat silent through the winter suddenly have to run for hours, and the ones that were not ready tell you about it fast. Our phones ring nonstop that week. The good news is that most of those calls could be prevented with a little spring prep, and a lot of it you can do yourself on a Saturday morning.

Here is how our crews get a central air system ready for summer, broken into what you can safely handle and what is better left to a licensed technician.

Why spring prep matters more along the Front Range

Colorado is hard on outdoor equipment in ways that surprise people who moved here from somewhere humid. Spring hail can flatten the thin aluminum fins on a condenser coil in a single afternoon. Cottonwood fluff blankets coils across the metro every May and June. Big temperature swings mean an AC may run on a 75-degree afternoon and sit next to frost the following morning. And at our altitude, a system has to move more air to do the same amount of cooling, so a small restriction in airflow shows up faster as poor performance.

A system that starts the season clean and properly charged runs shorter cycles, cools more evenly and is far less likely to quit on the Fourth of July.

Your homeowner checklist

Before you start, turn the system off at the thermostat, and then switch off the outdoor disconnect. That is the small gray box mounted on the wall near the condenser. Some have a pull-out block, others have a lever. If you are not sure, leave the electrical alone and stick to the steps that do not need it.

1. Replace the furnace filter. Your AC uses the same blower and filter as your furnace. A filter that made it through the heating season is probably done.
2. Clear two feet around the condenser. Pull weeds, trim shrubs and move the patio furniture or grill away from the unit. It needs room to breathe.
3. Remove any winter cover. If you covered the unit for winter, take the cover off completely. Running an AC with a cover on it can damage the compressor in minutes.
4. Rinse the coil gently. With the power off, spray the fins from the outside in using a garden hose on a soft setting. Never use a pressure washer. It folds the fins flat.
5. Check the condensate drain. Find the white PVC pipe near the indoor coil and make sure it is not clogged. Pouring a cup of white vinegar into the access port helps prevent algae buildup.
6. Open the supply vents. Many people close upstairs vents in winter. Open them all back up before summer.

When you are done, turn the disconnect back on, wait 30 minutes, and then set the thermostat to cool a few degrees below the room temperature. Let it run for 15 minutes and check the air coming from a vent near the furnace. Listen to the outdoor unit while it runs, too. A steady hum and the whoosh of the fan are normal. Rattling, grinding or a loud buzz that never settles are worth a call. It should feel noticeably cool, usually 15 to 20 degrees cooler than the air going into the return.

What a technician checks that you cannot

Some parts of an AC tune-up need gauges, meters and training. When one of our technicians does a spring check, these are the items on the list:

Refrigerant charge. We measure superheat or subcooling to confirm the system has the right amount of refrigerant. Low charge almost always means a leak, and adding refrigerant without finding the leak just postpones the next breakdown.

Capacitors. These small cylinders give the compressor and fan motor the jolt they need to start. They are the number one failed part we replace in summer. A weak capacitor can test fine in April and fail in July, so we measure it against its rating and replace it if it has drifted more than about 10%.

Electrical connections and contactor. Loose wires and pitted contacts cause overheating and nuisance trips. We tighten and inspect each one.

Indoor coil and blower. A dirty evaporator coil or blower wheel cuts airflow, and low airflow at altitude can lead to a frozen coil on the first hot week.

A forty-dollar capacitor is the difference between a quick spring visit and a no-cool call on the hottest Saturday of the year. We would much rather find it in April.

Marcus Reyes, Founder

Hail and cottonwood: two Denver problems

If a hailstorm has rolled through your neighborhood, walk out and look at the condenser. Flattened fins on one side are common. A small amount of fin damage is mostly cosmetic, but if more than a third of the coil face is crushed, airflow drops and efficiency drops with it. A technician can straighten minor damage with a fin comb. Heavy damage may be worth documenting for your homeowners insurance claim along with your roof.

Cottonwood season is the other one. The fluff gets pulled into the coil and mats down like felt. A quick hose rinse once a week during peak season keeps it from building up. Some homeowners add a removable mesh screen around the unit in May and pull it off after the trees finish. If you do that, make sure it is a fine mesh designed for the purpose and that it stays a few inches away from the coil.

Signs you should call before summer arrives

Run your AC for a short test on the first warm spring day. Call for service if you notice any of these:

The outdoor fan does not spin, or spins slowly. The unit hums but the compressor does not start. Breakers trip when the AC turns on. You see ice on the copper lines or the indoor coil. Water is pooling around the furnace. The system runs for a long time but the house barely cools.

Each of those is easier, faster and usually cheaper to fix in May than in the middle of a July heat wave, when parts are on backorder and every company in town is booked out.

Thinking about replacing an older system?

If your AC is more than 15 years old and still uses the older R-22 refrigerant, spring is a good time to plan. Recharging an R-22 system is very expensive now, and a leak can turn a repair into a replacement overnight. Replacing on your schedule in spring gives you time to compare options, including heat pumps that can also handle a share of your heating. We are always glad to talk through the numbers with no pressure either way.

If you would like us to handle the technician side of your spring check, you can book online or call us at 555-0142. Our maintenance plan members get first pick of spring appointments, but we keep slots open for everyone through early June.