3 Reasons Your AC Stopped Working in the Summer Heat

It happens fast.

The system was running fine last week. Now it's not keeping up, cycling on and off without cooling, or not turning on at all. And of course it's the middle of summer in Hampton Roads.

Most summer AC failures aren't random. They follow patterns.

Here are the three most common reasons we see systems fail during peak summer heat — and what to do if you're dealing with one right now.

1. A Failing Capacitor-One of the Most Common Reasons AC Stops Working in the Summer

The capacitor is one of the most common reasons an AC stops working in summer — and also one of the most replaceable.

It's a small cylindrical component that gives the compressor and fan motors the initial jolt of electricity they need to start. Think of it like the starter on a car.

Capacitors wear out gradually, but heat accelerates the process. They're rated for a certain number of start cycles, and during a Hampton Roads summer when your system is starting and stopping dozens of times a day, a capacitor that was already aging can fail quickly.

Signs of a failing capacitor: the system hums but doesn't start, the outdoor fan runs but the compressor doesn't, or the system starts briefly and shuts off again.

A qualified technician can test it in minutes. If it's the culprit, a capacitor replacement is one of the more straightforward repairs we make.

2. Low Refrigerant from a Leak

Refrigerant doesn't get used up — it circulates in a closed loop. If your system is low on refrigerant, there's a leak somewhere in the system.

And low refrigerant in summer heat means the system can't transfer heat effectively, which causes it to run constantly, freeze up, or eventually stop cooling altogether.

In Hampton Roads, refrigerant leaks tend to get noticed in summer because that's when the system is working hardest. A system that was slightly low in May might limp along until July when the heat load is too much to overcome.

Signs of low refrigerant: the system runs constantly but the house doesn't cool, you notice ice forming on the refrigerant lines, or there's a sweet chemical smell near the indoor unit.

Low refrigerant needs to be diagnosed and repaired by a certified technician — adding refrigerant without finding and fixing the leak is only a temporary solution.

3. A Dirty or Frozen Evaporator Coil

The evaporator coil sits inside your air handler and absorbs heat from the air as it passes over the coil.

When the coil gets coated in dust and debris — or when airflow is restricted by a clogged filter — it can freeze over.

A frozen coil can't absorb heat, which means no cooling, and running a system with a frozen coil risks damaging the compressor.

This is one of the most preventable summer failures. A clean filter and adequate airflow are the main defenses against coil freeze.

If your system is blowing warm air or barely moving air at all, check the filter first. If it's clogged, replace it and turn the system off for a couple of hours to let the coil thaw before restarting.

If the filter is clean and the coil is still freezing, there's likely a deeper issue — low refrigerant, a blower motor problem, or restricted ductwork — that needs professional attention.

If your system has stopped working or isn't keeping up with the summer heat, Comfort Technology serves Hampton, Newport News, Chesapeake, Norfolk, Williamsburg, and the surrounding Peninsula and Hampton Roads area.

Call us at 757-599-9700 or schedule online at comforttechnologyinc.com.

Not sure if it's worth repairing or time to replace? Download our free guide — Repair or Replace?

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