What actually causes an AC to stop cooling?
An air conditioner that is not cooling looks the same from the thermostat whatever the cause. At the equipment it looks very different. The fault usually sits in one of a handful of places, and an inspection is what tells us which one you are dealing with.
- Electrical components. A failed capacitor or contactor is one of the more common reasons a system hums but will not start, or starts and drops out again.
- The blower or condenser fan motor. If air is not moving, cooling capacity goes with it even when the rest of the system is healthy.
- Refrigerant charge. Low charge is a symptom rather than a cause. Refrigerant does not get used up, so if the charge is low there is a leak to find.
- Coils. A dirty condenser coil cannot reject heat, and a frozen evaporator coil stops airflow. Ice on the system usually points back to airflow or charge.
- Controls and the thermostat. Sometimes the equipment is fine and the signal telling it what to do is not.
- Ductwork. If the equipment is working but certain rooms never get comfortable, the problem may be in how the air is being delivered.
What does the $139 diagnostic visit cover?
We come out, inspect the system and tell you what we find. That is the $139 visit. It is a fixed, visible price so you know the cost of getting an answer before you commit to anything.
If you book the repair with us, the $139 diagnostic fee is waived.
Should this be repaired or replaced?
Not every cooling fault means a new system. A capacitor on an otherwise healthy unit is a different conversation from a failed compressor or a leaking evaporator coil on equipment that has needed attention for several seasons.
What matters is the specific fault, the condition of the rest of the equipment, the repair history, and how the cost of the repair compares to the cost of replacing. We will walk through that with you rather than leading with the larger sale.
If replacement does turn out to be the better option, read about full system replacement and AC replacement, or work through the repair or replace guide.
What will this cost?
The diagnostic visit is $139, waived when you book the repair. Beyond that, the cost depends entirely on what we find. Two owner supplied figures that come up often:
- Refrigerant recharge is priced after we have seen the system and know which refrigerant it takes.
- A complete new system is quoted after we have assessed your home and the scope of the work.
These are typical ranges, not quotes. Final scope and price are confirmed after an assessment. The pricing page has the full picture.
What happens after you get in touch?
- Call or text us, or send a request describing what the system is doing.
- We get back to you to ask a few questions and agree a time.
- We inspect the system on the $139 diagnostic visit.
- We explain what we found and what the options are, with the price agreed before any work begins.
- You decide. If we find something beyond what we quoted, we stop and show you before touching it.
What can you check before calling?
A couple of things worth checking, and neither requires opening anything up:
- The air filter. A badly clogged filter restricts airflow and can cause a system to freeze up or short cycle.
- The thermostat. Confirm it is set to cool and the batteries are good.
- The breaker. If it has tripped, note that it tripped and tell us. A breaker that trips repeatedly is telling you something and should not simply be reset over and over.
Beyond that, leave it alone. Refrigerant and the electrical side of an air conditioner are not homeowner territory, and a capacitor can hold a charge even with the power off.
Repair or replace: how we weigh it
| What we look at | Points toward repair | Points toward replacement |
|---|---|---|
| What failed | A wear item such as a capacitor, contactor or fan motor | Compressor, leaking evaporator coil or cracked heat exchanger |
| Repair history | First real fault the system has had | Repairs stacking up across recent seasons |
| Condition of the rest | Remaining equipment looks sound | Several components visibly tired |
| Cost comparison | Repair sits well below replacement cost | Repair approaches a meaningful share of replacement |
| Comfort history | System kept the house comfortable until now | It never really kept up, which may be sizing or ductwork |
No formula decides this. We look at your equipment and explain what we find. See the repair or replace guide for the longer version.
Common questions
How much does AC repair cost?
It starts with a $139 diagnostic visit, which is waived when you book the repair. The repair cost itself depends on what we find, and we agree the price with you before starting the work.
Why is my AC running but not cooling?
The most common causes are a failed electrical component, a fan or blower motor problem, low refrigerant charge from a leak, or a dirty or frozen coil. They present the same way at the thermostat, so an inspection is what separates them.
Do I need to be home for the visit?
Yes. We need access to the indoor equipment and the thermostat as well as the outdoor unit, and we will want to walk you through what we find.
Can you just add refrigerant?
Refrigerant is not consumed in normal operation, so a low charge means there is a leak. Adding refrigerant without addressing the leak means you will be back in the same position, so we look for the cause first.
Do you work on commercial air conditioning?
No. We work on residential systems only. That means homes, not rooftop units or commercial equipment.
Reviewed and updated September 2026. Prices shown are owner supplied typical ranges, confirmed after an assessment. If anything here looks out of date, call (615) 400-4993 and tell us.