AC repair - and when to stop repairing

What is ac repair?

Most air conditioning failures come down to a handful of parts: a failed capacitor, a burnt contactor, a clogged condensate drain, a dirty coil restricting airflow, or a refrigerant leak. The first four are ordinary repairs on any system. The last one is the decision point - a leak on a system past twelve years is usually where repairing stops being worth it.

Signs you need ac repair

• The unit hums but the outdoor fan does not spin - often a capacitor, one of the cheapest common failures
• Air is coming out of the vents but it is not cold
• The system turns on and off every few minutes without ever satisfying the thermostat
• Ice on the refrigerant line or on the indoor coil - almost always airflow restriction or low refrigerant
• Water pooling around the indoor unit, or a ceiling stain below it
• A grinding, screeching or rhythmic clicking noise that was not there last season
• The breaker for the condenser trips and needs resetting more than once
• Cooling is fine, but your electricity bill has climbed with no change in the weather or your habits

Seeing something not on this list? Browse hvac problems by symptom →

How ac repair actually works

1. 1

   Diagnostic visit

   The technician confirms the symptom, checks the thermostat and the filter first, then works electrical and refrigerant side: capacitor and contactor condition, amp draw, static pressure, superheat and subcooling. Most diagnoses are reached in under an hour.

   Watch forA diagnosis delivered without any instrument on the equipment. If nobody put gauges or a meter on it and you are being quoted a compressor, get a second opinion before agreeing to anything.

2. 2

   The diagnostic fee conversation

   Nearly every company charges to come out and diagnose. Many credit it against the repair if you go ahead. Ask which policy applies before booking, and ask whether the fee changes for evenings and weekends.

   Watch forA "free" diagnostic. Diagnosis costs the company real time, so a free one is usually recovered somewhere - most often in a repair quote that arrives higher than it needed to be, or in a replacement pitch.

3. 3

   The repair quote, itemised

   You should get the part, the labour and the warranty on that repair separately. Common repairs - capacitor, contactor, condensate pump, blower capacitor, clearing a drain line - are modest. Compressor and evaporator coil replacements are an entirely different order of expense.

   Watch forA single lump-sum figure with no part named. You cannot judge whether a price is reasonable, or get a comparable second quote, without knowing what is being replaced.

4. 4

   Refrigerant: the question to insist on

   If the system is low on refrigerant, it has leaked, because refrigerant is not consumed. Adding more without finding the leak buys you a season at most. Ask for a leak search - dye, electronic detector or nitrogen pressure test - and for the leak location in writing.

   Watch forA "top-up" offered as the fix, especially as an annual routine. That is a recurring charge dressed up as maintenance. It is also poor practice environmentally, and on older R-22 systems it is expensive enough on its own to change the repair-or-replace answer.

5. 5

   Repair or replace - the actual threshold

   Two things decide it: the age of the system and the size of the repair relative to a new one. Under about ten years, repair almost always wins. Past fifteen, a major repair rarely does. In between, weigh the repair cost against what you would pay for a system that comes with a fresh warranty and lower running cost.

   Watch forA replacement recommendation on the first visit for a system under ten years old, with no part diagnosis offered. That is a sales call with a toolbox.

What does ac repair cost?

Most air conditioning repairs land between $150 and $700, with capacitors and contactors at the low end and refrigerant leak repair or an evaporator coil at the top. Compressor replacement sits well above that and is usually where replacement becomes the better buy.

See the full ac repair cost guide - by material, size and region →

If the number is the problem, here are the ways people pay for it →