Which components fail most often?
- Capacitor. Provides the electrical kick that starts motors. A failing one shows up as a system that hums but will not start, or starts and drops out. One of the most common calls in the trade.
- Contactor. The switch that brings the outdoor unit on. Contacts pit and burn over time, producing intermittent behaviour that is easy to misread as something larger.
- Blower motor. Moves air through the ducts. When it fails there is no delivery, whatever the rest of the system is doing.
- Condenser fan motor. Without it the outdoor unit cannot reject heat, and the system will struggle then shut down.
Does a failed component mean a new system?
These are repairs, not replacements. A failed capacitor on otherwise sound equipment is not a reason to replace a system, and we will say so.
“If a repair will get you through the season, we will tell you, even when a new system is the bigger sale.”
Can you replace a capacitor yourself?
Capacitors store an electrical charge and can hold it after the power is off. This is genuinely dangerous rather than cautious-sounding advice, and it is not a suitable homeowner job.
What will this cost?
A $139 diagnostic visit, waived when you book the repair.
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
What does a capacitor replacement cost?
It starts with a $139 diagnostic visit, waived when you book the repair.
Can I replace a capacitor myself?
We would strongly advise against it. Capacitors store an electrical charge and can hold it after the power is off.
My system hums but will not start. What is that?
That pattern commonly points at a capacitor, though a seized motor or a contactor problem can present similarly. It needs checking at the equipment.
Does a failed component mean I need a new system?
Usually not. These are ordinary repairs. If we think replacement is genuinely the better route we will explain why rather than implying it.
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.