An AC almost never quits without warning. It gives you signs first, sometimes for weeks. Catch them early and you're looking at a repair, not a dead system on a 110-degree day.
These are the four to watch for, what usually causes each one, and when to shut the system off.
The four warning signs
1. The air is warm, or barely moving
You hold your hand to the vent and the air is lukewarm. Or the flow is weaker than it used to be. Either way, something in the system is off.
- Low refrigerant from a leak in the lines. Refrigerant carries the heat out of your house, so when it runs low the system can't cool.
- A failing compressor, the part in the outdoor unit that moves the refrigerant around. If it fails, cooling never starts.
- A badly clogged air filter. It chokes the airflow, and left alone it can freeze the indoor coil.
The filter is an easy fix you can do today. The other two need a tech to find the real cause.
2. New noises or bad smells
A healthy AC makes a low, steady hum. New sounds are the system telling you a part is in trouble.
- Grinding or squealing often means worn motor bearings. A squeal can also be a worn belt.
- Banging or clanking can mean a loose part inside the compressor, or a compressor that needs to be replaced.
- Constant clicking points to an electrical problem, like a failing thermostat or a bad control.
Smells matter too. A musty smell during monsoon season can mean moisture is building up in the ducts or the unit.
A burning smell is the serious one. It can mean an overheated motor or a wiring problem. Turn the system off at the thermostat and book an HVAC repair visit.
3. The power bill spikes
Summer bills always go up here. A sudden jump when nothing about how you live has changed is a different story.
A failing part makes the system run harder and longer to hold the same temperature. You pay for all that extra run time. Fixing the part brings your comfort back and usually brings the bill back down.
4. Water or leaks around the unit
A little condensation is normal. Water pooling around the indoor or outdoor unit is not, and it can damage your home if you leave it.
The most common cause is a blocked drain line. That line carries the water the AC pulls out of your air. Dust from a haboob or a buildup of algae can clog it until the water backs up and spills over.
If the liquid is oily and has a chemical smell, it may be refrigerant instead. That is a bigger problem and needs a pro to handle it.
What to do when you spot one
- Smell burning? Turn the system off first.
- Check the air filter and swap it if it's gray and packed with dust.
- Make a note of what you saw or heard, and when it started.
- Book a repair visit before the problem grows.
When we come out, we find the cause and walk you through your options. On an older system, that might mean a talk about replacing it. Either way, you decide.
If the answer is a new system, our cooling systems page covers the heat pumps and central air units we put in for Valley homes.
Common questions
Is some water near my AC normal?
A little condensation is normal. Water pooling around the indoor or outdoor unit is not. The most common cause is a clogged drain line.
What should I do if my AC smells like it's burning?
Turn the system off and call for a repair. A burning smell can mean an overheated motor or a wiring problem.
Can a dirty filter really stop my AC from cooling?
Yes. A badly clogged filter chokes the airflow, and it can freeze the indoor coil. Check it first, since it's the one fix you can do yourself.