How to Troubleshoot Your AC Unit Before Calling an AC Repair Company in Arnold

What’s the First Thing to Check When the AC Stops Working?

The first thing to check when your AC stops working is the thermostat.

Before assuming there’s a major issue, make sure your thermostat is set to “cool” and that the temperature is set lower than the current room temperature. Sometimes, settings can be accidentally changed, or the batteries in a battery-operated thermostat may be dead.

If the thermostat seems fine, the next quick check is your circuit breaker. A tripped breaker can shut down your AC unit, especially if there was a recent power surge. If the breaker is off, reset it and see if your AC kicks back on.

How Else Can You Troubleshoot Your AC Unit?

If your thermostat is set correctly and your circuit breaker isn’t tripped, but your AC still won’t work, don’t worry—there are a few more things to check before calling for repairs. Follow these troubleshooting steps to see if you can get your system running again.

Check the Air Filter

A dirty or clogged air filter can restrict airflow, causing your AC to work inefficiently or even shut down. Locate your air filter (usually in the return vent or inside the air handler), and if it’s covered in dust and debris, replace it with a clean one. For best performance, filters should be changed every 1–3 months.

Inspect the Outdoor Unit

Head outside and take a look at your condenser unit (the big metal box outside your home). If it’s covered in leaves, dirt, or other debris, it may not be able to properly release heat, which can cause your AC to stop cooling. Gently clear away any obstructions and hose down the coils to remove dirt buildup.

Check the AC Fuses

If your AC isn’t turning on, the problem could be a blown fuse in the disconnect box near the outdoor condenser unit. These fuses help protect your system from power surges and can wear out over time.

How do you tell if your AC fuses are blown? Follow these steps:

1. Turn Off the Power: For safety, switch off your AC at the thermostat and shut off power to the outdoor unit at the breaker panel.
2. Open the Disconnect Box: This box is usually mounted on an exterior wall near the condenser unit. Inside, you’ll find fuses that look like small cylinders or glass tubes.
3. Test the Fuses: You can check if a fuse is blown using a multimeter. Set it to the continuity or resistance (ohms) setting and touch the probes to each end of the fuse. If the meter reads “0” or beeps, the fuse is good. If there’s no reading or the meter stays at “1” (or OL), the fuse is blown and needs to be replaced.

If you suspect a blown fuse but don’t have a multimeter, you can also replace both fuses with new ones of the same type and rating to see if that fixes the issue. However, if the new fuses blow again right away, this indicates a deeper electrical problem that requires professional repair.

If you’re unsure about checking or replacing the fuses yourself, Grove Heating & Cooling is here to help! Our technicians in Arnold can safely diagnose and fix any electrical issues with your AC system. Give us a call to schedule a service appointment.

Look for Frozen Evaporator Coils

If your AC has been running but isn’t blowing cold air, check for ice buildup on the indoor evaporator coil (located inside the air handler). A frozen coil can be caused by restricted airflow or a refrigerant issue. If you see ice, turn off the AC and let it thaw completely before turning it back on. If it freezes up again, you need to call us for AC repair so we can find and fix the underlying issue.

Make Sure Vents Are Open and Unblocked

Blocked or closed air vents can create airflow problems, making it seem like your AC isn’t working properly. Walk through your home and ensure all supply and return vents are open and free of obstructions like furniture, rugs, or curtains.

Check the AC Drain Line

Your air conditioner removes humidity from the air, and the condensation drains through a small pipe (the AC drain line). If this line becomes clogged with algae or debris, it can trigger a safety switch that shuts off your AC.

To check and clear the drain line, follow these steps:

1. Locate the Drain Line: The drain line is usually a PVC pipe near the indoor air handler, often leading to a floor drain, utility sink, or outside your home.
2. Check for Standing Water: If you notice water pooling around the air handler or near the drain pipe, it’s a sign of a clog.
3. Flush the Drain Line: Try these methods to clear the clog:
   • Use a Wet/Dry Vacuum: Attach the vacuum hose to the end of the drain line (outside your home) and create a tight seal using a rag or duct tape. Turn on the vacuum for 1–2 minutes to suck out any debris.
   • Use Vinegar or Bleach: If the line isn’t fully blocked, pour a mixture of one cup of white vinegar or a diluted bleach solution (1:1 bleach to water) into the drain pipe through the access port near the air handler. Let it sit for about 30 minutes before flushing it with warm water.
   • Use a Drain Cleaning Brush: If your drain line has a visible blockage near the opening, gently insert a thin, flexible brush (such as a pipe cleaner or a drain cleaning brush) to loosen debris.
4. Test the Drainage: Once you’ve cleared the clog, pour a small amount of water into the drain line’s access port. If it drains freely, the line is clear. If water backs up, repeat the process.

Test the AC Again

After going through these troubleshooting steps, try turning your AC back on. If it starts working again, great! If not, there could be a deeper issue that requires a professional technician.

What If Troubleshooting the AC Unit Doesn’t Fix the Problem?

Troubleshooting your AC can often save you time and money by resolving simple issues like thermostat settings, clogged filters, or blocked drain lines. But if you’ve gone through these steps and your air conditioner still isn’t working, it’s time to call in the professionals.

Continuing to run a malfunctioning system can cause more damage, so the best thing to do is turn off your AC and contact Grove Heating & Cooling. Our expert technicians in Arnold are ready to diagnose and repair the issue, so your home stays cool and comfortable. Give us a call today for AC repair in Arnold, MD!