My Air Conditioner Is On, But Not Cooling. What Do I Do?

Presidential Heating & Air Conditioning

Gaithersburg HVAC Contractors

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DIY Troubleshooting When Your Air Conditioner Stops Working Right

Of all of the stresses faced by a homeowner, problems with the HVAC system rank near the top. When the AC stops working mid-summer, it can ruin your vacation, disrupt work schedules, and bust your budget. There are a few things you can try on your own and perhaps save yourself the expense of an AC repair.

What to Do If the AC Is Running But Not Cooling

Your AC suddenly is not cooling well. Everything seemed to be working just fine a while ago, but now it is blowing warm air, or not running at all. Here are a few DIY troubleshooting tips to try before you call for professional help.

1. Check your thermostat settings. Your thermostat settings may have been changed. If you live with people who like to fiddle with the settings, chances are someone accidentally or purposefully changed the settings. Make sure the thermostat is set to cool and the temperature is set at a comfortable level.

2. Install fresh air filters. Excessively dirty air filters can block adequate air flow and cause the coils to freeze up and unable to cool the air. To change the filters, turn the AC off. The filters will be located just inside the air return register and may be in the air handler component itself. Remove the register grille and remove the dirty filter. Replace it with a new one of the same size. Clean dust and grime from the register grille and latch it back in place.

Find the air handler unit which is located inside your home, typically in a utility room, closet, or attic. Open the cabinet door on the unit. Look for a filter. Some air handler units have no filters. Many do. Your unit may have a standard disposable filter that looks like the filters in the air return register. You can replace it with a new one of the same size. Some units have a permanent filter that needs to be removed and cleaned. If you have one of these, follow the printed instructions for cleaning it. Once it has dried, replace it before restarting the AC.

Remember to replace the air filters at least every three months. This easy maintenance item will help ensure maximum longevity of your AC.

3. Make sure the coils are not iced over. If the air filters were so dirty that they blocked adequate air flow, your coils may have frozen up. Open the cabinet to the air handler and look for ice. If you see ice, it needs to melt before the AC can operate properly. Turn on the power to the system, and turn on the fan, but leave the AC off for an hour. This will let the ice melt. Replace the air filters if you have not already done so. Turn the AC back on. If the AC is blowing cool air, you solved the problem.

4. Clean the condenser. Turn the AC off at the breaker. Make sure all power to all of the HVAC components is off. Then hose down your condenser, which is located outside. Hold the hose about four inches from the machine and use slow up and down strokes to clean off any debris. You should see brown dirty water coming out at the bottom of the machine. Keep the AC off for an hour. Turn the power back on. Set the thermostat at the ambient temperature, and then lower it in increments of four degrees each hour. If that return the house to a comfortable temperature, you probably resolved the problem.

5. Contact a professional HVAC technician. If your AC is still not cooling after taking the steps outlined above, you need to call a professional. Your system may be leaking refrigerant or need an AC repair that only a technician can resolve.

What to Do if the AC Is Not Running At All

Suddenly you notice the house is warm. You adjust the thermostat lower and nothing happens. The AC is not coming on at all. Try these simple DIY troubleshooting techniques before you call the AC repair technician.

1. Check all power sources. Make sure the circuit breaker did not trip. If your AC has a reset switch, use it. Make sure the thermostat setting is on “cool”.

2. Check the AC condensate overflow switch on the air handler. Some air handlers have a small safety float switch connected to the condensation drain pipe. This float switch will turn off the AC if the drainpipe becomes clogged and backs up with water. You should clear the condensation drain pipe or replace it. Over time, these become clogged with algae and dust. Your system may also have an electric condensate pump. If it is old, it should probably be replaced also. Replacing it may be easier than cleaning it out.

3. Check the capacitor and contactor in the compressor. If you hear clicking, humming, or buzzing in the compressor when you turn on the thermostat, you may have a faulty capacitor or contactor. Testing and replacing these parts is probably a job for an experienced electrician or HVAC technician, as it involves working with significant electrical voltage. These components are easy for a professional technician to replace.

4. Contact a professional HVAC technician. If none of these DIY techniques resolved the problem with your AC, it is time to call an expert.

Regular Service Will Help Avoid AC Outages

Try to avoid any mid-summer AC repair. The best way to do that is to have a maintenance agreement in place with a reputable HVAC contractor. You will pay an annual fee for inspection and service on your entire HVAC system at the beginning of the season. They will professionally clean the components, ensure they are operating efficiently, and make any minor AC repair before problems become major expenses. For example, if the belt in your air handler is beginning to show wear and tear, the technician can replace it before it breaks and causes your AC to stop working. Your filters and other parts can be replaced.

Call a professional HVAC contractor and schedule an appointment.