Our experts show you easy solutions for the most common central air conditioning repairs. You’ll be up and running sooner and will save the expense of a service call. We talked to local HVAC repair technicians to get their AC fan repair and maintenance tips. These tips will help you with the most common “low cooling” and “no cooling” problems. You’ll need an inexpensive multimeter, a voltage sniffer, an assortment of insulated screwdrivers, and a socket set.
Why is My Air Conditioner Not Cooling the House?
- Make Sure the Problem Isn’t the Furnace
Set your thermostat to AC mode and lower the temperature setting. If the furnace fan kicks in, the problem isn’t in the furnace. If the fan doesn’t run, try resetting the furnace circuit breaker. If the fan still won’t start, call a pro — the fixes shown here won’t work.
Next, check the outside condensing unit. The compressor (which sounds like a refrigerator) and fan should be running. If not, follow the troubleshooting and repair procedures shown here.
- Caution: Turn Off the Power
Turn off the A/C and furnace breakers in the main electrical panel before pulling the outdoor disconnect or removing the condensing unit’s access panel. Then use a voltage tester on the wires coming into the contactor to make sure the power is really off.
- AC Doesn’t Work? Buy Parts
The AC contactor (relay) and start/run capacitor(s) (see illustration below) fail most often and are inexpensive. So it’s a safe bet to buy and install those parts right away, especially if your air conditioning service unit is older than five years. If these AC Repair doesn’t work, at least you’ve covered the most common failures, and your service guy can concentrate on finding the more elusive problem.
Central air conditioners are made up of two separate components: the condenser unit, located outside the house on a concrete slab, and the evaporator coil above the furnace. Both the evaporator and the condenser are sealed. Therefore, a professional service person should be called for almost any maintenance other than routine cleaning. Central air conditioners should be professionally inspected and adjusted before the beginning of every cooling season. However, don’t let your maintenance end with this annual checkup. While there aren’t many repairs you can make yourself, there are specific maintenance procedures you can follow to keep your system operating at peak efficiency.
Caution: Before doing any work on an air conditioning system, make sure the power to the system, both to the condenser and to the evaporator assembly, is turned off.
How To Repair Room Air Conditioners:
Cooling units that you mount in your window have the same job as central air conditioners, but the repair principles are different. Follow these instructions to get your unit running smoothly.
- Major Appliance Repair: If the a/c isn’t the only thing in your house on the fritz, you can learn how to fix other machines in this article.
- Small Appliance Repair: Once you’ve tackled the a/c, a toaster or blender seems like child’s play. Find out how to fix them here.
- Thermostat Maintenance: To make sure there’s actually a problem with your a/c, you may want to check the thermostat, too. Learn how to calibrate a thermostat.
Central air conditions will need some professional maintenance, but there are many minor problems that you can easily fix yourself. If your central a/c unit isn’t working properly, look for the problem you’re experiencing on this chart and see if it’s a do-it-yourself job.
Cleaning the Evaporator
The evaporator for the central air system is located directly above the furnace in the plenum. The evaporator may not be accessible, but if it is, you should clean it once a year. If the plenum has foil-wrapped insulation at its front, you can clean the evaporator; if the plenum is a sealed sheet metal box, do not attempt to open it. Here’s how to clean an accessible evaporator:
During the fall and winter, outside condenser units should be protected from the elements to prevent leaf blockage and ice damage. Cover the condenser unit with a commercial condenser cover made to fit the shape of the unit or use heavy plastic sheeting secured with a sturdy cord. If you’ve cleaned everything you can and you’re still not getting cool air, the problem could be the refrigerant.
Handling the Refrigerant
The coolant used in most air conditioning systems is a refrigerant called Freon. If the system does not contain the proper amount of Freon, little or no cooling will take place. If you suspect a Freon problem, call a professional service person to recharge the system.
Cooling units that you mount in your window have the same job as central air conditioners, but the repair principles are different. Follow these instructions to get your AC Installation smoothly. You’ve likely been running your air conditioner all summer, and if problems have developed, you might not have been able to treat them the right way. But with summer officially over and fall here, now is the time to get your air conditioner checked for problems and repaired if issues have arisen. It gives you the maximum amount of time to treat the issue and ensures that your air conditioner will be ready to go as soon as you need it in the spring.
Ideally, you should schedule a maintenance session with a qualified air conditioning technician to check your system for any problems that may have developed over the summer. It’s a kind of tune-up for your AC and allows the technician to correct little problems like loose bolts as well as check for bigger ones that might require formal repair service. That’s an easy and efficient way to make sure your system gets the attention it needs.
Looking For Signs Yourself
If you’re not able to schedule maintenance, or a technician serviced the system at the beginning of the summer and you don’t feel a second session is merited, you can still check your AC for signs of any unusual activity. Our trained professionals should examine the interior of the system. Air conditioners contain potentially dangerous components like refrigerants, and only professionals can properly determine the cause of any issue.
That doesn’t mean you can’t notice when something is wrong, however. Anything that doesn’t match your air conditioner’s regular functioning should be cause for concern. More specifically, look for the following common signs of a problem.
- Strange noises: These include anything you don’t recognize as part of your system’s normal noises: bumps, grinds, hum, whistles or clangs. In most cases, the strange noise will start and stop when you turn your air conditioner off and on.
- Reduced cooling levels: If you turn the system on and only warm air comes out, you can probably deduce the need for repairs. But it doesn’t need to be that overt. Sometimes, it can be as simple as cool air coming out of the vents that don’t feel quite as cool as it normally does.
- Low airflow: If the air doesn’t emerge from the vents as swiftly as it normally does, there might be a blockage or a breach in the ducts. It can also be caused by problems with the fan or fan motor, all of which require a service technician’s attention.
- Higher bills: In some cases, the problem doesn’t manifest with anything overt, but components in need of repair or replacement will reduce your system’s efficiency: driving your monthly bills up. If you found yourself paying more for air conditioning on a monthly basis this summer, even if you didn’t use the system more than normal, it might be time for a repair call.