Why is my AC running but not cooling?

hvac system outside while the sprinklers run

How do you know if your air conditioner is cooling?

By the calendar, we’re still in Spring, but by the thermostat, for many of us, it is feeling like summer already. If you haven’t already had to have a home air conditioner repair call, now is the time to have an air conditioner repair service. Having your system checked now before summer is a preventive maintenance for any homeowner. It could be the difference between having an air conditioner repair or replaced done.

Another scorching summer will be here any day, so make sure your air conditioner or conditioning is ready so that you don’t have to have an expensive home air conditioner repair bill, or worse, a new unit. The following is a checklist that will tell if your home and HVAC is ready to do its thing:

  • The air filters. You follow proper homeowner maintenance and have either changed or cleaned the air filter in the last 30 days.  
  • The thermostat is powered. As a responsible homeowner, you have recently changed the batteries in the thermostat, or you performed the manufacturer’s suggested maintenance test. You have the thermostat is in the “on” and “cool” position.
  • You can hear the blower fan. You can hear the blower fan whirring with no issues of binding up.
  • The inside temperature is cooler than outside. You turned the AC on for a day and came home to a cool house.
  • The air conditioning unit is quiet. All you can hear is the normal blower fan whirring sound from the inside and outside components.
  • There is adequate insulation. During your recent HVAC system maintenance check-up, either you or an experienced HVAC technician have checked the insulation in the attic and it is ready for another scorching summer that will let the air conditioner cool without overworking.
  • You can minimize excessive sunlight. You have blinds and curtains on every window so you can minimize the blistering sun every day.
  • All debris is cleared of the outside component. The outside component is free of debris, grass clippings, leaves, sticks, etc., including critter nests.

How do you troubleshoot an outside AC unit?

Good thing you checked it out and make sure the air conditioner is ready for summer, because the outside component is quiet, and the house isn’t cooling down. There are two things that professional HVAC technicians find during home air conditioner repair service calls:

  1. The outside component of the AC is humming, but the fan isn’t spinning.
  2. There is warm air blowing through the vents inside the house even though you have checked everything from the air filter to the thermostat.

Here are some typical reasons that home air conditioner repair technicians find to be the problem:

  • BAD CAPACITORS: Energy is stored in capacitors that power the fan inside that outside component of your HVAC system. A capacitor starts the fan and keeps it running, and some HVAC systems have dual capacitors that power the fans and the compressor. A capacitor is like a battery and over time, loses its ability to store energy. High temperatures, high voltage, and power surges can blow a capacitor out. When the capacitor is out, the fan won’t turn. A fan may not turn if there is debris wrapped around the fan, the fan motor bearings are dirty or jammed, or it damages fan motor. 
  • DEFICIENT POWER SUPPLY: If the fan isn’t getting adequate power supply, it will stop working. This is typically not an easy diagnosis to make and requires the experience and skills of a professional HVAC technician and home air conditioner repair call. 
  • THE CONTACTOR: The fan motor is controlled by the contractor and when it goes out, the fan will stop. This isn’t a DIY project and requires a professional home air conditioner repair technician. 
  • BURNT OUT FAN MOTOR: Fan motors will burn out simply from wear and tear, or from poor maintenance. With proper homeowner maintenance steps, you can avoid making those unexpected and expensive home air conditioner repair service calls.

What causes outside AC unit to stop working?

Even the best, most expensive, and best-maintained HVAC system will go out at some point. Some of the most common problems found during a home air conditioner repair service call are: 

The Wiring

There are numerous networks of wires connecting parts of your HVAC system.  Sometime there are above ground wires exposed and sometimes, the home air conditioner repair technician will find broken, damaged, or eroded wires behind the walls.

An Icy Build Up

When the air filter hasn’t been changed or cleaned, ice will build up about the evaporator coils, pipes, even outside the unit because the system must work twice as hard and the internal parts freeze up. When you see ice built up, you need to call for a home air conditioner repair because that ice will need to be removed from some delicate parts of the internal structure that can be damaged if you don’t know what you’re doing.

A Faulty Thermostat

Homes outfitted with an analog thermostat will find that this old style thermostat cannot keep up with today’s high efficiency HVAC models.  Replacing the unit with a digital thermostat that has a touch screen is less likely to give you any problems as the thermostat will communicate with the system. A homeowner can usually do this themselves or you can place a home air conditioner repair service call and have an experienced technician install a new thermostat.

The Refrigerant

Your HVAC system has refrigerant running through tubes in a closed circuit. Sometimes, a central air system will accumulate leak and the refrigerant drips out. This can often be repaired by a home air conditioner repair service call, but more than once, you probably need to replace the unit.

The Condenser, Evaporator Coils, and Filter

As the homeowner, you should be changing or cleaning the air filter monthly. What you can’t do is clean the condenser or evaporator coils. A professional to clean those during a home air conditioner repair service call.

A Faulty Compressor

The compressor pumps compressed the refrigerant through the coils and throughout the air conditioner system to cool the air. When the compressor goes out, the amperage rises to meet the thermostat demands. With a home air conditioner repair service call, the technician will replace the condenser and restore your home with cooled air.

A Faulty Motor

When a blower motors is running at half speed or has frozen up, it stresses the central air system. This required the motor to be replaced during a home air conditioner repair service call.

How do I reset my air conditioning unit?

If you have tried to turn on your air conditioner already but didn’t feel cool air, it could be the thermostat that needs to be reset. A thermostat should be reliable, but like anything, they get old and wear out. The following steps will help you reset your thermostat.

  • Turn the AC off at the Thermostat by turning it to the “off” position.
  • Find the Breaker Box and flip the breaker marked “AC” to the off position.
  • Wait 30 Seconds to 1 minute then flip it back to the on position.
  • Next, turn the thermostat back to “on” and make sure it is in the AC mode.

This should get your AC going again with cool air. If it didn’t then you must make a home air conditioner repair service appointment with a certified technician.

HVAC systems exterior, not functioning

How do I fix my AC?

Most air conditioning problems will need a professional home air conditioner repair service, there are some things you can do yourself using the following guidelines:

  1. The Air Conditioner Doesn’t Turn On: If the air conditioner doesn’t turn on, check the outside component is running, the unit is plugged in, and the thermostat is set on AC and ON.
  2. The Air Conditioner Is Not Cooling: If the air conditioner is on, and the thermostat is set correctly but it still isn’t cooling, the condenser could be blocked or dirty. Check that the outside component doesn’t have any debris, grass, or weeds around it that could block the air circulation. Check the filter to see if it needs cleaning or replacing.
  3. The Air Conditioner Isn’t Cooling Adequately: If the air conditioner is on and set correctly, but still isn’t cooling to the comfort you desire, the evaporator coil could be frozen, or your system may be too small. If there is ice inside the exterior component, turn the system off and schedule a home air conditioner repair service. If you keep trying to run it while frozen, you could do more damage and the air conditioner repair cost will be more than you want to pay. 

This time of year, knowing that summer is about to arrive, make sure your air conditioning unit is running and ready to go. Every day you wait, the professional air conditioning technicians are getting booked further out.  Get started on your home air conditioner repair needs when you call the experts from Advanced Plumbing Heating & Air at 707-229-0482!