6 Signs Your Air Conditioner Needs Service

You may see several symptoms when an air conditioning system is in trouble. Here are six signs of air conditioning trouble and advice on how to handle air conditioning problems.

1. System Fan Works but Nothing Else Does

If your central air conditioning stops working altogether, turn the controls to the fan-only position. If the fan doesn't work, check your breaker box for a blown fuse.

If your fan works, that's a good sign that power is getting to the heating, cooling, and ventilation (HVAC) system. However, the fan alone can't cool the house.

Your cooling system may not be working, even when the fan works, due to:

 • Compressor problem
 • Automatic shutoff due to a drain issue
 • Internal switch problem
 • Loose wiring

Modern HVAC systems have many parts that break down over time. When only your fan is working on your HVAC system, call in experts to inspect your air conditioning components. A small adjustment or repair may be all that's needed to get your air conditioning back on track.

2. No Response to the Thermostat

Do you change the thermostat settings, but nothing happens? If your air conditioning continues to run even when you raise the thermostat settings, check to ensure that the thermostat is set to the automatic mode. If the thermostat is set to the on mode, the thermostat will not shut off unless you turn the entire unit to the off or auto setting.

If your air conditioning unit won't click on after lowering a modern thermostat, check to ensure the batteries are fresh in the thermostat itself. Older thermostats don't have batteries, but they do have sensors that can wear out and fail to send a signal to the main HVAC unit. A failed sensor may cause your unit to continue cycling rapidly no matter how you set the thermostat.

3. Air Conditioning Is Too Cold

If your thermostat is located in a sunny or warm part of a wall, it can send false readings to your HVAC system. The thermostat is registering the temperature as much higher than it is, so the air conditioning cycles too often.

If a thermostat is located in an overly warm room where people don't normally spend time, the air conditioning may be too cold in the rooms where people do congregate. If the air conditioning is running full blast to cool upstairs rooms, the downstairs rooms may have more of a chill than desirable.

Your HVAC repair professionals can move your thermostat to a more suitable location out of the sun and not close to any ovens, clothes dryers, or warm electronic devices. HVAC experts can also install an attic fan to pull cool air upstairs and circulate it throughout the warmer upper floors.

4. Condenser Coils Keep Freezing

If your air conditioning is running, but only warm air is coming out, you may decide to investigate the guts of your central HVAC system. Call in the experts before you remove the panel on your main unit.

If you do remove the panel, you might notice that the copper coils inside the evaporator are covered in ice. If so, your air conditioning system has a problem.

The coils become ice-covered when the refrigerant temperature in the air conditioning lines falls below 32 degrees Fahrenheit — the freezing point of water. The frozen refrigerant causes humidity on the coils to freeze and coat the surface of the copper.

Coils may freeze due to:

 • AC units running continuously
 • Dirty filters
 • Clogged cooling fins
 • Inadequate system ventilation
 • Blown fuse

In some cases, frozen coils are the result of low refrigerant levels in the system. Regardless of the cause of coil freeze-ups, have your system checked out by professionals if it continues occurring.

5. Screeches or High-Pitched Noises

When you hear a whistling or high-pitched sound while your air conditioning is running, you may have a lack of return air. Your air conditioning system needs fresh air to keep functioning properly, so any return-air issues need to be solved right away.

Check the grill over your return air duct and clear away excess dust and debris buildup. An object may be blocking the return air vent, or your air filter may be clogged. Correct these issues.

A screeching sound may come from a loose fan belt or a worn motor. If a new filter and clean up don't solve the noise issue, call your air conditioning repair service for a full inspection of your system.

6. Thumps and Rattles

Some crinkling and banging are normal in an HVAC system. If your ductwork is damaged, undersized, or weak, you may hear strange sounds including thumps and rattles. Undersized ductwork increases wear on your system, so have it replaced with ductwork that's the proper diameter for your HVAC system.

Humming and scraping sounds may indicate worn components in your air conditioning system. Your fan, switches, wiring, and mechanical parts may need tightening up or replacement.

Contact the HVAC experts at Henry's Service All to schedule an inspection of your air conditioning system problem . We repair, adjust, and replace air conditioning systems throughout the Greater Irving and Dallas-Ft.Worth, Texas, areas.