3 Air Handler Problems That Can Cause Your AC To Lose Efficiency Suddenly

20 October 2016
 Categories: , Blog


The air handler portion of your central air conditioner sits inside your house usually as part of your furnace. The air handler contains a few parts that work in conjunction to push refrigerant through the system to provide the cooling needed for your indoor air. If your HVAC system suddenly loses efficiency, a part in the air handler could need repair or replacement.

Here are a few air handler problems that can cause your air conditioning system to lose efficiency suddenly. Call an air conditioning repair service for more information.

Broken Evaporator Coils

The liquid refrigerant enters into the evaporator coils, which are calibrated to exert a phase change that turns that liquid into a gas. The phase change causes the coils to become cold on the surface, and that provides the source for cooling the circulating air that's passing back into your home.

If the evaporator coils crack or break, the refrigerant can drip out and compromise the efficiency of the phase change and the cooling of the coils. You might not notice the leak initially because the air handler has a drip pan to collect the condensate that occurs during the phase change. The drip pan continually empties into a drain pipe, so you might not notice that there's refrigerant in with the water.

You can conduct a visual inspection of the coils, but even small cracks can allow the refrigerant to drip through. Call an air conditioning services company to check the coils, replace the coils if necessary, and to top off your levels of refrigerant so that you regain efficiency.

Broken Fan 

A motorized blower fan points at the evaporator coils. The fan blows circulating warm air across the coils and then pushes the cooled air back into your home to lower the temperature. If the fan breaks, there won't be any ambient air to become cold or to move out into your home.

You can stand near the air handler during operation and listen for the sound of the fan running. If you don't hear the fan, then you need to call out a service tech for repairs. The problem is likely the fan's motor so that part will need replacing before your air conditioner will work again.

Broken Expansion Valve

A rarer problem arises in a part located at the junction between the outside supply lines and the evaporator coils. The expansion valve controls the inflow of the liquid refrigerant into the coils to best facilitate the phase change. The valve also keeps the liquid from flowing backward if a problem were to occur.

If the valve fails, the liquid can enter the coils at the wrong speed – or not at all. Both of those conditions can severely interfere with the phase change process. If the defective valve allows the liquid refrigerant to flow backward, the liquid can keep going until it hits and damages your compressor. You will then have an expensive compressor replacement before your unit works properly. It's much easier, and cheaper, to have your HVAC tech check and replace the expansion valve. Contact a company like D & W Heating & Air Conditioning Inc. to learn more.