Heating & Cooling Combined Unit: Why isn’t my air conditioner cooling well?

When your central air conditioner is running and producing some cool air but not cooling down your home, check the air filter. A dirty air filter won’t allow air to flow through the evaporator in your air conditioner and the air vents in your home properly. Replace the air filter if it’s dirty.

If replacing the air filter doesn’t restore proper cooling, then check for blocked air flow through the condenser unit outside your home. The condenser coils cool down hot, compressed refrigerant before the refrigerant enters the evaporator. If condenser coils are blocked or clogged with dirt and debris, then the central AC won’t cool very well. Clear grass and vegetation from around the condenser. Have a service technician clean the condenser coils if they’re clogged with dirt and debris.

If these tips don’t help restore cooling capacity to your HVAC system, then low refrigerant charge, a faulty compressor or clogged evaporator could be preventing the central air conditioner from cooling properly.

heating & cooling combined unit

THESE REPAIRS MAY HELP SOLVE YOUR HEATING & COOLING COMBINED UNIT PROBLEM

Replace the air filter

Replace the air filter

Replacing your air conditioner’s air filter is an essential task that keeps the system cooling properly. A dirty air filter inhibits air flow through the evaporator heat exchanger inside your air conditioner. Air flow will also diminish through the air vents throughout your home when the air filter is dirty. Replace the air filter regularly. For many central AC systems, you’ll need to replace the air filter monthly.

To replace the air filter, shut off the air conditioner and allow the blower fan to stop if it’s running. Open the filter access door and pull the old air filter out. Position the new air filter according to the air flow arrow on the side of the filter and slide the new air filter into the filter housing. Close the filter access door. Turn the air conditioner back on to restore cooling.

Air filter

Find the required part specific to your product.

Clean the AC condenser coils

Clean the AC condenser coils

Blocked or dirty condenser coils can prevent your central air conditioner from cooling properly. Clear grass and vegetation from around the condenser to allow proper air flow through the coils.

Have a service technician thoroughly clean dirt and debris from the condenser coils if they’re clogged.

Clean the ac condenser coils

Find the required part specific to your product.

Symptoms common to all heating & cooling combined units

Choose a symptom to see related heating and air conditioning system repairs.

Dirty air filter, clogged condenser coils, low refrigerant charge, faulty compressor
Thermostat problem, clogged air filter, burner failure
Dirty flame sensor, failed flame sensor, damaged burner, bad high limit switch
Thermostat problems, bad compressor/condenser fan capacitor, lack of refrigerant, failed compressor
Main causes: errant thermostat settings, lack of electrical power, clogged drain line, wiring failure, control failure.
Main causes: Errant thermostat settings, lack of power, bad interlock switches, lack of exhaust ventilation, wiring failures.

Repair guides common to all heating & cooling combined units

These step-by-step repair guides will help you safely fix what’s broken on your HVAC system.

March 16, 2022
By Sears PartsDirect staff
How to unclog the air conditioner drain line

The condensate drain line for your central air conditioner can clog with mold and mildew. Water will back up and start dripping below the inside air conditioner unit. Follow the steps in this guide to unclog the drain pipe.

Repair difficulty
Time required
 15 minutes or less
March 16, 2022
By Sears PartsDirect staff
How to replace the furnace flame sensor

The flame sensor detects when furnace burner flames are lit. You may need to replace the flame sensor if flames only stay on for a few seconds.

Repair difficulty
Time required
 15 minutes or less
How to replace a heating and air conditioning system thermostat

The control thermostat for your HVAC system can stop working. This repair guide shows how to replace it.

Repair difficulty
Time required
 30 minutes or less

Articles and videos common to all heating & cooling combined units

Use the advice and tips in these articles and videos to get the most out of your HVAC system.

February 22, 2022

Why is my furnace not igniting?

By Lyle Weischwill

Find out why the burner on your furnace isn't igniting.

February 22, 2022

Can a furnace be repaired?

By Lyle Weischwill

Learn about furnace repairs and how much they cost.

February 23, 2016

What to check if your air conditioner isn't cooling video

By Sears PartsDirect staff

If your central air conditioner isn't cooling as it should, we'll show you how to check for a tripped float switch and clogs in the drain pipe.