
AC Blowing Warm Air? 7 Checks to Try Before You Call
You walk in thinking it’ll be cool, but the whole house is like an oven, with warm air blowing from the vents. Irritation peaks. While it is incredibly easy to imagine a fried compressor and a massive repair bill, hold on. The actual culprit might be laughably minor. Before paying an expert, scanning a few quick items is totally worth your time (and keeps your wallet safe).
Check Your Thermostat Settings First
A rogue finger can ruin everything. Your very first action should involve checking the wall unit. A busy child may accidentally press buttons, completely disrupting the setup. You can confirm your device is performing its true intended function by knocking out these three incredibly basic, fast steps:
- Find the central system control switch and verify it remains locked into the cooling mode instead of the heating mode.
- View the desired temperature digit on the main screen, ensuring without doubt it sits lower than the room temperature.
- Check the internal fan option and switch it directly from the “On” selection to the “Auto” selection.
Whenever that fan stays left on “On,” the main indoor blower motor runs endlessly, pushing warm room-temperature breezes everywhere. You really must always pick the “Auto” setting. This guarantees the machine only ever pushes air when those crisp, chilly winds are completely generated, perfectly cooled and ready to flow right now.
Inspect Your Dirty Air Filter
We love our dogs and cats, but they shed a lot of hair inside the house. Your air conditioner needs to pull in warm air from your rooms to cool it down. The indoor air filter traps that pet hair and dust so those messy things do not get inside the delicate machinery. Over time, the air filter gets covered in a thick layer of dirt. When the filter is completely blocked, the air cannot flow through the system properly. This lack of smooth airflow can cause your system to start blowing warm air. You should pull the filter out of its slot and hold it up to a bright light bulb. If you cannot see light shining through the material, you must slide a brand new filter in.
Inspect the Outdoor Condenser Unit
Your air conditioning system has a large metal box sitting in your yard. This outdoor machine is called the condenser and its main job is to release the heat that was taken out of your house. The condenser needs plenty of empty space around it to push the hot air away into the open sky. Sometimes tall grass, garden weeds and fallen tree leaves grow too close to the metal box. When natural debris blocks the metal sides, the heat gets trapped inside the machine. This makes the whole cooling system work too hard and blow warm air.
- Pull away any thick vines growing on the metal grates.
- Rake up dry leaves resting against the bottom of the machine.
- Trim your bushes so there is open space all around the box.
Check Your Circuit Breaker Box
Your cooling system uses a lot of electricity to run the different heavy motors. The indoor blowing fan and the outdoor condenser machine are usually connected to two separate electrical switches in your main breaker box. Sometimes a sudden power surge during a summer storm can cause the outdoor switch to trip off for safety. If this happens, your indoor fan will keep blowing air, but the outdoor cooling unit will not turn on at all. You should find your electrical panel and look for any switches that have moved to the middle resting position. Push the switch all the way off and then snap it firmly back to the on position.
Look for a Frozen Evaporator Coil
It sounds crazy to find ice during the hottest days of summer, but it happens quite often. Inside your indoor air conditioner unit, there is a very cold metal part called the evaporator coil. This coil removes the heat from the air as it passes through the system. Sometimes the coil gets way too cold and literally freezes solid with a thick block of white ice. If there is a big block of ice inside your machine, the cold air cannot travel past it and into your home. A frozen coil is often caused by a dirty air filter stopping the air. If you see ice on the indoor unit, you must turn the air conditioner off completely. Let the thick ice melt before you start the system again.
Make Sure Your Vents Are Open and Clean
Rearranging your space is fun, but carefully consider exactly where that bulky sofa lands. Cold air navigates a labyrinth of hidden tubes, eventually escaping into your rooms through metal grates. As heavy drapes or plush rugs slide blindly over these spots, they often block and choke the draft entirely. So you really must walk through every room (yes, even the basement) to audit the house airflow. Ensure each lever on the steel vent cover is set to open. This lets you enjoy cooling all summer with no trouble.
- Relocate any heavy couches or large armchairs that are currently placed directly over your essential floor registers.
- Quickly gather up stray toys and scattered blankets obstructing the cold air.
Check for Signs of a Refrigerant Leak
Refrigerant is the special chemical compound inside the copper pipes that makes the cooling magic happen. Your air conditioner needs an exact amount of this fluid to work perfectly. If there is a tiny hole in the metal pipes, the chemical will slowly leak out into the outside air. When the system runs low on refrigerant, it cannot absorb heat from your house, so it will just blow warm air at you. You might hear a strange hissing noise coming from the pipes if a leak is present. You might also notice weird ice building up on the copper lines.
When to Call Dremus Appliance Repair for Help
You can solve many simple airflow problems on your own by changing a dirty filter or flipping an electrical switch. However, there are some complex mechanical issues that require a highly trained professional to fix safely. If you have tried all the simple checks on this list and your house is still hot, it is time to ask for expert help. You should never try to fix broken electrical wires or leaking chemical pipes by yourself because it is very dangerous. The friendly technicians at Dremus Appliance Repair have the right tools and knowledge to find the exact problem quickly. You can trust Dremus Appliance Repair to fix your air conditioner properly so your family can stay comfortable.
FAQs
What should sit around the outside AC box?
Nothing! Keep tall grass, vines and leaves away. The big metal box needs lots of open space to push heat away.
Can a power storm stop the AC?
Yes. A storm can flip a switch in the main breaker box. Find the box and push the switch firmly back on.
Why is there ice on the indoor AC?
A dirty filter can freeze the inside parts. The thick ice blocks the cold air. Turn the system off and let the ice melt.



