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Why is Your AC Blowing Hot Air

Why is Your AC Blowing Hot Air

Need Air Conditioning Repair? | AC Blowing Warm Air

We have come to depend upon our air conditioning to keep us comfortable during the summer. Unfortunately, finding the AC blowing warm air is a common occurrence, especially on aging units. There are several potential causes for AC blowing warm air. Before you call a technician there are a few things you can check and perhaps restore cooling.

Thermostat Settings

First, check your thermostat and ensure the fan is on “automatic” rather than “run”. Most of us at some time or another switch the fan to “run” to pull fresh air in an open window to air the house out or pull cool outside air in. For whatever reason, people do cut the AC to “off” and the fan to “run”. If it’s set to run, switch it back to “auto”. Then check the thermostat to ensure it is on “AC” or “Cooling” and not set to “off”.

Next check the temperature the thermostat is set on. If it is on 80 and the temperature in the house is 79 or lower the compressor will not kick on to cool, and if the fan is on “run”, you will be experiencing the AC blowing warm air. If you have a programmable thermostat and have experienced even a brief power outage, the settings may have reverted to the factory default and may require you to reset them to your desired temperature.

The second thing to check is the unit’s breaker in the homes electrical service box. It should be in the “on” position. If it is not, push it back to the on position, and lower the thermostat if the unit does not automatically come on. If this doesn’t correct the problem you will continue to experience the AC blowing warm air.

The third thing to check is the filter. An excessively dirty filter can cause the ac to improperly cool and potentially overheat and damage the compressor. If the filter is dirty change it. Unless your unit’s manufacturer, or the filters manufacturer specifies differently change your filters each month. If you have filters that require less frequent changes continue to check them once per month.

Next, check the inside cooling lines, if any, within the home. If your system is a split system the lines will be located in the air return (the panel where you change the filter). With the panel removed look at the copper lines, if they are frosted or iced over your unit is low on coolant due to a leak. This will require your HVAC technician to provide repairs and recharge the system with coolant. Until this is done you will continue to experience the AC blowing warm air only.

Visually check for water overflowing the condensate pan, there may be water in the bottom of the unit, look with a flashlight but do not touch any wires due to the risk of shock. You may note water leaking out onto the floor. If this is occurring water may have shorted a circuit out and caused it to throw a breaker either in the unit or in your homes electrical service panel.

The cause of water leakage is generally a stopped up condensate drain. The condensate drain will lead to an outside source on the lawn. If no water drainage is evident this may further point to a stopped up condensate drain. The condensate drain attaches to the condensate pan which catches the water caused by the “sweating” of the coils in the cooling process. Another potential cause of excess water is the coils are in need of a good professional cleaning.

Some units have breakers on the inside of the air return. If yours has one and leaking water is not the potential problem check to see if it is in the “on” position. If not, press it to on. Other units will have a reset switch on the outside of the home somewhere near the exterior portion of your unit. There is generally a box with a reset switch near the unit on the wall or under an accessible deck. Either of these being tripped to “off” can be the cause of the AC blowing warm air.

If the unit is not running at all outside, and the breaker is “on” in the electrical service panel, visually inspect any wires you see leading from the unit to under the house. Do not handle them, if there is a break in the wire you could receive a serious shock that is potentially fatal. If you note damage to any insulation of the wires, or visible wires themselves a small animal may have chewed a wire through. This will require the services of a certified technician to repair.

Thrown breakers occasionally occur and can be related to problems in the electrical grid or other. If your unit is experiencing thrown breakers frequently it should be checked out to ensure the safety of the wiring involving the unit by a trained technician. Besides being an annoyance causing the AC to be blowing warm air, it is a potential hazard that could place you, your family and your home at risk.

There are many other possible causes of an AC blowing warm air and these will require the services of your technician to repair.

Cypress Heating and Air Conditioning will be happy to assist you when your AC is blowing warm air. We provide emergency service 24 hours a day, 7 days a week for your convenience.