Last updated on March 10th, 2024 at 03:01 pm

Whether you have a Fedders, GE, Haier, Frigidaire or another Air Conditioner, the number one complaint so far this HOT summer season is why won’t my air conditioner work? It just seems to blow hot air…or doesn’t seem to cool very long at all.

Unfortunately there are a lot of different reasons for this. Some of them are easy to understand and fix. Others, well, they aren’t so much.

Filters. Air conditioners work on the heat exchange through air train of thought. Namely, they force air into a compressor, the air is cooled and sent into the room. The heat “exchanged” is forced outside through the coils. This is a gross oversimplification of a complicated idea, and obviously the number one, most important component is the compressor. But since it is dependent on air coming from the warm room you are trying to cool, the only thing that stands in the air’s way is a filter. Many window unit air conditioners use a washable filter that MUST be cleaned in order for the unit to operate at peak efficiency. In some cases, a dirty or incorrectly installed air filter can cause a unit to fail, malfunction, or not turn on at all. It may also prevent the compressor from working.

Central Air units use the normal filter in the furnace return air system, so it is important to keep the filters replaced every 30-60 days, or as recommended by the manufacturer of both the filter and air conditioner unit

Compressor & coils. For the most part, when the compressor goes, the A/C unit is useless. That doesn’t help you though, does it? If you checked the filter, the next step is to check to make sure the compressor works. IF your unit has a thermostat, make sure the desired temperature is actually below the room temperature by at least 3-5 degrees. (Many units will run with the fan on in an attempt to save energy by cooling with just the fan.) Wait at least one minute, as turning on the compressor too quickly can cause damage – especially for central air units. If the compressor still doesn’t turn on, double check by plugging in a small CFL lamp into the same set of outlets as the AC. When the compressor kicks in, there is usually a small power surge associated with the home’s electrical system delivering more power to the AC compressor, which causes a very brief flicker. IF you see the flicker, the compressor turned on. If not…

Clean the coils. Sometimes a dirty coils can cause blockage. Check for water at the base of the unit too.  Empty standing water and try cleaning the unit. If that doesn’t work…

Check the inline fuse. Some units have filters (electrical filters) and inline fuses within access around the removable filter. Unplug the unit and check if this is blown. If the fuse looks good, and you’re still baffled…

Check the thermostat for damage. It looks like a little silver probe again near the filter (usually). If it looks damaged, the system probably isn’t getting a good reading and thus can’t decide whether to turn on the compressor or not. If all that fails, and you’re still baffled, and are really hot and can’t decide what to do next…

Take a cool bath or go for a swim. Seriously. Leave the unit, come back to it later. If it still doesn’t work, your options are to call a repair service, return the unit, or buy a new one. They don’t last forever, especially cheaper window ones like Haiers.