Why is My Air Conditioner Not Blowing Cold Air?

The first car air conditioners were developed for luxury cars in the 1930s. Devices for cooling the air inside vehicles started becoming common in the 1950s and by the later 20th century had become a standard feature for cars and trucks sold in the United States. When they work, auto air conditioners are a blessing. However, when they start blowing hot air, they can be a source of frustration.

A number of ways exist for a car air conditioner to break down. The most common reason drivers lose their cold air is not enough refrigerant. Refrigerant is used to create cold air. It is a gas in the system, and very small holes in a hose, seal or coupler can allow enough to leak out to prevent the creation of cold air.

Another potential problem is contamination. Over time the inside of the rubber hoses can deteriorate, and little bits of rubber can clog up various filters and other parts of the vehicle A/C system, preventing proper circulation of the refrigerant. A component could also be worn or broken. The first step for Eureka drivers who can't cool their vehicle is a thorough air conditioning inspection, looking for leaks and worn parts. In fact, Federal law requires an inspection before adding refrigerant. Some states do not allow topping off a leaking system.

Once any repairs are made, refrigerant is added. At the same time, special oil is added to the system. This oil cools and lubricates various components as it circulates along with the refrigerant. If you have a refrigerant leak, you also have an oil leak – and it's important that both be replenished for proper function and protection of your A/C system.

Sometimes a worn serpentine belt (which drives the A/C compressor) leads to belt slippage which puts additional strain on the compressor. Replacing your serpentine belt and belt tensioner on schedule will extend the life of your A/C compressor and other belt driven accessories.

Most car owners don't service their air conditioning until it fails, but it is crucial to maintain them for 3 reasons:


Unlike the furnace in your house, a car’s heating system does not involve a central heating unit that can be simply replaced. The system is actually a combination of components including the blower fan, thermostat, and heater core, which is usually located in a difficult to reach area under the dashboard and can take days to repair if minor issues are not immediately addressed. Regular maintenance includes checking hoses and belts, and ensuring the antifreeze is clean and filled to proper levels; it will help keep the whole system in good working order.


The compressor is the most important component of your car’s air conditioning system, so it’s no surprise that it’s also the most expensive part to repair or replace. Regular maintenance ensures proper refrigerant and lubrication levels, which reduces the risk of premature compressor failure. Also, the most common air conditioning system problems involve minor issues like blockages or leaks, which are much easier to deal with if caught early during regular maintenance. And as an added bonus, regular A/C maintenance can also improve your car’s fuel efficiency, leaving more money in your wallet for summer fun.


As part of any regular maintenance routine for your car’s heating and air conditioning systems, mechanics will check your cabin air filter and replace it if needed. Cabin air filters trap pollen, bacteria, dust, and exhaust fumes before the air reaches your dashboard vents and pollutes the air you and your passengers breathe. Dirty or clogged filters can cause a variety of problems, from musty odors to headaches, allergic reactions, or breathing problems from the fumes, so it’s crucial to replace the filter before it gets that bad.

Give us a call to schedule an A/C Inspection so you are not left in the heat!

PS. Two fun facts!


It might sound strange, but your car’s engine cooling system is directly related to the heating system. Engine friction and combustion produce heat during operation, and while most of it is expelled through the exhaust system, the remaining heat must be dissipated. A mixture of water and antifreeze circulating through the engine block and radiator releases the excess heat into the atmosphere, and on cold days, that heat can also be redirected into the car to provide warmth for you and your passengers. Without a properly functioning heating system, your engine could overheat on a hot summer’s day and—in a worst-case scenario—break down completely.


On chilly winter mornings, when you can see your breath but not through your windshield because of a pesky layer of frost, your air conditioning system is hard at work behind the scenes. By pulling humidity out of the air, the air conditioning system helps defrost and defog the windshield, so if you notice defogging issues on cooler “June gloom” mornings, it might be time to recharge the A/C system or have a mechanic check for leaks and damage.

Give us a call!

Eureka Brake & Automotive <br/>707.443-2122 <br/>www.eurekabrake.com

Revised from content contributed by NAPA Service Assistant