Why does my AC work sometimes and not other times?

Author: Wallace Wintheiser  |  Last update: Tuesday, January 20, 2026

When refrigerant is low, the A/C may work initially but struggle to cool over time. 2> Electrical Problems: Faulty wiring, a failing compressor clutch, or issues with sensors or switches can cause the A/C system to function intermittently. Electrical problems may result in the A/C working some days and not others.

Why does my AC work sometimes and not other times in my car?

AC Works Intermittently: When the air goes from cool to warm to cool again, you're experiencing intermittent problems. This is often due to a clog in the system, a failed compressor or compressor clutch, a faulty condenser fan, a clog in the system, or the actuator directing airflow has failed.

Why does my house AC work sometimes and not others?

If your AC is cooling but not working properly, it could be due to issues like a clogged filter, low refrigerant, or a malfunctioning thermostat. Other possibilities include a faulty compressor, dirty coils, or blocked vents, all of which can affect the system's performance.

Why does my AC only work sometimes?

Other possible reasons for fluctuating cold air include: A damaged or sluggish blower motor. Dirty coils. Thermostat-related problems that are affecting the cycles run.

Why does my AC not kick on sometimes?

The easy explanation for your AC not turning on is a thermostat issue. Double check your thermostat is on, set to “cool,” and that the temperature is set to a few degrees colder than the normal ambient temperature of your home. You may also need to replace the batteries.

Why my AC stops cooling after some time?

Why does my AC work sporadically?

Refrigerant Issues: Low refrigerant levels due to leaks can result in your AC working intermittently. A professional technician can identify and fix refrigerant problems. Electrical Problems: Loose or damaged wiring, faulty capacitors, or a malfunctioning compressor can cause your AC to behave erratically.

Why does my AC work at night but not during the day?

Another sign of a refrigerant leak is if your home stays cool at night or on cool days, but won't ever get cool on hot days. It's imperative to turn your AC unit off immediately and call a professional for AC repair in Phoenix if your unit is leaking refrigerant.

Why does my AC stop working then starts again?

Dirty air filters restrict air flow, which can cause your AC unit to start and stop again. Check your air filter and replace it if it's dirty.

Why is my AC sometimes cold, sometimes not?

If your central AC is not blowing cold air, the refrigerant may be the problem. The unit could be running low and need additional refrigerant added. The most likely cause of this is a leak. A leak not only keeps the AC unit from cooling properly, but also it can cause other issues within the home.

Why is my AC blowing intermittently?

Several factors can lead to intermittent cold air from your AC, including low refrigerant levels, a dirty cabin air filter, or a blocked evaporator drain. You're not alone if you've dealt with this frustrating issue.

What is the first thing to check when the AC stops working?

Check these issues when the unit won't kick on: Check the thermostat and adjust the settings if it isn't set to Cool and an appropriate temperature setting to call for cooling. Examine the house circuit breakers for the AC unit and reset any tripped breakers. Check the air filter and replace the filter if it's dirty.

Should I turn off AC if it's not cooling?

When you notice that your air conditioner isn't cooling, your first action should be to turn it off. This might seem counterintuitive—after all, you want your home to be cool. However, continuing to run an AC that isn't effectively cooling can cause further damage to the system.

Why is my AC running but not cooling?

There are a number of reasons why your air conditioner might be running but not cooling. It could be an issue with the thermostat, the compressor, or the evaporator coils. Or, it could simply be clogged with dust and debris, which is preventing it from working properly.

Why does my AC come and go?

Common Causes for AC Short-Cycling

Clogged air filters. Electrical problems. Thermostat issues. Dirty coils or frozen evaporator.

How much does it cost to replace an AC compressor?

On average, AC compressor costs range from $800 to $2,300, with most folks paying $1,200 for a new one. However, your price will vary depending on factors like the size and brand of your compressor. Before you schedule your replacement, read on to learn about all AC compressor cost factors.

How to check house AC compressor?

How to Check an Air Conditioner Compressor
  1. Turn off power. Unplug the AC unit to protect yourself from electrical shocks while checking the compressor.
  2. Remove the faceplates. ...
  3. Look for visible damage. ...
  4. Test the AC compressor with a multimeter.

How much does it cost to fix AC in a car?

On average, car AC repair costs run between about $430 and $520. However, if you need a new compressor, you can expect to spend $1,300 to $2,500 or more. Here's a breakdown of some of the most common car AC repairs and their average cost.

How do I know if my evaporator coil needs cleaning?

Here Are Five Telltale Signs That Your AC Coils Are Dirty And Need to be Cleaned
  1. Your electricity bill has been going up. ...
  2. Your unit seems to be running longer for no reason. ...
  3. Your home doesn't feel as cool as it should be. ...
  4. The Coil is Covered in Frost While Running. ...
  5. Higher Indoor Humidity.

Why would an AC need to be reset?

This issue is when a circuit breaker powers on, protecting your appliances from voltage hazards. Sometimes, after a breaker is tripped, your AC unit may not work as well as before. If you have it set at a cool temperature but all you're feeling is warm air — a quick reset is sometimes all you need.

What is AC short cycling?

Short cycling is the term used when the cooling cycle on an air conditioning unit is shorter than it should be. On a hot day, this will typically last 10 minutes and then stop for 10 minutes, and so on. On cooler days, the breaks will be longer. However, AC short cycling disturbs this pattern.

Why does my AC stop blowing cold air sometimes?

First, check your filters and coils for dirt and debris that may be impeding airflow. Once you've cleaned the filters and coils, run the air conditioner with just the fan so that the ice accumulation can melt off. If the AC still doesn't blow cold air, it could be that refrigerant levels are too low.

How cool should my house be if it's 100 outside?

For many of us, 70 degrees is the ideal indoor temperature, but when it is close to 100 degrees outside, your AC unit will be working quite hard to meet these expectations. Consider setting your thermostat at 75 degrees to 80 degrees in your home if the outside temperature is approaching triple digits.

Is it OK to turn on AC all night?

While it's safe to leave the AC running all night. But you must take care of how much energy it consumes or if the cool and comfortable air is spreading equally throughout the room. If you are running your AC for long periods of time then try to keep your home ventilated by turning on a fan.

How do I know if my AC is cooling properly?

It's cooler inside: One of the simplest ways to check if your air conditioning unit is cooling your home is to assess the indoor temperature. If it's cooler inside than outside, your air conditioning system is likely functioning correctly.

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