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What Should You Do When Your Air Conditioner Won’t Shut Off?

If your Louisville air conditioner won’t shut off, the temperatures in your home may be too cool for comfort. Excessive cool air also costs a lot more, due to electrical power that is wasted by your system. If your air conditioner will keep running no matter what repair you try, malfunctions or faulty components are to blame. You could have a dirty air filter, clogged condenser coils, frozen evaporator coils, a broken relay switch, or a bad thermostat, amongst other common air conditioner issues.

When your air conditioning unit stays on for hours on end, Jarboe’s Heating, Cooling & Plumbing shares why and what to do to right the wrong. When you need professional repairs for an air conditioner that keeps running, contact our team anytime – emergency AC repairs are available.

Should Air Conditioners Run All the Time?

A normal air conditioner does not run all the time. Typically, an air conditioner runs two to three cooling cycle each hour, with each cycle lasting 15 to 20 minutes. Depending on outdoor temperatures, cycle time may be a bit or more less than this estimate.

If your cooling system has been running for hours and shows no signs of stopping, this is a problem that calls for repair right away. When air conditioners won’t shut off, they waste a great deal of electrical power. The extra operating time increases the amount of wear and tear to system components, causing them to break sooner and increasing the number of repairs needed.

Why Won’t My Air Conditioner Shut Off?

If your air conditioner won’t shut off, an issue in one of the following categories is likely the cause behind the conditions you are experiencing.

1. An Electrical Problem

Inside the condenser unit and indoor equipment, there are a number of electrical components and connections that can malfunction, causing an air conditioner to remain on. A relay switch or capacitor stuck in a closed position continues to let the compressor or other vital components receive power. So, the system will continue to run, even when it should not. It may be possible to fix a switch that has stuck in one position, but often they need to be replaced.

2. Incorrect Thermostat Settings

When it comes to incorrect thermostat settings, it’s not that your air conditioner cannot turn off, it’s that the system is not set correctly to turn off when you think it should. How you set the fan and temperature on your thermostat can impact this issue.

  • If your fan is in ON mode instead of AUTO, it constantly runs. Normally, a blower fan only runs during a cooling cycle to circulate cool air from room to room. When the fan is left on all hours of the day, it’s possible for a homeowner to mistake its operation with the actual cooling unit and think that the air conditioner won’t shut off.

  • If someone in your home has adjusted the set temperature lower than usual, your air conditioner may keep running long past when you expect it to turn off. When set temperatures differ from one’s usual preferences, it may appear that your air conditioner is running when it should be resting.

3. Thermostat Malfunctions

A thermostat has a useful life of around 10 years. As time goes on, dirt can collect on temperature sensors, causing the thermostat to misread room temperature – as such, the thermostat may leave your air conditioner running after it should have ended a cooling cycle. Damage to electrical wiring and loose wiring connections can disrupt signals sent from the thermostat to the air conditioner, causing it to cycle longer than it should.

4. Problems with Fan Limit Switch

The thermostat settings control fan operation, but if the fan limit switch is stuck in the override position, the fan will continue running even when the thermostat instructs it to turn off. If the fan is constantly running due to a bad limit switch, it may feel like your air conditioner won’t turn off. The switch needs to be reset or possibly replaced if damaged.

5. Dirty Condenser Coils

Refrigerant carries heat from the evaporator coils inside your home out to the condenser coils within your outdoor unit. The condenser coils release heat into the surrounding air, ridding your home of hot air. Dirt and debris from outside accumulate on the condenser coil, limiting the area available to exchange heat. When the coil is dirty, the air conditioner must run longer to cool the home. Coil cleaning is usually performed during annual maintenance.

6. Clogged Condenser Unit

Sticks, leaves, grass, weeds, and other organic matter can stick along the fins of the condenser unit, effectively blocking air from flowing through it. Without good airflow, the condenser coil doesn’t release heat as effectively so the cooling system must cycle longer to maintain comfortable indoor temperatures.

7. Frozen Evaporator Coils

Evaporator coils inside the air handler can freeze if they do not encounter adequate heat. This often occurs due to a dirty air filter, low refrigerant, or other airflow blockage. A clogged condensate drain line can worsen ice accumulation on the coils. When the evaporator coils are frozen, they are unable to absorb heat from the indoor air, so the air stays hot.

8. Dirty Air Filter

If your air filter is used for too long, it will become clogged with contaminants. When this occurs, it is exceedingly difficult for air to pass through it. Your air conditioner must work extra hard to circulate air for cooling, meaning the system spends more time cycling than usual.

9. Undersized Air Conditioner

An air conditioner must be the right fit for a home, and homes as well as air conditioners come in many sizes. If the air conditioner installed does not have the cooling capacity the home requires, the unit simply isn’t powerful enough to deliver the cooling desired by the family. An undersized air conditioner will run seemingly around the clock as it unsuccessfully attempts to deliver the cool air needed in each room of the home.

Air conditioners that are too small for the spaces they serve waste a great amount of electrical power with cycles that last for hours on end. These systems experience wear at a faster rate than correctly sized systems, so they break down more frequently and need to be replaced sooner.

How to Fix an Air Conditioner That Won’t Turn Off

If your air conditioner system does not turn off, these troubleshooting tips may help you put an end to the cooling cycles that last for hours.

1. Change the Thermostat Settings

Make sure the thermostat is appropriately set to stop air conditioner operation. Adjust the temperature setting so it is a few degrees higher than the current room temperature – this should cause the thermostat to signal the air conditioner to shut down. Next, set the fan to AUTO. If the fan was ON, moving to the AUTO setting should cause the fan to stop while the air conditioner is between cooling cycles.

2. Change Air Filter

Inspect your air filter and replace it if it is covered in pollutants. A clean filter will allow air to freely flow through the air conditioner so cycles don’t run longer to make up for this hurdle.

3. Clean the Condenser Unit

Airflow restrictions also start outside, caused by clogged condenser units. Take time to remove debris from the fins of your outdoor unit and remove any vegetation growing along the sides of the unit.

4. Open Room Vents

If vents in your home are closed, open the supply vents in every room. This allows the air conditioner to deliver the proper amount of cooling for the entire home, and no air backs up in the duct system where pressure can impact comfort and temperature balance.

5. Clean the Blower Motor Fan

Grime and dirt buildup on the blower’s fan blades can cause it to revolve at a lower speed, impacting the air conditioner’s cooling capabilities. Use these instructions to clean this important component:

  1. Shut down power to the indoor equipment.
  2. Remove the panel covering the blower chamber.
  3. Loosen and remove screws on the circuit board and position it out of the way, if applicable.
  4. Loosen and remove bolts holding the blower assembly and carefully remove it from the chamber.
  5. Use a brush to clean away grime and dirt built up on the fan blades.
  6. Run a vacuum to remove debris and other matter from the blower assembly and chamber.
  7. Reposition the blower assembly in the chamber and tighten its screws. Reposition and secure the circuit board, if needed. Replace the blower chamber access panel.
  8. Restore power to the indoor unit.

Call Jarboe’s for Air Conditioner Repair in Louisville

If your air conditioner won’t stop running, it’s time to contact Jarboe’s for professional repairs. Our technicians find the source of your cooling troubles and fix faulty components so your cooling system operates with flawless performance into the future.

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