When your air conditioning system won’t turn off, you’ll notice that your electricity bills climb higher. The AC parts and components will also wear out faster and eventually become damaged as the system works overtime.
If your air conditioning system won’t turn off, there are most likely malfunctioning mechanisms, such as a faulty thermostat or fan limit switch, frozen evaporator coils, electrical issues, or incorrect thermostat or fan speed settings. High outdoor temperatures and a too-small AC unit can also cause problems with your HVAC settings.
In the end, you’ll end up wasting money on high utility bills and AC system repairs and replacements. Fortunately, it’s possible to troubleshoot the AC issue by adjusting the thermostat and fan settings, removing airflow restrictions, and cleaning the fan blower and condenser.
The best solution to find the root cause of your air conditioner issues is with the help of an HVAC professional.
In this article, learn about the main reasons why your AC won’t turn off. From there, it’ll be easier to find an effective troubleshooting method.
Is it okay for an Air Conditioner to run all day?
Even if outdoor temperatures are unusually high, your air conditioner shouldn’t run constantly for several hours.
The standard cooling cycle lasts only 15 to 20 minutes, occurring twice an hour. Once the desired temperature is reached, the AC should turn off automatically to end the cooling cycle.
Malfunctioning air conditioner parts can affect other components and mechanisms that prevent the AC from shutting off. If your AC system has this issue, call an HVAC expert to avoid wasting electricity and further damaging the unit.
Why won’t my AC turn off?
If your AC won’t turn off, it’s important that you find the cause of the issue so that you can either repair or replace the malfunctioning component. In some cases, you may only need to clean parts that restrict airflow or adjust incorrect settings.
- Faulty thermostat: If sensors or electrical wiring are damaged, the thermostat can’t relay accurate readings to your AC. It should be replaced every 10 years for optimal efficiency.
- Wrong thermostat settings: When the AC fan is turned On instead of on Auto, the fan and motor will run continuously even when the cooling cycle is off.
- Issues with electrical components: If your AC doesn’t switch off, there might be a short circuit issue. Call an HVAC professional immediately for assistance.
- Faulty fan limit switch: if the fan limit switch is stuck in override, the fan motor will continue running even when the AC isn’t cycling.
- Dirty condenser and condenser coils: If the coils and condensers are blocked by dirt and debris, the AC’s cooling capacity is reduced. This will force the system to work harder to achieve the set temperature.
- Dirty air filter: Clogged air filters cause the AC to cycle continuously to reach the set temperature.
- Frozen evaporator coils: Frozen evaporator coils caused by dirt build-up or clogged drain lines, air vents, and air filters prevent the refrigerant from absorbing heat.
- Low fan speed: The AC system will keep cycling to achieve the desired temperature if the fan speed is too slow.
- Air conditioner is too small: If the air conditioning system is too small for your room, it will work inefficiently for hours without adequately cooling the room. This issue generally pops up during scorching summer days. To check if your unit is too small, increase thermostat temperature settings 5 to 10 degrees. If the unit shuts down, the AC is most likely too small.
Troubleshooting tips: What to Do When Your Air Conditioner Won’t Turn Off
As you can see from the previous section, there are several possible reasons why your AC won’t turn off. Before calling an HVAC service, you can try these troubleshooting tips:
Adjust Thermostat Fan Settings
When the thermostat fan setting is ON, the fan will continue running alone even without the cooling cycle. Make sure to toggle the settings to Auto.
This will run the fans and cooling system simultaneously to reach the desired room temperature. When the temperature is achieved, both mechanisms will shut down after each cycle.
Adjust Thermostat Temperature Settings
To test if the thermostat caused the issue, raise the current thermostat temperature by a few degrees. The AC should turn off once it reaches the set temperature.
If the air conditioner still doesn’t turn off, the problem is most likely with the thermostat sensor or wiring. Call an HVAC professional for thermostat replacement or repairs.
Remove Air Flow Restrictions
When airflow is restricted, the air conditioner efficiency is reduced, forcing the system to work longer. When the components of the cooling system have an extra layer of dirt, the system needs to work harder to reach the programmed thermostat temperature.
To fix this issue, make sure to replace the air filters regularly. According to experts, you should change air filters every month, especially if you have pets or live in a highly polluted area.
You should routinely remove the debris covering the condenser, condenser coils, and evaporator coils to optimize cooling. If you don’t have experience cleaning these components, we recommend that you hire an HVAC professional since the process requires special equipment and tools.
If you plan to clean the condenser and condenser coils yourself, follow these steps:
- Use a water hose to remove loose debris, such as leaves, grass, dust, insect nests, and branches.
- Once surface debris is removed, use a sponge to apply commercial condenser cleaner or a solution of water and soap. Take extra caution if you’re using a spray to apply the cleaners.
- Leave the cleaner for 10 to 15 minutes.
- Use a sponge or a soft brush to wipe down the condenser and condenser coils.
- Rinse the excess soap and cleaner using a water hose. Let the parts dry before testing them.
Cleaning evaporator coils works similarly, but you need to open the access panel to remove the evaporator coils. You can use a brush or an air compressor to remove the surface dirt. Similar to cleaning the condenser, use a commercial cleaner or mild soap and water to clean the coils before replacing them in the AC compartment.
Clean the Blower Fan and Fan Blades
A dirty blower fan restricts air circulation, while dirty fan blades can slow down fan speed.
Make sure to remove the debris from the blower motor and the fan blades to ensure that the fan settings are working as intended.
Follow these steps to thoroughly clean the fan system of your air conditioner:
- Turn off the AC and remove it from the electrical outlet.
- Remove the access panel screws and fasteners. You should see the blower compartment.
- Carefully unscrew the circuit board from its place. Keep the wires connected when you move the circuit board out of the way.
- Remove the screws to dislodge the blower motor assembly, then slide it out of the compartment.
- Use a soft brush to remove the debris from the fan blades and the cabinet. Use a vacuum or air compressor to remove dust and debris. You can also use mild soap and water to remove the debris, but be careful to wipe it down thoroughly.
- Slide the blower back into the compartment and secure it with screws. Reposition the circuit board back into its place and secure it with screws.
- Reattach the access panel.
Need help with your Air Conditioner? Call us today for your AC Repair needs.
If your air conditioner won’t turn off, there are likely malfunctioning components or dirty components.
If the issue is caused by dirty air filters, condensers, evaporator coils, fan motor, or fan blades, try clearing the debris build-up to enhance airflow and cooling. You can also try adjusting the thermostat temperature or fan settings.
However, if the problem is caused by malfunctioning components such as a faulty thermostat, relay switch, or fan limit switch, or if it’s a short circuit problem, you need to call an air conditioner specialist. Aside from repairs, HVAC services can also replace your unit if it’s too small for your room.
At Complete Comfort in Central Indiana, we offer a full range of air conditioner repair, maintenance, replacement, and installation services:
- Air conditioner won’t turn off
- Air conditioner won’t turn on
- Freezing and leaking components
- Hot or warm air from the air conditioner
- Inaccurate or malfunctioning temperature control
- Loud noises or unusual smells from the air conditioner
We also offer preventive maintenance plans for HVAC systems. You can also book our services for careful cleaning and servicing.
In case your HVAC system needs a quick tune-up, you can rest assured that our skilled technicians will arrive on-site with a fully-stocked vehicle. We’ll quickly identify and address your concerns. We only work with trusted and field-tested professional equipment to ensure that your HVAC system is properly serviced.
For 24/7 emergency AC repair needs in Greenwood, IN, call our skilled technicians at Complete Comfort at (317) 535-5073 or book our services online.
Brittany is a marketer, entrepreneur, and writer with previous business development experience in the home maintenance industry. She currently manages the marketing for Complete Comfort Heating, Air & Plumbing and has a passion for helping people by simplifying seemingly complicated topics related to home maintenance and repair.