Identifying and Addressing Malfunctioning Sensors in AC

Air Conditioner


Air conditioners are a vital component of modern living, ensuring comfortable temperatures in our homes and offices. However, like any other machine, they are prone to various issues, with malfunctioning sensors being a common problem. ALP Heating, a leading HVAC service provider, is here to help you understand and tackle these common air conditioner issues.

Understanding the Role of Sensors in Air Conditioners

Air conditioners consist of multiple sensors that help maintain the desired temperature by monitoring and controlling various aspects of the system. Some of the most important sensors in an AC unit include:

  • Thermostat Sensor: Located near the evaporator coil, this sensor measures the air temperature and compares it to the desired temperature set on the thermostat. If there is a difference, the AC will adjust its operation accordingly.
  • Refrigerant Pressure Sensor: This sensor monitors the pressure of the refrigerant and ensures it remains within the optimal range. If the pressure is too high or low, the AC may not cool effectively or could even become damaged.
  • Ambient Temperature Sensor: Positioned outdoors, this sensor measures the external temperature and adjusts the AC's operation to maintain the desired indoor temperature.

Common Issues with Malfunctioning Sensors in AC

  • Incorrect Temperature Readings

A thermostat sensor may malfunction and provide incorrect temperature readings, causing the AC to overcool or undercool the room. This could be due to a displaced or damaged sensor, dust or dirt buildup on the sensor, or electrical issues.

  • Frequent On and Off Cycling

If the thermostat sensor is malfunctioning, it can cause the AC to cycle on and off frequently. This can lead to increased energy consumption, wear and tear on the system, and inconsistent cooling.

  • Inefficient Cooling

A faulty refrigerant pressure sensor can result in inefficient cooling as the AC may not be operating at the optimal pressure. This can cause the unit to work harder, consume more energy, and shorten the system's lifespan.

  • AC Not Turning On

A damaged or malfunctioning ambient temperature sensor may prevent the AC from turning on, as it might interpret the outdoor temperature as too low for cooling.

Troubleshooting and Fixing Malfunctioning Sensors

  • Inspect and Clean the Thermostat Sensor

Gently clean the thermostat sensor with a soft brush or cloth to remove any dust or dirt buildup. Ensure that the sensor is in the correct position, not touching the evaporator coil or other components.

  • Check for Loose or Damaged Wiring

Inspect the wiring connections for any visible damage, corrosion, or loose connections. If you find any issues, contact a professional HVAC technician for assistance.

  • Test Sensor Functionality

Use a multimeter to test the sensors' electrical resistance and compare the readings to the manufacturer's specifications. If the readings are outside the acceptable range, the sensor may need to be replaced.

  • Consult a Professional

If you are unsure about diagnosing or fixing the issue, contact ALP Heating at 647-972-8714 or email us at [email protected]. Our experienced technicians can quickly identify and resolve any malfunctioning sensor issues in your AC.


Malfunctioning sensors in your air conditioner can lead to various common air conditioner issues, including inconsistent cooling, increased energy consumption, and reduced system lifespan. By understanding the role of sensors in your AC unit, you can ensure optimal performance and prolong the life of your air conditioner by repairing and troubleshooting these issues.

However, if you are uncertain about diagnosing or resolving sensor-related problems, it is best to consult a professional HVAC technician. At ALP Heating, we have a team of skilled and experienced technicians who can quickly identify and address any malfunctioning sensor issues in your AC system.

Don't let malfunctioning sensors compromise the comfort of your home or office. Contact ALP Heating today to schedule an appointment and ensure your air conditioner is functioning efficiently and effectively.