Aircon Thermistor Essential Guide & FAQs

Dive deep into the workings of your air conditioner by mastering the function and significance of aircon thermistors, laying the groundwork for more efficient cooling and a comfier home.

The Role of Thermistors in Air Conditioning Units

A close-up of a thermistor sensor in an <a href=

Thermistors play a key part in keeping your air conditioning unit working right. They are special temperature sensors that sit near the evaporator coils and outside the condenser unit of your air conditioner.

These smart parts watch the room’s heat and tell your AC how to keep the place feeling just right.

If a thermistor stops working well, you might notice that your AC isn’t keeping things as cool as it should or is giving out cold air in short bursts. It’s important to keep an eye on this because it makes sure you stay comfortable and can help stop big problems with your air conditioner later on.

Symptoms and Consequences of a Faulty Thermistor

A broken thermistor inside an air conditioning unit in a warm living space.

If your air conditioner starts blowing cold air in short bursts, you might have a problem with the thermistor. This small part measures the room temperature and tells your AC when to cool down or warm up.

When it doesn’t work right, your aircon can act strangely, like cooling too much or not enough. This makes your home feel uncomfortable.

A broken thermistor also means more stress on your AC system. It can make parts wear out faster and cause bigger problems down the line if you don’t fix it soon. You could end up needing costly repairs or even having to replace the whole unit sooner than expected.

With replacement costs ranging from $90 to $250, fixing a faulty thermistor early helps save money in the long run and keeps your air conditioning system running well.

Thermistor vs. Thermostat: Know the Difference

A photo of an industrial thermostat and thermistor in an HVAC control room.

Thermistors and thermostats both keep an eye on temperature but in different ways. A thermistor changes its resistance when the temperature goes up or down. This change tells your air conditioner how much cool air to make.

It’s smart—like a detective who knows just how cold or warm things are getting.

A thermostat is like a boss that sets rules for the heating and cooling systems. It waits for your say to start making the room warmer or cooler based on where you set it. Think of it as a remote control for comfort, telling your HVAC system when to get going and when to take a break from working hard to keep you cosy.

Both parts need each other to make sure your space stays just right – not too hot, and not too cold. Keep them happy, and they’ll work together to give you the best chill-out spot or cosy nook without fuss or trouble!

Maintenance Tips: Replacing and Testing Your AC’s Thermistor

A workshop scene with tools and air conditioning unit.

Keeping your air conditioner in top shape means checking on parts like the thermistor. If you spot issues with temperature control, it might be time to replace or test your AC’s thermistor.

  • Turn off your air conditioner completely. Make sure there is no power going to the unit before you start any work.
  • Locate the thermistor. It’s usually near the evaporator coils or outside near the condenser.
  • Carefully disconnect the wire connector from the thermistor. You might need to use a small tool to release it.
  • Remove the old thermistor from its place. You can do this by slowly pulling it out of its clip or holder.
  • Get a new thermistor that matches your AC model. Using one that isn’t right can cause more problems.
  • Install the new thermistor where the old one was. Push it gently into the holder and make sure it’s secure.
  • Reconnect the wire connector to your new thermistor. Ensure that it snaps in place properly so there are no loose connections.
  • Test the new thermistor with a multimeter. This tool can tell you if your thermistor is working as it should by measuring resistance changes as temperature changes.
  • Turn on your air conditioner and check if it works correctly now. Pay attention to how it cools and cycles off and on.

The Cost of Ignoring Thermistor Issues in Your AC

A malfunctioning thermistor surrounded by broken AC parts in a workshop.

Ignoring a bad thermistor in your air conditioner can hit your wallet hard. A small problem today can lead to bigger, more expensive issues later. If the thermistor isn’t working right, it might not sense temperatures correctly.

This means your AC could keep running when it doesn’t need to, wasting electricity and raising your bills. Over time, this extra wear and tear on your air conditioning system can cause parts to break down sooner.

Fixing or replacing parts like fan coil units or condenser coils costs way more than sorting out a faulty thermistor early on. The price you pay for a new thermistor is small compared to these big repairs – between $90 to $250 could save you from spending thousands later on.

Plus, when an AC runs inefficiently due to ignored maintenance, it struggles and uses even more power. This leads to even higher electric bills every month, making the cost of looking past little fixes much greater in the long run.


A close-up of an air conditioning unit's thermistor surrounded by internal components.

Fixing your air conditioner’s thermistor keeps everything running smoothly. Remember, it checks the temperature and talks to the AC to cool your room just right. If it breaks, you’ll get cold air in bursts, not all the time.

Changing a bad thermistor costs some money but saves trouble later on. Look after your AC, and it will keep you cool when you need it most!


1. What is an aircon thermistor?

An aircon thermistor is a temperature-sensing device in your air conditioner that measures how hot or cold it is and helps control the temperature of the air that comes out.

2. Why does my air conditioner need a thermistor?

Your air conditioner needs a thermistor because it uses the resistance signal from this part to figure out the right amount of cold air bursts to keep the room at your chosen temperature.

3. How do I know if my thermistor isn’t working properly?

If your room doesn’t stay at the right temperature, or if your air conditioning system blows too much or not enough cold air, then your thermistor might not be working well.

4. Can I help my thermistor work better?

Yes! Make sure you vacuum and clean your filters often so they don’t block airflow and change them when they’re old. This helps all parts of your air conditioners, including ambient temperature sensors like the thermistor, work better.