8 possible reasons behind AC not cooling properly

Air conditioner not cooling

What you least want on a hot summer day is an air conditioner that can’t cool. There can be several reasons behind AC not cooling problem, some of which are technical faults and some are non- technical.

Most common reasons behind AC not cooling are:

1. Clogged air filter

If the air conditioner does not cool, the air filter might be clogged. In such case, air cannot flow through properly which greatly reduces the cooling capacity of the air conditioner. Either clean the air filter or replace it as needed.

Our Pick

Here are some more Air Filters that acts as Air Purifiers as well available online:

  1. Nirvana Being Nanotech Split (Wall-Mounted) AC Filter
  2. 3M AC Filters for converting Split AC into air Purifier [Dust, Pollen & Allergens, 4 Sheets, 2 Change Indicators]
  3. 3M AC Filters for converting Split AC into air Purifier [Dust & Pollen, 4 Sheets, 2 Change Indicators] 
  4. 3M Anti Pollution Filter for Converting AC into Air Purifier

2. Dirty coils

If the air conditioner is not cold enough the condenser coils may be dirty and loaded with debris. In an AC, the condenser is like a radiator that dissipates heat (which was removed from the air). The condenser coil must be clean to dissipate heat outside. As the coils get dirtier the air conditioner becomes less efficient, which makes it work harder to cool the room. If the coils are dirty enough, the unit will never be cold enough and will not be able to cool the room.

Our Pick

If you wish to clean DIY, we have some more recommendations for you:-

  1. Stainless Steel Fin Comb Brush for AC Blade Radiator Cooling Straightening Cleaning Tool 
  2. Real Life Solution Plastic AC Fin Comb Set, Straightener, Cleaner, Condenser, Evaporator, Cleaning Tool (Blue)
  3. KetZeal Plastic Cleaning Tool Kit Wire Brushes with Brass, Nylon, Stainless Steel Bristles (Set of 3)
Our Pick

To avoid dirt and mess while cleaning your AC Coils please consider these other recommendations as well:-

  1. Real Life Solution Split AC Wash Bag, Service Cleaning Cover, Servicing Kit with Apron (Black)
  2. Split AC Wash Bag, Service Cleaning Cover 

3. Insufficient coolant

The coolant circulates through the evaporator coils and cools the air flowing over it and eventually sends cool air into the room. So when the level of this coolant becomes insufficient, the AC fails to cool. At this stage call a PRO for coolant top up and refill.

4. Faulty compressor

A compressor is the heart of an air conditioning unit which is responsible for cooling your room. If the air conditioner does not cool, the compressor might be defective. The compressor is a motor which compresses the refrigerant or coolant and circulates the refrigerant through the evaporator and condenser coils. If the compressor goes bad the cooling cycle does not start and the AC fails to cool.

5. Faulty thermostat

A thermostat is a sensor that senses the room temperature and hints the compressor to start or stop the cooling cycle. If the thermostat is defective, the air conditioner does not cool or may cool continuously.

6. Defective parts

The other possible technical reasons behind AC not cooling can be a faulty run capacitor of the compressor, defective control board, bad thermistor, choked capillary, faulty motor etc.

Our Pick

Some of the commonly used Spare Parts you can get online:-


  1. Litost Li Capacitor for Air Conditioner AC 440Volt 50/60 Hz 50+6 MFD +-5% Heavy Duty (Match & Buy)
  2. Concap 50 + 2 MFD Dual Capacitor for Conditioner 
  3. Concap 45 MFD Capacitor for Air Conditioner 

Indoor Fan Motor

Our Pick

Outdoor Fan Motor

Our Pick
  1. Raptor Air Conditioner Motor 63 watt 1150 RPM Outdoor Unit RA 
  2. Raptor Air Conditioner Motor 118 watt 930 RPM Window Unit RA 262 
  3. Air Conditioner Motor 93 watt 1050 RPM Outdoor Unit RA 203 

7. High atmospheric temperature

An AC has an optimum operating temperature (surrounding temperature) at which it can work most effectively. If the temperature shoots up beyond the optimum temperature limit, the efficiency of the air conditioner goes down. Sometime it is so hot outside that a stage is reached where the compressor stops working completely.

8. Undersized AC

A common mistake people make is that they buy an AC based on their budget and not based on the requirement of the room. A small AC in a huge room will always find hard to cool the room in peak summers. The size of the AC should be according to the size of the room.

9. Faulty AC Remote

There can also be a situation when the remote fails to send temperature change signals to AC unit. A simple replacement of remote will do the trick. Here, are a few Brand specific AC remotes and a universal remote that you can get on Amazon via reputed sellers:

Our Pick
  1. Remote Compatible for Voltas Smart Split Ac Remote Control with WiFi Function
  2. Remote Compatible for O General Split AC
  3. Remote Compatible for VOLTAS/Onida/GREE/ELECTROLUX/GODREJ AC 
  4. Upix® AC Remote No. 68 with Backlight & Timer, Compatible with Hitachi AC 

Recommendations for saving AC Electricity Consumption

If you enjoy the cool air from your AC but are sweated at the end of the month after seeing your electricity bills, then there is a robust system that can help you save a huge amount of money and power savings over a long period of time. Check out this AC Module that helps run all your heavy duty home appliances for more than 25 years.

Other than that, if your AC is not cooling, you can always book a case with Mr Right.

For more information on AC care and maintenance refer to Ideas by Mr Right

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  1. 1

    The detailed insights and practical tips are incredibly helpful. Thanks for shedding light on this common issue with such clarity. Definitely bookmarking this for future reference!

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    Home Appliances Repairs has been the ultimate provider of all your home appliance complications for decades. You might have heard about us as Gurgaon’s most trusted doorstep Home appliance repair and maintenance company.

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    “Thank you for this insightful article on the possible reasons behind AC not cooling properly. The concise breakdown of eight potential issues is incredibly helpful. Understanding these factors will undoubtedly save time and frustration when troubleshooting cooling problems. Your expertise shines through, making it easier for readers like me to address AC issues with confidence. Great job!”

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    Welcome to Smart Home Castle, where we share our knowledge for Home Automation. We’re passionate about making your home smarter and more comfortable, Stay up-to-date with the latest trends, products, and tips in the industry, Join our community and discover how technology can transform your home.

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    Many thanks to the authors for their expertise and dedication in providing such a comprehensive and helpful resource, which serves as a guiding light for homeowners and HVAC professionals navigating air conditioning challenges.

  11. 11

    Thanks for sharing valuable Information. You can Install AC Modules for your home To reduce your electricity bills and this solar system will run all your home appliances for more than 30 years.

  12. 12

    That’s right, it’s important to replace the AC filter regularly, as a clogged filter can lead to serious damage to your air conditioning system. While it’s standard to change an AC’s air filter every three months, it’s better to change it every 60 to 90 days, especially if you have seasonal allergies or pets.

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    I just wanted to let you know that I just looked at your website and found it to be very interesting and helpful. I’m looking forward to reading many of your posts quordle

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    This is a very interesting subject, and I want to learn more about it, but I don’t know where to start. You started this talk, which is great, and I hope that everyone will be able to help me quordle

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    I can personally relate to this issue as I experienced it last summer. My AC was constantly running, but the room temperature remained unchanged. After reading your article, I realized that a faulty thermostat could have been the culprit behind my cooling woes. Thank you for shedding light on this particular aspect of AC maintenance. Your article has empowered me with the knowledge to address potential thermostat issues and take appropriate action.

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    Clean and change filters regularly for efficient system operation and to prevent dust, dirt, and mold buildup. Check for leaks or blockages to avoid damage. Get an annual inspection from an HVAC technician to identify and address potential issues early.super general ac

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