residential air conditioning

Why is My AC Freezing Up?

Air Conditioning Unit

Table of Contents

  1. The 7 Most Common Reasons for AC Freeze-ups Are
    1. Issue With Refrigerant
    2. Poor AC Heat and Ventilation System or AC Feels Suffocated
    3. The Thermostat and Fan Setting Inaccurate
    4. Oversized AC
    5. Inefficient Compressor
    6. Blockage in the Drain Pipeline 
    7. Dirty Air Filter
  2. Try these Fixes Before Calling an HVAC Professional

Air conditioners(AC) are a must-have in most London houses, especially during the hot summer. However, Air Conditioning units can malfunction and start to freeze. When we say an AC system is “freezing up,” it means that ice or frost is forming on the components of the system, particularly on the evaporator coil. Typically, the evaporator coil absorbs heat from the indoor air, cooling it down before sending it back into the room. However, several factors can cause the coil to become excessively cold, forming ice or frost. This can be a frustrating and costly problem, but there are various reasons why your air conditioner may be freezing up.

The 7 Most Common Reasons for AC Freeze-ups Are

1. Issue With Refrigerant

Refrigerant is the cooling liquid that is responsible for covert humid air into the cool air but if the refrigerant liquid is leaking or in less quantity it starts freezing up on the evaporator coil causing AC to freeze up.

2. Poor AC Heat and Ventilation System or AC Feels Suffocated

This is one of the main causes for your AC to freeze up because of improper airflow/Ventilation System. This basically means your AC doesn’t get enough air to operate properly leading the coil temperature to freeze up. The humidity in the air adds up to the greater build-up of ice in the coil eventually AC freezes up.                                               

3. The Thermostat and Fan Setting Inaccurate

AC works on the predetermined temperature range they can’t function easily if the outside temperature is below 60 ℉. Thermostats are responsible for the regulation of temperature in your house. Also, If your system blower fan is faulty, it decreases the system’s performance leading to high energy bills and a freeze-up AC. In case, you fail to set your thermostat or fan setting call your Air conditioning maintenance company for an immediate solution.

4. Oversized AC

This generally happens in big window AC that serves the small room. An oversize AC is often switched on and off to maintain the temperature of the room causing moist air to condense on the coils and the AC to freeze up. 

5. Inefficient Compressor

If the compressor is unable to pump the refrigerant properly, it may trigger a malfunction in the AC by elevating the temperature above the range and automatically shutting it down. Because of this moist air gets condensed on the coil and causes AC to freeze up.

6. Blockage in the Drain Pipeline 

When the AC drain line becomes clogged, it doesn’t allow condensed water to flow freely to the exit. This means excess moisture is trapped in the AC system resulting buildup of ice on its components as more ice accumulates and thickens causing AC to freeze up.

7. Dirty Air Filter

This is the most common reason for AC freezing up since air filters have a significant impact on the airflow. A dirty air filter decreases airflow making ventilation poor causing excess moisture and moist air trapped in the AC which eventually leads to AC freeze-up.

Try these Fixes Before Calling an HVAC Professional

If you notice that your AC unit is freezing up, it is important to take action to fix the problem. Here are a few fixes

  • Check the refrigerant levels: Look for indicators such as AC taking a long time to cool, high electricity bills, hissing or bubbling sounds from the AC, and so on, which indicate that the refrigerant levels are low. You will need to have an HVAC professional from your air conditioning company add more refrigerant.
  • Clean the filters: You can clean the filters yourself using a vacuum cleaner or a brush.
  • Clear blocked vents: If you can see that they are blocked, you can clear them yourself using a broom or a vacuum cleaner. If the vents are in walls or ceilings, you may need to call a professional from an air conditioning maintenance company to clear them.
  • Reduce the workload on your AC unit: If it is very hot outside, you can reduce the workload on your AC unit by opening windows or turning on fans.

If you have checked the refrigerant levels, cleaned the filters, and cleared any blocked vents, and your AC unit is still freezing up, you may need to have an HVAC technician from Hamilton Air Conditioning, an Air Conditioning Service company offering air conditioning installation, repair and maintenance services. get check the whole AC unit for other problems.

Matthew Connery
By: Matthew Connery

Matthew Connery is the Director of Hamilton Air Conditioning in London. He is a skilled Business Strategist who delivers energy-efficient and cost-saving solutions to commercial and domestic clients from leading air conditioning brands. 

Jul 07 2023