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What Causes Your Air Conditioner To Freeze Up? What Causes Your Air Conditioner To Freeze Up?

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What Causes Your Air Conditioner To Freeze Up?

Written by: Emily Roberts

We list out the unknown hidden reasons that can cause your AC to freeze up. See how you can unfreeze your AC in a few seconds without any professional help!

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Is your Air conditioner freezing up? If you have spotted some of it, wondering why? There could be several reasons for an AC unit to freeze up. Waking up to find your AC freezing is not that pleasing, it can run a chill down the spine leaving you feeling warmer.


We take a quick run to help you crack the cause, as we bring you the most probable reasons why is your Air conditioner freezing up.


1. A dirty air filter behind the plot

Dirty air conditioner Filter with a lot of dust.


Head out to check your filter, if it has been a considerable amount of time since you have given it a good wash or if your filter has accumulated a substantial amount of dust on it. Then it is probably the prime cause why you see your AC freezing.


A dusty filter can cause low airflow and this can add a load on the compressor and other components of the AC. In the continuing instances of low airflow, the evaporator coil receives less air for cooling. It is important that the coil receives an adequate flow of hot air to prevent it from freezing.


Clean the filter, and it should take care of that AC unit freeze up issue!


2. Must be the thermostat

Thermostats in air conditioner


Watch out for thermostats. If the thermostats are set too low it can cause the air conditioner to run for long and cause the temperature of the condenser to drop below the freezing. Unnecessarily running an air conditioner all night is a waste of energy and can be really heavy on the air conditioner. The overtime running can cause your AC unit to freeze up.


Want to keep away the chances of a faulty thermostat which leads to AC freezing? Keep a close eye on the thermostat, or resolve any faults. This should possibly help you melt it down!


3.  Fan speed might result in AC freezing

fan inside an air conditioner


Reach for the fan! The fan could be slow and it can lead to a freeze build up.


In the absence of a fast fan, the air flowing through it is not enough on the job and it leads to a condition where AC coil freezes up to a much higher level.


Don’t try your hands on it, it is a professional’s zone. All you need to do it is call a technician who can easily get the fan blow harder. It is important to keep a sufficient amount of air to blow over the evaporator coil.


4. It can be a block in the drainage

A block in the drainage can be a lead factor for the AC coils to freeze up. Normally the water drips down to fall in a pan from where it is drained.


In situations where there can be a block anywhere in the drainage pipe, the water is not drained out properly causing water to collect. These liquid starts to freeze up and the freeze builds till the evaporator coil and AC coils freeze up and then it intensifies.


Watch out for the dripping water to the pan and make sure it is making its way out the floor drain.


A weekly quick check on the drainpipe can be helpful, especially if the atmospheric heat is high. Make it a part of your routine checklist and it should help you beat the heat without any interruptions.


This can save you from AC coil freeze-up hassles.


5. Low Refrigerants?

Refrigerants in Air conditioner


It could possibly be running on low level of refrigerants! This results in air conditioner freezing up.


Refrigerants are a non-corrosive gas or liquid used in machines where the exchange of heat is involved. The refrigerant chlorofluromethane otherwise known as R22 has an important role in your air conditioner.


In an off chance if there was a fault in loading it or if there is a leak, it can lead to situations where the levels of the refrigerants can fall low. The low levels of refrigerant can trigger in the evaporator coil to go too cold.


As the system starts to build up ice, there is a high chance that underperformance of the system goes unnoticed. But sooner when ice deposits it will hit the AC unit’s performance.


It is recommended to call a professional service that can check the situation who can set it right either by recharging the unit or by fixing the leak, what so ever is appropriate!


6. Closing supply vents


It is a normal practice to close the vents of unused rooms and this is done to cut the electricity bills and save on the energy, but be careful, if you are on a mission to save your electricity bills by closing more vents, it can lead to a costly affair, it could lead your air conditioner freezing up.


Take advice from a professional before you make a decision to close supply vents. Closing the supply vent may cause low airflow which will give warm air to the coil and continuing this situation can cause the evaporator to get colder, leading AC coils to freeze up.


A small negligence can lead to a heightened situation where it may even lead to destroying the compressor


7. A wrong angle window tilt

A window angle might not seem easy, it may not seem to be a contributing factor towards that ice buildup! But it can!


When you spot the Air conditioner freezing up, an improperly tilted air conditioner window is to be looked for.


The window must be tilted a little higher with the inside portion. If this is not kept so, the water will cease to exit through the drain hole. And might result in water staying back inside the unit which can eventually build the freeze.


This is another reason that can result in the Air conditioner freezing up. Tilt that window right, beat the heat –tilting that window right can save from building a freeze.


There can be a host of underlying issues -mechanical issues, a dirty filter, block in the blowers, shutting down the supply vents, drain block, thermostat game, refrigerant related issues – it can be issues with the refrigerant line, low refrigerants or too much of it can be damaging and yes, the reason could be as simple as the little angle on the window. By now you would have figured out what was going the wrong way.


What if you could not spot it till now? Then perhaps it demands a professional to look into the matter, bringing in an expert could be the best decision ever. Sometimes you may need a new AC. Now what can be important to decide is to keep or get a new one. Time to make an appropriate decision so that it should not let you run into expensive affairs or leave you sweating.


It is important to know what to do immediately when you spot the freeze.


freezing air conditioner


• Switch the power off – it is not only safe but also you save on the electricity bills and of course you don’t want to risk your compressor.
• Wait for the meltdown – hunt for any block from the condensate drain and allow the meltdown.
• A slight backward tilt of your window AC unit melts ice to drain out.
• Fast forward the melt-a blow dryer or any smaller size fan can let it blow to the evaporator coil. Another alternative to help the meltdown is to turn on the AC fan, but be sure not to turn the compressor to run in any chance, this can help the ice to melt fast.

• Empty the drain pan and now the air conditioner can be turned on.


The above steps are a DIY and can help you melt the ice and your AC is ready to beat the heat.


An AC Freeze can be mended easily most of the times, but for sure it puts you in the heat and needless to say it can be exasperating and annoying to fix it in the heat. As we have summed up how you can find out what had caused the Air conditioner freezing up.


Sometimes it can be a single issue that is underlying or a couple of issues, so it is important to decide whether to keep running it or get a new one.


However, there are some ideal practices that can be followed to keep your unit hale and healthy rather than waking up one fine morning and discovering a freeze on it.


Check out the thermostat, clean the filter and change it if it calls for a new one, increase underperforming fan speed, the supply vents should be kept open, keep a check on the condensate drain, correct those window angles and get a professional examine the performance and the machine components.


Doing these can save you a lot, and happy AC Freeze free days!

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