Why is My Air Conditioner Freezing Up?

It’s summer time now and outside temperatures can feel close to those in a blast furnace. You go out to check on your AC unit and are astounded to find it looking like a glacier; the machine is covered in solid ice! You are dumbfounded by the spectacle. After all, how do you explain all that ice right in the middle of so much heat? A frozen AC unit is a bizarre, yet common, sight and can happen even when air temperatures are soaring. To help you out of your conundrum and give you some insights on the causes of the problem, here are some possible reasons why your AC unit may be freezing:

1. The AC unit is low on refrigerant. If the refrigerant levels get too low, the cold coil in your AC’s unit gets too cold and water vapor in the air starts to form around it. The refrigerant could be leaking. Call an HVAC technician to have the leak fixed and the refrigerant topped off.

2. The airflow around the cold coil could be impeded. This could be as a result of a dirty air filter. The registers might also be blocked or not fully open. Shutting the cold air outlets for certain rooms could be the cause of the problem. Make sure all the registers are open and the air filter is cleaned and free of obstructions if freezing is an issue.

3. The fan might not be running at all or is running at a lower-than-adequate speed. Check to see if the fan is operating normally. If the speed is too low, change the fan speed setting to a higher level.

4. Running the AC unit all night during cold nights can also result in freezing up. The thermostat could also be faulty.

If your AC unit freezes up, make sure that you switch it off as quickly as possible. Continuing to run the unit can result in the compressor being damaged; if it does get damaged, you will quickly discover how expensive it can be to replace it.

If the outside air is very humid, the air conditioner is likely to condense a lot of water around it. This water collects into the drip pan and needs to be drained. If too much water collects in the drip pan, the cold coil of the AC unit might cause it to freeze. This ice is likely to block the AC unit’s drain hole. So keep the drip pan drained when humidity is high.

What To Do in the Event of a Freeze Up

If the AC unit freezes up without your knowledge, a number of problems are likely to arise. The ice is likely to block the AC’s air passages thus cutting off the flow of cold air to your house. Although the unit will continue to run, it will perform no useful work. This will result in a waste of electric power. If the AC’s tilt is towards your house, the condensed water is likely to drain right into the house. You can usually tell when your AC freezes up if the unit is running, but no cold air is being delivered.

In the event of a freeze up:

1. Turn off the AC unit’s power supply
2. If the AC is a window unit, tilt its housing gently so that it drains outwards
3. Locate the drain hole and make sure it’s not clogged
4. You can open up the AC’s ductwork and suck out excess water using a wet/dry shop vacuum
5. You can use a hair drier to expedite the thawing of the ice on the AC unit
6. Once the ice is all thawed and the pan fully drained, resume power

Ocean State Air Conditioning is a family-owned Jacksonville, Florida heating and air conditioning company that offers all its clients top-notch installation, repair, and maintenance services for HVAC systems, including AC units and heat pumps. We have highly trained and N.A.T.E-certified HVAC technicians, experienced in the repair and installation of a wide range of HVAC systems such as Trane and Carrier, among others. If your HVAC system is continually freezing, then there is a problem that requires repair. Call today and let us stop those freezes and save your HVAC system from unnecessary damage.

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