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The sizzling-hot summers in Houston, TX, demand air conditioning for relief. Your air conditioner will work particularly hard during the dog days of summer. If you happen to notice frost or ice buildup anywhere on your air conditioner, this is a cause for concern. Here are six possible reasons why this might happen and some guidance on when you should call for an air conditioner repair.

1. Dirty Evaporator Coil

Dust and other debris can build up on the evaporator coil of your air conditioning system. The evaporator coil is contained within the system’s indoor unit. A layer of debris on the evaporator coil interferes with the absorption of heat from your home’s air. If the refrigerant can’t absorb heat, your home’s air will stay warm. The moisture from the air will freeze on the coil. During a routine AC maintenance visit, our technicians clean the evaporator coil. This coil is fragile, and cleaning it isn’t something you should attempt to do on your own.

2. Clogged Air Filter

A clogged air filter is another common reason why air conditioners freeze up. When the air filter is dirty, air can’t pass through it. The lack of airflow makes the evaporator coil get too cold. The moisture from your home’s warm air will condense onto the evaporator coil. It will freeze there, forming frost or ice during each cooling cycle. You’ll notice that there’s barely a trickle of air coming out of your home’s vents. Your air conditioner will cycle more frequently. Eventually, this short cycling will cause your air conditioner’s compressor to overheat. To avoid this problem, set a reminder to check your air conditioner’s filter once a month. Replace the filter as soon as you see that it’s dirty.

3. Broken Air Handler Fan

The air handler’s fan blows warm indoor air across the cold evaporator coil. If the fan stops working or rotates at too slow of a speed, not enough warm air will pass over the coil. This will result in the coil freezing. It will also halt the flow of cool air into your home’s living spaces. If you hear a humming or buzzing sound from your air conditioner’s indoor unit, a malfunction with the fan’s motor is a likely cause. A broken air handler fan can be replaced by a trained HVAC technician.

4. Obstructed Condensate Drain

The condensate drain allows the condensed moisture from your home’s warm air to be drained into your home’s wastewater system. A clog in the drain causes the water to back up. If it fills the drain pan in the air handler, it could end up pooling near the evaporator coil. The cold refrigerant cycling through the evaporator coil could freeze this water. If too much water infiltrates the air handler, its system safety switch could shut it down. During a routine AC maintenance visit, our technicians clean the condensate line in order to prevent this issue.

5. Malfunctioning Thermostat

Thermostats are the control centers for heating and cooling systems. A malfunction in your thermostat could cause a cooling cycle to last for longer than normal. An excessively long cooling cycle will make the evaporator coil get extremely cold. This will result in condensation freezing on the coil. Malfunctioning thermostats should be inspected by an HVAC technician and repaired or replaced as soon as possible.

6. Refrigerant Leak

The chemical refrigerant in your air conditioner is responsible for absorbing heat from the indoors and transferring it to the outdoors. If too much of the refrigerant leaks out of the tubing, the system’s pressure will be low. The low pressure of the refrigerant will cause what’s left to get extremely cold. When the warm air passes over the evaporator coil, the moisture will condense and freeze onto the coil. This causes the buildup of frost or ice. Once the air conditioner’s pressure drops too low, the system’s safety switch will prevent it from cycling. Refrigerant leaks should only be fixed by a certified HVAC technician.

Texas Pride is Houston’s trusted provider of air conditioning repairs. We’re also available for heating repairs and heating and air conditioning maintenance and installation. Our service memberships save you money and give you priority service in case of a heating or cooling system breakdown. If you’re a business owner in or near Houston, turn to us for reliable commercial heating and air conditioning services. For more details about why air conditioners freeze up, reach out to us at Texas Pride today.

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