How To Diagnose and Solve Your Outdoor AC Unit Problems

Central air conditioners feature an outdoor unit that houses the compressor and condenser. This unit is usually placed on a concrete pad that is located near the house. If the outdoor unit isn't working properly, then your AC will be unable to cool your home as desired. 

Here’s how to diagnose what’s wrong with your AC, and what you can do about it.

Problem Symptoms

Ideally, you’ll notice any issues before the unit breaks down entirely, when repairs are often easier and less expensive to make. 

Weak Airflow

Air flow from the vents inside the house will often become weaker in force or warmer in temperature when a problem begins to surface in the outdoor unit. The issue could be poor cooling by the condenser, or issues with the fan and blower assembly that are reducing air flow.

Odd Noises

The outdoor unit isn't perfectly silent—it will hum and vibrate lightly when it is running. The problem is noises that are more abrupt or invasive, such as banging, heavy shaking, or squealing sounds. These often indicate that there is a mechanical problem somewhere in the unit. 

Operation Failure

Operation failure can range from units with fans still rotating but no cool air production, to those that fail to come on entirely. Mechanical issues or a lack of power to the unit are usually the cause of such catastrophic failure.

Common Causes

Knowing the problem can help guide one to the cause, but it helps to know the most common issues that specifically cause trouble with the outdoor AC unit. 

Condensate Failure

Your outdoor unit is equipped with a condensate system designed to route moisture from condensation away from the unit. This includes a pump to move the water, a catchment tray, and water lines. Pump failure or line clogs can trigger a shutdown of the unit, a safety feature that is meant to prevent further problems.

Dirt Buildup

Dirt and debris can get into an outdoor unit and cause blowers to bind up quite easily, especially if there are plants crowding the unit or overhead tree branches dropping leaves upon it. There doesn't have to be large debris for there to be problems, either. Sometimes dirt and grime can collect on the outdoor coil fins, which will inhibit the AC's ability to cool.

Mechanical Failure

Mechanical failure can range from electrical problems, such as worn wiring or an issue with the breaker, to problems like a broken fan blade or failed blower motor. Issues like broken fan belts or failed anti-vibration systems are also considered mechanical problems. 

Prevention & Repair

Prevention is preferred over repair, but the good news is that repair is often possible so you may not need to replace a malfunctioning AC unit. 

Periodic Cleaning

One of the best ways to keep your outdoor unit working well is to clean it out periodically. The housing of the unit is easily removed so that leaves and other debris can be vacuumed out with a shop vac or removed by hand. The fins will also require hosing off, but care must be taken not to bend or damage them as this can affect operation.

Landscape Maintenance

Maintaining the landscaping around your AC is a must if you want to keep debris out and prevent air circulation issues. Generally, it's a good idea to keep grass and other plants pruned back at least 2 feet around the unit. 

Annual Inspection

An annual inspection and tune-up both prevents problems and catches developing issues so they can be repaired. Your maintenance tech will clean out the unit, replace any damaged belts, and lubricate all moving parts. Damaged parts—like a fan blade or old anti-vibration pads—can be replaced. The fins can be straightened with a special tool if necessary. 

Contact Briarwood Heating & Cooling if you suspect that your outdoor unit isn't working properly.