Commercial Rooftop AC Troubleshooting Guide for Tacoma & Surrounding Areas

If your Tacoma business runs on a rooftop AC unit, it probably stays out of sight and out of mind. But when your system stops working on a hot Pacific Northwest summer afternoon, your customers, staff, and inventory can quickly feel the heat. In this rooftop unit repair guide, we’ll walk you through the troubleshooting steps to take when your system stops working and signs it’s time to call our experts for commercial rooftop unit repair in Tacoma.

How Commercial Rooftop AC Units Work

Most commercial buildings in Tacoma are cooled by rooftop air conditioners to provide consistent indoor comfort for staff, customers, and inventory. Instead of a split indoor-outdoor set-up like most home systems, rooftop units are a single package that contains the compressor, coils, blower, and controls all in one.

These systems pull warm air from inside, pass it over a cold evaporator coil to remove heat, and send cool air back into your ductwork. Keeping the system on the roof helps to free up floor space and keeps noise away from work areas. But with Tacoma’s wet winters and rising summer temperatures, the climate can take a toll on your system as it lives fully exposed to the weather.

Common Signs Your Rooftop AC Needs Attention

Because your rooftop AC is out of sight, your first warning signs will often show up inside your building. If you notice any of the following, it’s likely time to schedule commercial air conditioning service:

• Warm air blowing from the vents while the AC is running.
• Rooms that feel significantly warmer or cooler than others.
• Little to no air is coming through the vents.
• A sudden, unexplained jump in your energy bill.
• Grinding, rattling, or buzzing noises.
• Constant on and off cycles, without rooms ever reaching the right temperature.

Top Commercial Rooftop AC Problems

Dirty coils and air filters

Clogged air filters and dirty coils are one of the most common commercial HVAC problems. Because rooftop units sit exposed to the elements, they collect dust, pollen, leaves, and moss on the coils and inside the filter. Without regular changes and coil cleanings, these buildups can cause your system to run longer, use more energy, and limit airflow throughout your building.

Refrigerant leaks

Refrigerant carries heat out of your building and releases it outdoors. When a worn-out fitting, coil, or pinhole in the line allows refrigerant to leak out, your system’s compressor starts to overwork and wear out faster. You’ll often notice your rooftop AC not cooling, ice on the lines or coils, and a strange hissing sound coming from the unit.

Electrical Component Failures

Your rooftop AC runs on contactors, capacitors, relays, control boards, and wiring that are constantly vibrating or cycling when your unit’s in use. When one of these electrical components wears out, corrodes, or fails, it can prevent the compressor and fan from starting or cause the system to cycle repeatedly. Electrical failures often prevent your system from starting up, trip your circuit breakers, or cause a sudden shutdown in the middle of a heat wave.

Thermostat or Control System Problems

Sometimes the issue lies within your AC controls, rather than the equipment itself. Miscalibrated thermostats, dead batteries, faulty sensors, or failing control boards can cause your AC to short-cycle, run nonstop, or never reach the set temperature. Checking that all of the controls are working properly can help rule out deeper problems with your system.

Drainage and Moisture Issues

When your rooftop unit cools the air, it pulls moisture that drains through a condensate pan and line. If the line clogs with algae, debris, or rust, water can back up into your unit and cause electrical shorts, mold growth, and leaks.

Why Preventative Maintenance Matters for Commercial Rooftop Units

Thankfully, most rooftop AC unit issues are preventable with regular maintenance. Scheduling seasonal tune-ups keeps coils and filters clean, drain lines clear, and components in working order. Regular inspections also help spot hidden problems at the start, before they turn into major breakdowns that leave your staff and customers sweating in the Pacific Northwest summer heat. With routine rooftop unit maintenance, you’ll help your unit run more efficiently, prevent unexpected repairs, extend its lifespan, and protect your bottom line.

When to Call a Commercial HVAC Professional

If you start spotting the warning signs that something’s wrong with your rooftop air conditioner, contact a trusted HVAC company like Kliemann Brothers as soon as possible. Working with rooftop units means heights, high-voltage power, and regulated refrigerant, so it’s always best to leave the work to a trained professional.

HVAC technicians can thoroughly inspect your system, locate the source of your cooling issues, and recommend the right solution to restore cooling to your building. Whether it’s an air filter change, failing compressor, or electrical malfunction, they have the tools and expertise to handle the repair and keep your staff, customers, and inventory at a comfortable temperature.

Commercial HVAC Challenges in Tacoma & Pierce County

Having a rooftop air conditioner in Pierce County means your unit is constantly exposed to salty air, rainy days, and seasonal wildfire smoke. Some of the top challenges in Tacoma that can affect your AC include:

• Marine air: Salty air from the nearby Puget Sound can speed up corrosion on cabinets, coils, and electrical connections.
• Hot summers: Long stretches of summer heat can put added wear on commercial systems, causing them to run longer and break down when you need them most.
• Wildfire smoke: Smoky air in the late summer can cause AC air filters to clog faster than usual, straining your system and lowering your indoor air quality.
• Rainy season: Months of rain can leave standing water, moss, and leaf debris on your rooftop unit, blocking drainage and causing components to rust over time.

How Kliemann Bros Helps Tacoma Businesses Stay Cool

Since 1998, our family-owned HVAC company has been helping South Puget Sound businesses stay cool with expert rooftop HVAC service in Tacoma. We understand how the area’s salt air, heat waves, and smoke can wear on the equipment on your roof, and provide honest recommendations and lasting solutions that hold up to the Pacific Northwest climate.

Our NATE-certified technicians handle HVAC troubleshooting, repairs, replacements, and ongoing maintenance for businesses, so you have peace of mind knowing your AC is ready to keep up when the next heat wave rolls in. When you need commercial HVAC repair near you, call our team for service you can trust.