HVAC Troubleshooting Guide: What To Check When Your AC Isn’t Working

When temperatures start to spike in Bend and Redmond, you can’t afford to have your air conditioner malfunction. Heating, ventilation, and air conditioning (HVAC) systems tend to malfunction when they are being used intensively, making heat wave breakdowns more likely. With the right HVAC troubleshooting, you can quickly determine the cause and find a workable solution.  If basic troubleshooting doesn’t help, Central Oregon Heating, Cooling, Plumbing & Electrical can perform a full AC evaluation.

How Your Air Conditioning System Works

During a basic cooling cycle, refrigerant in the evaporator coil absorbs heat. This heat is cycled outdoors, where the compressor compresses the refrigerant into a high-pressure, high-temperature vapor. The refrigerant then condenses into a high-pressure liquid inside the condenser coil. Then, the condenser fan pulls outdoor air across the condenser coil, allowing heat to transfer from the refrigerant.

Inside your home, the blower fan and a network of ducts are necessary for transferring conditioned air throughout your home. Your thermostat and control board work together to signal this entire process to start. If any single component in this entire system fails, it can immediately affect your AC performance.

Start With These Quick Checks Before Calling for Service

Before you call for professional repairs, there are a few HVAC troubleshooting tips you can use to resolve the issue.

1. Verify the Thermostat Settings: See if the thermostat is set to the correct mode and temperature.
2. Check the Circuit Breaker: A tripped breaker is a common reason for an air conditioner not working. You can reset it once. If it keeps tripping, you’ll need a professional evaluation.
3. Replace or Inspect the Air Filter: Air filters should be replaced every 30 to 90 days. If the filter gets too dirty, it can reduce airflow and lead to a frozen evaporator coil.
4. Make Sure All Supply and Return Vents Are Open: Blocked or closed vents can limit airflow. Open the vents and remove anything that may be obstructing them.
5. Inspect the Outdoor Condenser for Debris: Remove any plants or debris that are within 2 to 3 feet of the outdoor unit. Once the AC is off, you can also use a garden hose to gently rinse the fins.
6. Check Whether the Disconnect Switch Is On: If the outdoor disconnect switch has been switched off, your AC will only blow warm air.

Common Reasons Your AC Isn’t Working

So, why is my AC not working? While many problems could be at fault, the following are some of the most common reasons why an AC will stop functioning properly.

• Dirty air filters
• Low refrigerant levels
• Thermostat malfunctions
• Tripped circuit breakers
• Compressor failure
• Dirty condenser coils
• Condenser fan motor failure
• Frozen evaporator coils
• Failing capacitors
• Clogged drain lines
• Control board malfunctions
• Float switch issues
• Electrical problems

If your system continues experiencing any of these problems after basic troubleshooting, our AC repair services in Bend and Redmond can identify the underlying cause before it leads to more extensive damage.

What Different AC Symptoms Usually Mean

Each AC problem causes different symptoms. By understanding what each symptom means, you can quickly narrow down the list of possible causes.

• AC Won’t Turn On: This can occur if there is a tripped breaker, thermostat malfunction, control board issue, faulty capacitor, or clogged drain line.
• AC Runs but Doesn’t Cool: You may notice this symptom if there is a frozen coil or the outdoor unit’s breaker has tripped. Dirty air filters and low refrigerant levels can also lead to this symptom. For a more detailed breakdown of possible causes, read our guide on why your AC isn’t blowing cold air.
• Weak Airflow From Vents: Weak airflow can stem from damaged ductwork, faulty blower motors, blocked vents, or dirty air filters.
• Warm Air Coming From Vents: When vents only blow warm air, it may be due to a frozen AC coil, a clogged air filter, or incorrect thermostat settings. This can also occur if the outdoor unit’s breaker has tripped.
• AC Keeps Turning On and Off: If your AC short cycles, you may have an oversized unit, a dirty air filter, low refrigerant levels, or electrical malfunctions. Overly narrow temperature settings can also cause this problem.
• Ice Forming on the System: You may experience this issue if the AC has a dirty evaporator coil, low refrigerant levels, or a clogged filter.
• Water Leaking Around the Indoor Unit: Water leaks are generally due to a clogged condensate drain line or frozen AC coil.
• Strange Noises: Unusual noises can stem from many different problems. For example, hissing may indicate a refrigerant leak, while a grinding noise can indicate worn-out bearings. Grinding, buzzing, squealing, and banging noises often point to different mechanical problems. Learn more in Why Is My AC So Loud? Common Noises and What They Mean.
• Burning Smells: If you notice a burning smell, you should immediately shut off the unit because electrical issues pose a fire hazard.
• High Energy Bills: Any problem that causes the AC to run longer can lead to higher energy bills. For example, dirty air filters, frozen AC coils, and low refrigerant can all result in higher electricity costs.

Safe Troubleshooting Steps Homeowners Can Perform

As a homeowner, there are a few things you can safely do to solve an AC issue. If the following AC troubleshooting guide doesn’t work, you’ll need to seek professional help.

• Reset the Thermostat: Then, verify that it is set to the correct mode and temperature.
• Replace the HVAC Filter: At a minimum, this should be done every 30 to 90 days.
• Clear Away Debris: There should be 2 to 3 feet of clearance around the outdoor unit.
• Check the Vents and Registers: Verify that they are open and unobstructed.
• Reset the Breaker Once: However, only reset it once. Repeatedly tripped breakers mean that something else is wrong.
• Look for Ice Buildup: If the coil is frozen, you’ll need a professional HVAC technician to determine the cause. Turn the cooling system off and allow the coil to thaw before scheduling service.
• Listen for Unusual Sounds: These noises will help you diagnose what is going on with the unit.
• Record Any Error Codes: HVAC units give off error codes if there is a problem to indicate what is wrong.
• Know When To Stop Troubleshooting and Call for Help: If this basic HVAC troubleshooting doesn’t solve the issue, you’ll need to schedule professional AC repairs.

When You Should Turn the System Off Immediately

You should immediately turn off your AC if you notice any of the following symptoms.

• Burning odors
• Frequently tripped breakers
• Loud grinding, banging, or buzzing noises
• Frozen evaporator coil
• Water near electrical components

Why DIY Repairs Can Make HVAC Problems Worse

Performing DIY repairs incorrectly can void your warranty and lead to more expensive repairs in the future. Additionally, electrical and refrigerant-related repairs should never be handled by homeowners. If troubleshooting doesn’t solve the problem, it’s safest to schedule professional AC repair rather than attempting electrical or refrigerant repairs yourself.

AC Problems That Require Professional Repair

While you can handle some central air troubleshooting on your own, the following issues should only be dealt with by a trained professional. Our air conditioning repair experts diagnose refrigerant leaks, compressor failures, electrical problems, and airflow issues using professional testing equipment.

• Compressor issues
• Condenser fan motor problems
• Refrigerant leaks
• Faulty control boards
• Blower motor repairs
• Electrical issues
• Capacitor replacements

Repair vs. Replace: How To Decide

After our HVAC troubleshooting, we’ll help you decide whether to repair or replace the unit. If the unit is older or requires frequent repairs, a replacement may be the better choice. Additionally, increased energy bills are often a sign that the unit’s performance is starting to decline. In comparison, AC repairs are a good option if the repairs are relatively inexpensive, the system is still new, and the unit has required minimal repairs in the past. If you’re unsure whether repairing or replacing your system makes more financial sense, read When To Replace Your AC in Central Oregon. 

How Preventative Maintenance Helps Avoid AC Breakdowns

To avoid future AC problems, one of the most important things you can do is perform preventative maintenance. Scheduling routine AC maintenance each spring is one of the best ways to prevent expensive breakdowns. You can also learn about The Real Cost of Ignoring HVAC Maintenance and why regular service saves money over time. To keep your system functioning at its best, our team can clean the condenser coils and check refrigerant levels. In between tune-ups, regular filter changes are necessary to keep your AC running as efficiently as possible.

Why AC Problems Often Increase During Central Oregon Summers

During summertime in Central Oregon, our high afternoon temperatures, dust accumulation, and increased cooling demand place an added strain on the units. The seasonal wear on aging systems increases the likelihood of a breakdown. Because of this, one of the most important things you can do to prevent summertime breakdowns is to schedule a routine maintenance appointment each spring. 

Why Homeowners in Bend & Redmond Trust Central Oregon Heating, Cooling, Plumbing & Electrical

When it comes to AC repairs in Redmond, OR, local homeowners trust Central Oregon with their HVAC services for a few key reasons.

• Experienced Technicians: Our technicians work with all makes and models of HVAC equipment.
• Comprehensive System Diagnostics: Through our full evaluations, you can quickly discover the root cause of your AC issue.
• Honest Recommendations: As your trusted advisors, we are committed to providing honest, no-pressure recommendations.
• Fast Response Times: When disaster strikes, our team is ready with 24/7 repair services.
• Local Knowledge: Our team understands what Central Oregon homeowners need from their HVAC systems.

Frequently Asked Questions About AC Troubleshooting

Why won’t my AC turn on?

If your AC won’t turn on, it may be due to incorrect thermostat settings, a tripped breaker, or a faulty capacitor. Clogged drain lines and frozen AC coils can trigger safety shutdowns. You can troubleshoot by replacing the air filter, checking the thermostat settings, resetting the breaker, and clearing the drain line. If these troubleshooting steps don’t resolve the issue, you’ll need to reach out for professional help.

Why is my AC blowing warm air?

Low refrigerant levels and dirty air filters can cause the AC to struggle, leading to warm airflow. Many ACs are set up with separate breakers for the indoor and outdoor units. If the outdoor unit’s breaker trips, it can also cause warm airflow. Additionally, incorrect thermostat settings can lead to an AC blowing warm air.

Why does my AC keep tripping the breaker?

Breakers trip due to circuit overloads, short circuits, and ground faults. If the AC breaker keeps tripping, it’s likely because an electrical or mechanical issue is causing the AC to pull too much power. For example, this can happen because of a failing capacitor, damaged wiring, damaged compressors, dirty air filters, or blocked outdoor condenser units. Because of the potential danger to yourself and your HVAC system, you should immediately shut off the AC if it keeps tripping the breaker.

Can a dirty filter stop my AC from working?

Yes, it can. A dirty filter restricts airflow, which can lead to a frozen evaporator coil, reduced system performance, and possible compressor damage. Besides causing premature repairs, the decreased efficiency can result in higher energy bills.

Why is my AC running but not cooling?

If your AC is not cooling, it may be due to the wrong thermostat settings, a frozen AC coil, a dirty filter, or a tripped breaker. For instance, frozen coils hinder the absorption of heat, leading to warmer airflow. Fortunately, you can troubleshoot by replacing the air filter, checking the thermostat settings, and resetting the breaker. If these steps don’t work or the breaker trips again, you’ll need to schedule professional repairs.

When should I repair versus replace my air conditioner?

The decision to repair or replace should be based on the cost of the repairs, the age of your unit, energy-efficiency changes, and the AC’s performance. If the AC is approaching the end of its life, has performance issues, and requires frequent repairs, a replacement is generally a better option. Similarly, sudden spikes in your monthly energy bill may mean that your AC’s performance is starting to decline.

How often should my AC be serviced?

We recommend scheduling a routine tune-up each spring before the weather warms up. Maintenance appointments are essential for detecting and preventing hidden AC problems from causing a total HVAC failure.

Schedule Your AC Inspection Today

If basic HVAC troubleshooting doesn’t resolve your AC problem, our team is here to help. We provide fast diagnostics, emergency repairs, and scheduled AC repair service throughout Bend, Redmond, and surrounding Central Oregon communities. Schedule your AC inspection before a small issue becomes an expensive repair.