Air Handler Troubleshooting: Fan, Control Board, and Airflow Issues

Weak airflow from your vents, pooling water around the indoor air handler, and grinding noises are some of the most common symptoms you may notice if your air handler isn’t working properly. By learning a few air handler troubleshooting tips, you can fix basic issues. If these tips aren’t enough, scheduling a professional heating, ventilation, and air conditioning (HVAC) inspection can help you detect the underlying issue. If your air handler isn’t working properly, scheduling professional HVAC repair early can help prevent more extensive damage.

What Is an Air Handler and What Does It Do?

An air handler is the indoor unit in your HVAC system. It is responsible for transferring conditioned air throughout your home. Indoor air is brought into your HVAC system, conditioned, and released at the appropriate temperature.

The indoor air handler includes key components, such as the blower motor, evaporator coil, condensate drain line, and air filter. While the blower motor is necessary to push air into your ductwork, the evaporator coil absorbs heat from the air so it can be released outside. The air filter removes contaminants from the air so they don’t enter your HVAC system. Meanwhile, the condensate drain line and drain pan collect and transfer water away from your home. Restricted airflow can also affect comfort and indoor air quality, making routine HVAC maintenance even more important.

Common Signs Your Air Handler Isn’t Working Properly

If your air handler isn’t working properly, you may notice some of the following symptoms

• Weak or no airflow
• Odd noises
• A blower fan won’t turn on
• Burning or electrical smells
• Uneven temperatures in different areas of your home
• Frequent system shutdowns
• Warm air blowing from the vents

Why Does My Electricity Keep Tripping When the HVAC System Runs?

So, why does my electricity keep tripping? If it seems like your electricity trips whenever the HVAC system turns on, it could be due to a few different problems.

• Dirty blower motor 
• Short circuits and damaged wiring
• Blower motor failure
• Failing capacitors
• Control board failure

Your breaker panel is designed to safely distribute power throughout your home. If a circuit draws more power than the breaker can safely handle, it will trip. For example, a dirty blower motor or failing capacitor can draw an excessive amount of power.

Do not keep resetting the breaker if the HVAC breaker keeps tripping. Frequent tripping means there is an underlying electrical or mechanical problem. To avoid a potential fire hazard and damage to your unit, you should get the issue fixed instead of resetting the breaker repeatedly.

Fan Problems That Affect Air Handler Performance

If your air handler fan is not working, it can affect your air handler’s performance. For example, a failed blower motor and worn blower bearings can reduce the amount of air that reaches each room. Similarly, a dirty blower assembly or loose blower wheel can cause similar symptoms. If the blower motor or fan components fail, professional AC repair and maintenance can restore proper airflow.

Capacitor-related issues can also impact your fan’s operations. The capacitor normally helps the blower motor to start. If the capacitor isn’t working properly, the blower motor won’t be able to push air into your ductwork. 

Control Board Problems

The air handler control board is like the brain of your HVAC unit. It relays signals from the thermostat to the rest of the unit. Normal wear, power surges, and electrical damage can harm the control board and cause it to stop working properly. If this happens, you’ll likely notice that your HVAC system cycles erratically or doesn’t start. It may also be unresponsive to commands, exhibit signs of physical damage, or produce unusual clicking noises. Control board issues often require professional furnace repair and maintenance to safely diagnose electrical problems.

A control board malfunction isn’t something you can fix on your own. These boards handle dangerously high voltage, which poses an electric shock and fire risk. Additionally, furnaces use gas valves and hot igniters, so there is an added risk of a gas leak or fire hazard posed if the control board is miswired.

Airflow Problems That Reduce HVAC Performance

If the airflow in your HVAC system is obstructed, it can directly impact your overall performance. Clogged HVAC filters, blocked supply or return vents, and damaged ductwork can directly limit airflow into your HVAC system. Similarly, dirty or frozen evaporator coils can restrict airflow and the transfer of heat. You may also experience airflow issues if the blower speed isn’t set properly.

Safe Troubleshooting Steps Homeowners Can Try

As a homeowner, you can try the following air handler troubleshooting on your own. If these steps do not work, you’ll need to reach out to one of our HVAC professionals for a more comprehensive evaluation and air handler repairs.

1. Check Thermostat Settings: Sometimes, a family member will change the temperature or switch the unit to fan-only mode and forget to change the settings back. Verify that the thermostat is set to the right temperature and mode. 
2. Replace the HVAC Air Filter: A dirty HVAC filter can limit airflow, resulting in a frozen coil and poor performance. Ideally, the filter should be replaced every 30 to 90 days, depending on the manufacturer. During periods of peak usage, it will need to be replaced more frequently.
3. Inspect Supply and Return Vents: Check your vents to make sure they are open. Remove any furniture, curtains, clothes, or other belongings that may be blocking them.
4. Check the Circuit Breaker: A tripped breaker can cut off power to your HVAC system. Reset the breaker once if it has tripped. If the breaker keeps tripping, stop using the HVAC system and schedule professional repairs.
5. Listen for Unusual Sounds: Certain noises indicate different types of problems, making the diagnostic process easier.
6. Inspect the Outdoor Unit: Check the outdoor unit for unusual noises and other issues. For example, plants and debris should be removed from within 2 to 3 feet of the outdoor unit to ensure proper airflow.
7. Reset the Thermostat: If the thermostat is malfunctioning, you can try resetting it. For thermostats that aren’t hardwired in, you can try replacing the batteries.
8. Know Which Repairs Should Never Be Attempted Yourself: For the safety of your home, family, and HVAC equipment, you should never attempt any repair that involves refrigerants, electrical components, or mechanical repairs.

When To Call an HVAC Professional

If you experience any of the following situations, it’s time to reach out for professional HVAC repairs in Eugene, OR.

• You noticed a burning odor.
• The breaker keeps tripping.
• Your HVAC system doesn’t heat or cool your home properly.
• The airflow in your ductwork is weak, even after you have replaced the filter.
• Your blower fan won’t start.
• The HVAC system shuts down repeatedly.
• Your control board appears to be damaged.

Repair vs. Replace: What Makes Sense?

As part of our air handler and blower motor troubleshooting, we’ll help you determine if repairs or replacement is the best option based on a few essential considerations.

Repair Cost

The cost and extent of repairs play an important role in deciding whether to repair or replace your air handler. Minor issues may be worth fixing, while frequent or costly repairs may indicate that replacement is a better long-term option. An HVAC professional can evaluate your system and recommend the most practical solution. Replacing filters regularly is one of the most important steps in an AC maintenance checklist.

Age

When you have an aging air handler, a replacement is often the best way to go. Older units are more likely to have more frequent repairs and higher energy costs, making a replacement a more cost-effective long-term decision.

Condition

The unit’s condition is also a factor. If the unit is relatively young but has a history of requiring frequent, costly repairs, it may be time for a new one.

Comfort

If your HVAC performance is starting to decline or your energy bills have spiked inexplicably, it may be time for a replacement.

Preventing Future Air Handler Problems

To avoid problems in the future, remember to use the following maintenance tips.

• Scheduling an annual HVAC maintenance program can help prevent unexpected breakdowns.
• Change air filters every 30 to 90 days, depending on the manufacturer.
• Clear any obstructions that are blocking the vents.
• Immediately address airflow problems when they occur.
• Visually inspect during your routine maintenance work, but do not fix them yourself. If you notice an issue, call one of our HVAC technicians to repair it.
• Get your HVAC system ready before peak heat and cooling season arrives.

Why HVAC Electrical Problems Should Never Be Ignored

If you experience repeated HVAC electrical problems, you should immediately call for professional diagnostics. Electrical malfunctions can end up damaging costly electrical components and causing electric shocks. Because of overheating, faulty electrical systems can cause fires. 

You should never repeatedly reset a tripped breaker. Repeated tripping means there is an underlying issue. Left untreated, this problem can cause a fire or electrical hazard.

Professional diagnostics save you money by preventing expensive damage and future repairs. By ensuring your system functions at its best, our diagnostics and repairs can also lower your energy bills each month.

Why Homeowners in Eugene & Springfield Trust Priority One Heating & Air Conditioning

Local homeowners turn to Priority One because of our experienced HVAC repair technicians and accurate diagnostics. We are committed to providing honest repair recommendations and upfront pricing. From our preventative maintenance expertise to fast services, Eugene and Springfield homeowners count on us to deliver reliable HVAC support.

Frequently Asked Questions About Air Handlers

What does an air handler do?

The air handler is basically the indoor portion of your HVAC system. It is responsible for moving conditioned air throughout your home with the help of the blower motor, ductwork, and other components.

Why is my air handler not blowing air?

Air handler airflow issues can occur due to a clogged air filter, incorrect thermostat settings, a faulty blower motor, a tripped breaker, or a clogged condensate drain line. As a homeowner, you can replace the air filter, check the breaker, and verify that the drain line is unobstructed. For other problems, you’ll need to reach out for professional air handler troubleshooting.

Can a dirty filter stop an air handler from working?

Yes, it can. At the very least, a clogged air filter can cause the air handler to work less efficiently. A dirty filter can block airflow, causing the blower motor to overheat and shut down. During the cooling mode, a lack of airflow can cause the evaporator coil to freeze as well.

Why does my HVAC system keep tripping the breaker?

Your HVAC system will keep tripping if there is an ongoing electrical or mechanical problem. For example, an overheated blower motor can trip the breaker. Similarly, a faulty capacitor and dirty condenser coils can draw too much power from your electrical system, and restricted airflow, dirty blower assemblies, failing capacitors, or compressor issues may overload the electrical circuit.

How do I know if my blower motor is bad?

If your HVAC blower is not working, it can immediately affect the airflow in your home. Besides noticing reduced airflow from your vents, you may also notice a burning odor and grinding or squealing sounds.

Can a bad control board stop my HVAC system?

Absolutely. As the brain of your HVAC system, the control board is responsible for relaying your thermostat’s signals to the rest of your system. If it isn’t working, these messages cannot be sent or received.

Schedule an HVAC Inspection Today

If basic air handler troubleshooting doesn’t solve the problem, reach out to Priority One for a professional HVAC inspection and air handler diagnostics. From electrical troubleshooting to blower motor repairs, we can quickly resolve your air handler issues.

Don’t ignore weak airflow, repeated breaker trips, or blower problems. Schedule professional air handler diagnostics with Priority One today.