Short answer

There are a few simple, safe things homeowners can check before calling for furnace or AC repair. These checks won’t fix every problem, but they can help identify common issues and prevent unnecessary damage before a technician arrives.

Knowing when to stop checking and call for help is just as important as knowing what to check.

The first thing every homeowner should check

The single most important thing homeowners should check is the air filter.

Dirty filters are the number one cause of HVAC breakdowns. When airflow is restricted, the system cannot operate properly and will often shut itself down to protect internal components.

Checking and replacing a dirty filter can prevent many common issues before they become larger problems.

Safe checks homeowners can do without tools

There are a few basic checks homeowners can safely perform.

These include:

• Checking and replacing the air filter if it is dirty

• Making sure the thermostat is set correctly for the season, heating or cooling

• Checking breakers to see if one has tripped

• Making sure vegetation is cleared away from the outdoor unit so it can breathe properly

These checks are simple, safe, and apply to both heating and cooling systems.

A common mistake homeowners make

A common mistake is replacing a dirty filter and expecting the system to start working immediately.

In many cases, the system needs to be reset at the breaker to clear any safety codes before it will try to start again.

For air conditioning systems, if the indoor coil has frozen due to restricted airflow, replacing the filter is only the first step. The system must be turned off and allowed to fully defrost before trying to run it again. Attempting to run the system while ice is still present will not solve the problem and can make it worse.

When homeowners should stop checking and call for help

Homeowners should stop troubleshooting and call a professional if they see or smell anything burnt.

You should also call if the breaker continues to trip or if the system continues to shut off on its own. An HVAC system should not need to be reset repeatedly to keep running. Repeated shutdowns are a sign that something needs professional attention.

When in doubt, it is always safer to stop and call.

One check that matters year-round

Regardless of the season, airflow always matters.

The system needs to breathe whether it is heating or cooling. A clean filter supports proper airflow in winter and summer and helps prevent many common breakdowns.

What homeowners should never try to do themselves

Homeowners should never try to bypass a safety switch to get a system running.

They should also never attempt to add refrigerant themselves. Refrigerant handling requires proper training, tools, and licensing, and attempting to do this without them can be dangerous and cause serious damage to the system.

If a repair requires accessing gas components, electrical systems, or refrigerant, it’s time to call a professional.

How Bigfoot wants homeowners to use this information

At Bigfoot, we believe education and knowledge help homeowners make informed decisions about their comfort.

Understanding the basics of how your system works allows you to recognize when something is simple and when it’s time to call for help. Our goal is to be a trusted partner who explains what’s happening clearly, without rushing or pressuring you with scare tactics.