The Ultimate HVAC Maintenance Guide for Homeowners

The A-Z of H-V-A-C

The first step of whole-house AC maintenance? Understanding how everything actually works. Let's break it down!

What is an HVAC system?

HVAC stands for Heating, Ventilation, and Air Conditioning. Essentially, it’s a network of systems and components that work together to control the temperature, airflow, and air quality in your home.

How does it work?

There are two main modes to your HVAC system— heating and cooling— and the two function a little differently.

In heating mode, your furnace or heat pump kicks into action. Furnaces burn fuel (like natural gas) to generate heat, which travels through a heat exchanger. A blower fan then circulates that warmth through your ductwork and into your home. Heat pumps work a little differently— they transfer heat from outside (yes, even in the winter!) into your home using refrigerant.

In cooling, it’s a misconception that an AC system "blows cold air.” Actually, it removes heat from your home and sends it outside. Here’s how: refrigerant absorbs heat from indoor air as it passes through the evaporator coils. Then, the compressor moves the refrigerant to the condenser coils outside, where the heat is released. Finally, the cooled refrigerant cycles back inside, and the blower fan pushes cool air through your home.

Types of HVAC systems

Not all HVAC systems are created equal! Depending on your home’s size, layout, and your budget, you might have one of the following:

Central AC and Furnace Systems

This is the most common setup in American homes. A central air conditioner and furnace work together to heat and cool your home using shared ductwork to distribute air.

Ductless Mini-Split Systems

Perfect for homes without ductwork, these systems consist of an outdoor unit connected to indoor air handlers. They’re energy-efficient and allow for room-by-room temperature control.

Heat Pumps

Heat pumps are versatile systems that provide both heating and cooling by transferring heat instead of generating it. They’re ideal for mild climates but can also work well in colder regions with modern advancements.

Hybrid Systems

These combine a traditional furnace with a heat pump, automatically switching between the two for maximum efficiency based on outdoor temperatures.

Window Units

Smaller and more portable, window units are great for individual rooms or apartments but aren’t practical for whole-home cooling.

Additional Reading:

How Air Conditioning Works                    What AC Unit is Right For You
Window AC Vs Central Air                        Ductless Air Conditioner

Why HVAC maintenance matters

Although it’s a little less glamorous on the surface, your HVAC system is a lot like your car— it works hard every day and needs regular checkups to stay in peak condition. Neglecting furnace maintenance can lead to costly repairs, poor performance, and even system failure. Here’s why keeping up with HVAC maintenance is a must:

Energy efficiency

A clean and well-maintained system doesn’t have to work as hard to keep you comfortable. The average home spends $1,900 on energy bills annually, with half of that going to heating costs. Routine maintenance of your HVAC system greatly improves efficiency, saving you money on energy bills.

Extended system lifespan

Want to avoid the headache (and expense) of replacing your HVAC system prematurely? A typical system has a lifespan of 10-15 years. Regular care keeps your system in excellent condition longer, helping you stay on the upper end of that stretch.

Improved air quality

Dust, dirt, and allergens can build up in your system over time, circulating through your home and affecting your air quality. Maintenance keeps the air you breathe cleaner and healthier.

Preventative savings

Many HVAC breakdowns are preventable with regular maintenance. The potential cost to repair or replace your heating system could be up to $5,600, while repairing or replacing your AC system could be up to $6,000. Spending a little time (or money) now on upkeep can save you thousands in unexpected repair bills down the line.*

*Repair/replacement cost is the eightieth percentile as reported in a nationwide survey of homeowners conducted in 2024 by CleaerVantage for American Home Shield.

Peace of mind

There’s nothing worse than your AC quitting on the hottest day of summer or your furnace failing in the middle of a blizzard. Regular furnace maintenance reduces the chances of these stressful, inconvenient breakdowns.

Monthly and seasonal maintenance checklists

Regular maintenance is the key to a long-lasting, efficient HVAC system. Follow this checklist to stay on top of monthly and seasonal tasks.

Essential tools for DIY HVAC maintenance

To keep your HVAC system in tip-top shape, you’ll need a few basic tools. These will make your DIY AC maintenance tasks quicker, easier, and more effective:

• Screwdriver set (5/16" and a 1/4" nut driver)
• Coil cleaning spray
• Soft brush or vacuum attachment (Wet/dry Shop Vac)
• Fin comb
• Garden hose
• Flashlight

Monthly Tasks

When your system seems to be chugging along smoothly, you’re not always worried about maintenance. But there’s a few tasks you should try to do every month:

Inspect and replace air filters:

• Check your air filters for dirt and debris.
• Replace them if they look clogged or dirty. Aim to do this every 1–3 months depending on your system’s usage.

Clean vents and registers:

• Use a vacuum or a soft brush to remove dust and dirt from the air vents.
• Make sure air registers are open and not obstructed by furniture or other objects.

Spring start-up checklist:

As the weather starts heating up, here’s how to approach booting up:

Turn off power:

• Always start by turning off the power to your system at the main switch or breaker box.

Clean the outdoor AC unit:

• Remove leaves, dirt, or any debris from around the outdoor unit to ensure proper airflow.
• Use a garden hose (on a low setting) to rinse off coils top to bottom at a downward angle.

Clear and clean coils:

• Rinse the condenser coils with a water hose and remove dirt or dust build-up.
• Use coil cleaning spray if necessary to help loosen debris.

Check condensate drain line for clogs:

• Check the condensate drain line to ensure water flows freely.
• If you notice clogs, use a wet/dry vacuum to clean the line.

Change dirty filters:

• Replace any dirty or old filters with new ones to maintain proper airflow and air quality.

Vacuum blower motor:

• Carefully vacuum around the blower motor to remove dust and debris that could affect airflow.

Inspect ductwork:

• Check ducts for leaks, cracks, or loose connections. Repair any leaks with duct tape or sealant.

Test the thermostat:

• Set the thermostat to your desired temperature and verify the system kicks on correctly.
• Ensure the thermostat reads the correct temperature to avoid uneven cooling.

Summer AC maintenance tips:

You need your AC to work hard in the summer. Here’s how to maximize its success:

Monitor system performance:

• Check for uneven cooling, particularly in rooms far from the unit, or if certain areas feel warmer than others.
• Listen for unusual noises, such as buzzing, rattling, or humming, which could indicate a problem.

Adjust thermostat settings for efficiency:

• When you’re away from home, raise the temperature to 78°F for cooling to save energy without sacrificing comfort.

Fall shutdown checklist:

As you begin the switch from cooling to heating systems, keep a few checks in mind:

Clean and cover the outdoor unit:

• Clean the outdoor unit thoroughly, removing any debris from the surrounding area.
• Consider covering the unit with a protective cover to prevent leaves and dirt fromentering during the off-season.

Check refrigerant levels:

• Verify that the refrigerant levels are adequate (if you have an EPA refrigerant license; otherwise, call a professional).
• Low refrigerant levels can indicate leaks that need to be addressed by a professional.

Inspect furnace or heat pump:

• Check the furnace or heat pump for signs of wear and tear.
• Look for signs of rust, damage, or loose components that might require attention.

Clean burners and replace filters:

• Clean the burners in your furnace and replace any filters that are dirty or clogged.

Winter furnace maintenance tips:

Winter is coming, and it’s time to prep your heating system to face the chill:

Test heating system early:

• Turn your heating system on before the first cold snap to ensure it’s working properly. This will help avoid a chilly surprise on the coldest days.

Clean vents for obstructions:

• Remove any blockages or obstructions from your heating vents to maintain proper airflow.

Inspect carbon monoxide detectors:

• Test your carbon monoxide detectors to ensure they’re working and replace batteries if needed. A properly functioning carbon monoxide detector is essential for safety during the colder months.

Additional reading:

How to Conduct DIY HVAC Inspection
How to Clean Your Air Conditioner Condensate Drain Line

Troubleshooting common HVAC issues

Even with the best care, things can sometimes go wrong with your HVAC system. Luckily, many common problems are easy to diagnose and fix. Here are some troubleshooting tips to help you get your system back up and running.

Common cooling issues

If you notice that your AC system seems frosty, humid, inefficient, or noisy, it might be a sign that something is up. This is how to troubleshoot some of your most common cooling conundrums:

Not cooling properly:

• Check the thermostat: Make sure it’s set to “cool” and the temperature is set lower than the room temperature.
• Inspect air filters: Clogged filters can reduce airflow and make it harder for your system to cool effectively.
• Examine vents: Ensure air vents are open and unobstructed.
• Outdoor unit: Check for any debris around the outdoor unit that might be blocking airflow.

Frozen coils:

• Turn off the system and let the coils thaw.
• Check for blockages: Look for any obstructions in the air ducts or around the outdoor unit that could be causing reduced airflow.

High humidity levels:

• Replace filters: Dirty filters can hinder airflow and contribute to humidity problems.
• Ensure proper sizing: High humidity is a symptom of an over sized unit, not an undersized system. Make sure the right sized system is installed in your home.

Unusual noises:

• Rattling: This could indicate loose parts inside the system, such as a blower fan or coil. Tighten loose screws or panels, and call a professional if the rattling seems internal.
• Hissing: A refrigerant leak could be the cause of hissing sounds. If you hear this, it’s important to call a professional to check for leaks and re-charge your refrigerant.

Heating issues

If something about your home’s heat feels wrong, it probably is. These are some red flags to look out for and how to resolve them:

Insufficient heat:

• Check thermostat settings: Make sure it’s set to the desired temperature and the heat mode is selected.
• Inspect filters: A clogged filter will reduce airflow and prevent proper heating.
• Check the pilot light or burners: If the pilot light is out or the burners aren’t igniting, you may need to call a technician for repairs.

Unusual smell:

• Check for dirty components: A musty or dusty smell could mean your system’s components need cleaning.
• Gas smell: If you smell gas, turn off your furnace immediately and contact a professional. A gas leak is dangerous and requires immediate attention.

Additional reading:

Frozen AC Unit                         AC Unit Blowing Warm Air
Bad Smells From Air Conditioner         Air Conditioning Lung

Energy efficiency tips for your HVAC system

Want to reduce your energy bills while keeping your home comfortable? Your HVAC system plays a big role in overall energy consumption, so using it wisely can lead to significant savings. Here are some energy-efficient tips to optimize your system’s performance:

Use a programmable or smart thermostat

Program your thermostat to adjust temperatures when you’re not at home or while you’re sleeping. Smart thermostats are inexpensive to install and seamlessly optimize energy use, helping you save about $50-$100 a year on average.

Seal windows and doors

Gaps around windows and doors let hot or cold air escape, forcing your HVAC system to work harder. Seal leaks with weatherstripping or caulk to keep the air where it belongs.

Ensure proper insulation

Insulation helps maintain consistent indoor temperatures by reducing heat loss in the winter and keeping cool air inside in the summer. Make sure your attic, walls, and floors are properly insulated to improve efficiency.

Install ceiling fans

Ceiling fans can help circulate air, making it feel cooler in the summer and more comfortable in the winter. Use fans in conjunction with your HVAC system to improve efficiency.

Shade your outdoor unit

In the summer, place a shade over your outdoor AC unit (but don’t block airflow). This helps the unit operate more efficiently by reducing the heat it absorbs from the sun. Just be sure you’re not obstructing the airflow around the unit.

Maintain regular HVAC servicing

A well-maintained system operates more efficiently. Follow the manufacturer’s guidelines for maintenance and scheduling tune-ups to ensure peak performance throughout the year.

5 Signs it’s time for HVAC system replacement

Even with regular maintenance, all HVAC systems have a lifespan. But how do you know when it’s time to replace your system? Here are some signs that it might be time for an upgrade:

Additional reading:

When to Replace your Air Conditioner             HVAC Replacement Costs
Tips for Buying a New AC Unit

How a home warranty can help

Unexpected HVAC breakdowns can be frustrating, costly, and stressful. But with American Home Shield, you’ll get peace of mind knowing that you have a safety net for those unforeseen repair needs. With American Home Shield coverage and service offerings, keeping your HVAC system in top shape is hassle-free.

American Home Shield home warranty plans offer repair and replacement coverage for major components of your HVAC system, including:

• All covered parts and components of permanently installed air conditioning systems up to a 5-ton capacity
• Condensation lines of ducted central electric split and package units, geothermal units, evaporative coolers, wall air conditioners, and mini-splits
• Upgrades to maintain compatibility and/or compliance with SEER, HSPF, or refrigerant standards if repair or replacement is needed

Member benefits

As much as we love DIY house AC maintenance, there are times when you should leave it to the Pros. Thanks to AHS member benefits, you never have to tackle HVAC maintenance alone. With select plans, members get:

• HVAC tune-ups: Professional HVAC servicing is available in the spring and fall for just $100 per unit with our ShieldSilver™, ShieldGold™ plans. One free tune-up per contract term is included in the ShieldPlatinum™ plan.
• New HVAC System Program: Leverage our national buying power to save thousands off national retail pricing on a new HVAC system. This upgrade includes a free, at-home assessment, options tailored to your home’s specific needs, and installation from a trusted HVAC Pro.
• Real-time Expert video chats: With American Home Shield video chat, you can connect with a live repair Expert to help you assess or fix home HVAC* hassles. This benefit is available for AHS members with ShieldGold™, ShieldPlatinum™, ShieldPlus℠, and ShieldComplete℠ plans at no extra cost. See AHS.com for hours and details.

*HVAC system tune-ups are offered by Frontdoor Pro and performed by a FrontdoorPro® independent service contractor. For Frontdoor Pro license numbers, please visit Frontdoor Pro Licensing Information. HVAC service dates are limited and may vary based on location.

Additional reading:

Home Warranty for an AC Unit
Is AC Ductwork Covered by a Home Warranty
When to Book an Air Conditioning Service Appointment
HVAC Service Requests and Upgrade Program

AHS assumes no responsibility, and specifically disclaims all liability, for your use of any and all information contained herein.