Introduction: The Critical First Steps to Reliable HVAC Comfort
For new homeowners, moving into a freshly purchased property is both exciting and daunting. Amidst unpacking boxes and hanging pictures, one essential system often gets less attention than it deserves: your HVAC. Whether you’re overseeing a brand-new installation or replacing an aging system, the process is rife with potential pitfalls. HVAC systems are complex, and even seemingly minor mistakes during installation can lead to long-term headaches—including poor indoor air quality, soaring energy bills, chronic breakdowns, and even safety hazards.
This in-depth guide unpacks the most common HVAC installation mistakes made by new homeowners. Drawing from real-world contractor experiences and industry best practices, we’ll help you recognize red flags, ask the right questions, and make informed decisions. You’ll learn how to spot improper sizing, avoid ductwork disasters, navigate compliance requirements, and ensure your investment delivers comfort, efficiency, and reliability for years to come.
If you’re a first-time buyer, a seasoned homeowner taking on a major upgrade, or a property manager overseeing installations, these insights will arm you with the practical knowledge needed to sidestep costly errors and maximize your HVAC system’s performance.
Understanding the Basics: What Makes a Good HVAC Installation?
The Components of a Reliable System
Before diving into mistakes, let’s outline what a top-tier HVAC installation looks like. A properly installed system should:
- Deliver consistent, even comfort throughout the home
- Operate quietly and efficiently
- Promote healthy indoor air quality
- Comply with local building and safety codes
- Be accessible for maintenance and filter changes
Key Factors for Success
- Correct System Sizing: Ensures efficiency and comfort
- Well-Sealed, Balanced Ductwork: Prevents leaks and uneven airflow
- Professional Installation: Guarantees code compliance and warranty protection
- Quality Components: Reduces risk of early failure and service calls
- Proper Location: Optimizes performance and minimizes noise
If any of these fundamentals are overlooked, problems can multiply quickly.
Top HVAC Installation Mistakes Made by New Homeowners
1. Skipping Proper System Sizing
One of the most frequent—and costly—errors is assuming “bigger is better” or simply replacing the old unit with the same size as before. HVAC sizing isn’t about matching square footage alone; it requires a Manual J Load Calculation that considers insulation, window types, air leakage, sun exposure, and occupancy.
- Oversized Systems: Short cycle, leading to excess wear, uneven temperatures, and poor humidity control.
- Undersized Systems: Struggle to maintain comfort, run constantly, and suffer premature breakdowns.
How to Avoid: Insist on a Manual J calculation from your contractor. If they skip this step, it’s a red flag.
2. Neglecting Ductwork Design and Condition
Ducts are the lifeblood of your HVAC system. Yet many homeowners focus solely on the furnace or AC, ignoring whether the existing ductwork is right for the new system.
- Poorly Sized Ducts: Restrict airflow, causing noise and reduced efficiency.
- Leaky or Uninsulated Ducts: Waste energy and introduce contaminants.
- Improper Layout: Results in hot/cold spots and increased utility bills.
How to Avoid: Request a ductwork inspection and, if needed, a redesign. Modern systems often require different airflow than older ones.
3. Overlooking Ventilation and Fresh Air Needs
With energy-efficient, tightly sealed homes, proper ventilation is crucial. New homeowners sometimes forget to include mechanical ventilation—such as ERVs (Energy Recovery Ventilators) or HRVs (Heat Recovery Ventilators)—to replace stale indoor air with fresh outdoor air without sacrificing efficiency.
How to Avoid: Discuss fresh air ventilation options with your installer, especially if your home is recently built or has undergone significant air sealing.
4. Failing to Plan for Filter Accessibility
Air filters must be changed regularly for both air quality and system health. Installers sometimes place filters in hard-to-reach locations (e.g., tight crawlspaces or behind heavy panels), discouraging maintenance.
How to Avoid: During installation planning, ask to see exactly where the filter is located and ensure it’s easily accessible for routine changes.
5. Ignoring Local Codes, Permits, and Inspections
Skipping required permits or not scheduling final inspections is a surprisingly common pitfall. This can void warranties, cause insurance issues, or even result in fines and forced rework if a problem is discovered later.
How to Avoid: Always verify that your contractor is pulling permits and arranging inspections. Keep documentation for your records.
6. Placing Outdoor Units in Poor Locations
The condenser or heat pump outside needs breathing room and should be placed away from bedrooms, windows, and debris sources.
- Too Close to Walls or Fences: Restricts airflow, reducing efficiency and lifespan.
- Under Drip Lines or Trees: Increases risk of clogging and corrosion.
- Near Bedrooms: May transmit unwanted noise.
How to Avoid: Walk the site with your installer and discuss placement. Check manufacturer clearance requirements.
7. Skimping on Insulation and Air Sealing
Even the best HVAC system can’t compensate for a drafty, poorly insulated home. Some homeowners invest in high-efficiency equipment but ignore the building envelope, leading to persistent comfort and efficiency complaints.
How to Avoid: Consider a home energy audit. Address insulation and air sealing before sizing and installing your new system.
8. Not Verifying Refrigerant Charging and Airflow on Startup
Improper refrigerant charge or airflow issues during system commissioning can cause inefficiency and shorten equipment life. This step is sometimes rushed or skipped entirely.
How to Avoid: Ask for documented commissioning reports showing correct refrigerant levels and airflow readings.
9. Forgoing a Detailed Written Proposal
Verbal agreements or vague quotes often lead to miscommunication and unmet expectations.
How to Avoid: Insist on a detailed, itemized proposal listing equipment models, scope of work, warranty terms, and any exclusions.
10. Choosing the Lowest Bid Without Checking References
Price matters, but the cheapest bid can signal shortcuts, inexperience, or subpar materials.
How to Avoid: Review online reviews, ask for references, and compare proposals side by side—not just on price, but on what’s included.
Step-By-Step: Ensuring a Flawless HVAC Installation
1. Research and Shortlist Qualified Contractors
- Look for licensing, insurance, and industry certifications (e.g., NATE, ACCA).
- Ask about experience with your specific type of system (central, ductless, heat pump, etc.).
2. Schedule a Comprehensive Home Evaluation
- Contractor should inspect attic, crawlspaces, insulation, and ductwork.
- Expect questions about comfort issues in different rooms.
3. Request a Manual J Load Calculation
- Verify that the contractor isn’t just using rules of thumb or square footage alone.
- Ask to see the calculation—don’t be shy!
4. Review Equipment and Options
- Compare efficiency ratings (SEER, EER, HSPF, AFUE).
- Discuss smart thermostat integration, air filtration, and ventilation add-ons.
5. Get a Detailed Written Proposal
- Check for model numbers, warranty info, scope of work, and any exclusions.
- Clarify timeline and payment schedule.
6. Schedule and Prepare for Installation
- Clear work areas and provide access as needed.
- Ask for an overview of the installation process and daily schedule.
7. Oversee Key Installation Points
- Verify placement of indoor and outdoor equipment.
- Ensure all connections are tight, insulated, and sealed.
- Check that filter is accessible and labeled with size/type.
8. Commissioning and Final Inspection
- Request a commissioning report.
- Confirm permit inspection is scheduled and passed.
9. Walk-Through and System Orientation
- Have the installer demonstrate system controls, filter changes, and thermostat programming.
- Ask for all manuals and warranty paperwork.
10. Set a Maintenance Reminder
- Log filter change schedule and annual professional checkups.
Frequently Overlooked Details That Impact Performance
Thermostat Placement
Thermostats should be located away from direct sunlight, drafts, kitchens, and electronics to avoid inaccurate readings.
Condensate Drainage
A clogged or improperly routed condensate line can cause water damage and mold. Ensure installers use a trap, slope the line correctly, and install a float switch if possible.
Electrical Upgrades
New high-efficiency systems may require upgraded wiring, breakers, or surge protection. Don’t let this step be skipped to save time or money.
Communication with Other Trades
If your project involves other work (electrical, plumbing, remodeling), make sure the HVAC team coordinates with them to avoid conflicts and ensure everything is up to code.
Red Flags: Signs of a Problematic HVAC Installation
- Excessive noise during operation
- Hot or cold spots in the home
- Short cycling (system turns on/off rapidly)
- High energy bills without improved comfort
- Weak airflow at supply registers
- Visible gaps or poorly sealed ductwork
- Condensation or water leaks near equipment
- Difficulty accessing air filter or controls
If you notice any of these issues after installation, contact your installer promptly—these are not “normal” and can usually be corrected if addressed early.
Proactive Tips for Long-Term HVAC Success
- Change filters on schedule—set calendar reminders
- Schedule annual professional maintenance
- Keep outdoor units clear of debris and vegetation
- Monitor humidity and consider a dehumidifier if needed
- Ask your installer about warranty registration
- Retain all installation and permit records for future reference
Conclusion: Invest in Expertise for Lasting Comfort
HVAC installation is not just another item to check off your move-in or renovation to-do list. It is a major investment with direct impacts on your comfort, health, and home’s value. By understanding and avoiding these common mistakes, you’re taking a proactive role that will pay dividends for years to come. Proper sizing, ductwork design, ventilation, and attention to detail aren’t just technicalities—they are the foundation of a system that quietly keeps you comfortable through every season.
Remember, the lowest bid is rarely the best value. Prioritize contractors who take the time to explain their process, inspect your home thoroughly, and provide transparent proposals. Don’t hesitate to ask questions or request documentation at every step. The right professional will welcome your involvement and ensure you feel confident in your choices.
As a new homeowner, you have the opportunity to set a high standard for your home’s HVAC performance. By following the guidance in this post, you’ll avoid the pitfalls that plague so many installations, ensure your system runs efficiently, and enjoy clean, comfortable air for years to come. Make your HVAC investment count—it’s the heart of a healthy, happy home.
The article mentions that improper sizing is a common mistake, but how can a homeowner independently verify that their HVAC contractor is recommending the right size system before installation starts? Are there specific calculations or documentation we should ask to see?
To ensure your contractor recommends the right HVAC size, ask for a Manual J load calculation. This calculation considers your home’s square footage, insulation, windows, and other factors. Request to see the completed Manual J report, and don’t hesitate to review it or even get a second opinion from another contractor or energy auditor. Avoid accepting recommendations based solely on your home’s size or the old system’s capacity.
When replacing an older HVAC system, are there key differences in compliance requirements or safety codes that new homeowners should be aware of compared to installing a brand-new system in a new build?
Yes, replacing an older HVAC system often involves different compliance steps than installing in a new build. For replacements, local codes may require upgrades to existing ductwork, electrical, or ventilation to meet current standards. Safety codes around refrigerants and efficiency ratings may also have changed since your original system was installed. Always check with your local building department so your replacement meets updated safety and efficiency regulations.
If I’m overseeing my own installation, how can I make sure everything is compliant with local building and safety codes? Are there certain inspections or paperwork I should request before the final sign-off?
To ensure your HVAC installation complies with local codes, start by obtaining the necessary permits from your local building department. During and after installation, schedule required inspections—typically one after rough-in and another at completion. Ask for documentation from your installer, such as permits, inspection reports, and system manuals. Keeping these records will help you have everything in order before final sign-off.
I see ductwork issues can cause uneven airflow. If I already notice some rooms aren’t heating or cooling as well as others, does that mean my ductwork was installed wrong, or could there be an easy fix before calling a contractor?
Uneven heating or cooling in different rooms can definitely be related to ductwork, but it doesn’t always mean the installation was done incorrectly. Sometimes, issues like closed or blocked vents, dirty air filters, or furniture obstructing airflow can cause similar problems. Try checking those first. If the issue persists after these quick checks, then it may be worth having a professional inspect your ductwork for leaks, poor design, or other installation issues.
I’m budgeting for my first HVAC replacement and want to avoid chronic breakdowns caused by poor installation. Are there certain professional certifications or installation guarantees I should insist on when hiring a contractor to make sure it’s done right the first time?
Yes, you should look for contractors who are certified by organizations like NATE (North American Technician Excellence) or have EPA certification for handling refrigerants. These certifications indicate proper training and expertise. Also, ask about installation guarantees or warranties that cover workmanship. Reputable contractors will often back their work with a labor warranty, giving you extra peace of mind against future issues.
Could you elaborate on what you mean by ‘well-sealed, balanced ductwork’? Are there specific warning signs that new homeowners should look for if their ductwork wasn’t installed properly during the initial HVAC installation?
Well-sealed, balanced ductwork means that the seams and joints in your ducts are properly sealed to prevent air leaks, and that airflow is evenly distributed throughout your home. Signs of poorly installed ductwork include rooms that are consistently too hot or cold, weak airflow from vents, whistling noises, or unusually high energy bills. If you notice any of these issues, it’s a good idea to have a professional inspect your ductwork.
You mention the importance of correctly sizing an HVAC system for efficiency and comfort, but how do I know if my contractor is doing the proper calculations? Are there specific questions I should ask or signs that sizing might be off?
To be sure your contractor is correctly sizing your HVAC system, ask if they perform a Manual J load calculation, which considers your home’s size, insulation, windows, and other factors. Request to see their calculation results. Signs of improper sizing include uneven temperatures, short cycling, constant running, or high utility bills. Don’t hesitate to ask for explanations of their process, and avoid contractors who size equipment solely based on square footage or previous systems.
When you discuss code compliance for HVAC installation, how do I find out which local building and safety codes apply to my area, and are there certain permits or inspections I should plan for ahead of time to avoid delays in the process?
To find out which building and safety codes apply, contact your local city or county building department—they can provide the specific HVAC requirements for your area. Typically, a permit is needed before installation begins, and an inspection is required once work is complete. Checking these details early will help you avoid unnecessary delays during your project.
When it comes to ensuring a properly sized HVAC system, are there any specific signs homeowners should look out for if the installer didn’t perform a formal load calculation? I want to avoid efficiency issues but am not sure what questions I should be asking the contractor.
If the installer skipped a formal load calculation, watch for signs like rooms that are too hot or cold, frequent cycling of the system, or high energy bills. Ask your contractor how they determined the size of the unit and whether they considered your home’s square footage, insulation, window types, and orientation. Request a Manual J load calculation for the most accurate sizing.
I noticed local code compliance is highlighted as a factor for successful installation. If I’m planning a major upgrade, what specific permits or inspections should I expect during the HVAC installation process to ensure everything is up to code?
When upgrading your HVAC system, you’ll typically need to obtain a mechanical permit from your local building department before work begins. Expect inspections at different stages—often after the initial installation and before any drywall is closed up, then a final inspection once the job is complete. Specific requirements may vary by area, so it’s wise to check with your local authorities or your HVAC contractor to ensure all permits are pulled and inspections are scheduled properly.
If I discover after installation that certain rooms in my house have uneven temperatures, could this be due to mistakes with the ductwork or sizing, and what steps should I take to have these issues professionally assessed and fixed?
Uneven temperatures in certain rooms can definitely be caused by improper ductwork layout or incorrect system sizing, both of which are common installation mistakes. To address this, contact a licensed HVAC professional to perform a thorough inspection and load calculation. They can assess the ductwork for leaks, blockages, or poor design and verify if your system is appropriately sized for your home’s needs. Based on their findings, they may recommend duct modifications, balancing dampers, or possibly upgrading your system.
You mention system sizing as one of the most important factors for comfort and efficiency. Can you explain how a homeowner can tell if their HVAC system is actually sized correctly for their specific house, especially if they’re not sure how the original calculation was done?
To check if your HVAC system is sized appropriately, look for signs like rooms that are consistently too hot or cold, the system cycling on and off frequently, or unusually high energy bills. You can also request a Manual J load calculation from a licensed HVAC contractor; this assessment takes into account your home’s size, insulation, windows, and climate to determine the proper system size. If you’re unsure about your current setup, a professional evaluation is the best way to know for sure.
The article mentions well-sealed, balanced ductwork as a key factor. If someone suspects their ductwork might be leaky or unbalanced after installation, what are some early warning signs they can look for without specialized tools?
If you think your ductwork might be leaky or unbalanced, watch for rooms that feel hotter or colder than others, weak airflow from some vents, or unusually high energy bills. You might also notice excess dust around your home or hear whistling or rattling sounds from the ducts. These signs can point to issues even if you don’t have special tools.
When it comes to code compliance for an HVAC replacement, what specific permits or inspections should I expect during the process? I want to make sure everything is legally up to standard, but I’m not sure exactly what steps are required.
When replacing an HVAC system, you’ll usually need to obtain a mechanical permit from your local building department before any work begins. Once the system is installed, an inspection is required to ensure everything meets local building codes and manufacturer guidelines. Sometimes, electrical or plumbing permits are also needed if those systems are modified. It’s best to check with your city or county permitting office for the exact requirements in your area.
When it comes to ensuring the ductwork is well-sealed and balanced, is this something a regular home inspection would catch, or do I need to hire a specialized contractor to evaluate it after moving in?
A regular home inspection may only provide a basic visual check of your ductwork and might not catch issues like air leaks or poor balancing. For a thorough assessment, including proper sealing and airflow balance, it’s best to have a specialized HVAC contractor evaluate your system after you move in. They have the tools and expertise needed for detailed testing and adjustments.
You mentioned the importance of ductwork being well-sealed and balanced. For someone with no experience, what’s the best way to verify this after installation, and should I hire a third-party inspector or rely on the installer’s word?
After installation, you can check for obvious duct leaks by feeling for air escaping from joints while the system runs, but a professional inspection is best for peace of mind. Third-party inspectors use specialized tools to test for leaks and proper airflow balance. Hiring an independent inspector ensures unbiased results, whereas relying solely on the installer may not catch all issues.
You mention that improper sizing is a common mistake with new HVAC installations. Can you elaborate on how a homeowner can tell if their system is sized incorrectly after installation? Are there specific signs to look for beyond just uneven heating or cooling?
Absolutely, there are several signs of an incorrectly sized HVAC system besides uneven temperatures. If your system frequently cycles on and off, struggles to reach the thermostat setting, or causes high energy bills, these can all indicate improper sizing. Also, excessive humidity or dryness inside your home may be a clue. If you notice rooms feeling stuffy or hear loud noises from the unit, it’s worth having a professional reassess your system’s size and performance.
You mention that improper system sizing is a common mistake. As someone with no HVAC experience, how do I accurately figure out the right size system for my home? Are there specific calculations or tools I should ask my installer to use?
To get the right HVAC size, your installer should perform a Manual J load calculation. This detailed process takes into account your home’s square footage, insulation, windows, layout, and climate. You don’t have to do the math yourself, but it’s important to ask your installer specifically about Manual J—reputable professionals will use this method, rather than just basing their recommendation on square footage alone.
You talked about making sure ductwork is well-sealed and balanced to avoid uneven airflow. Are there any warning signs I should look for after moving in that might indicate my ducts weren’t installed correctly?
Yes, there are several signs that could indicate your ductwork wasn’t installed properly. Watch out for rooms that are consistently hotter or colder than others, unusually high energy bills, weak airflow from some vents, or excessive dust in your home. Strange noises like rattling or whistling coming from the ducts can also be a red flag. If you notice any of these, it’s a good idea to have a professional inspect your system.
I’m in the planning stage for a full HVAC replacement. Could you provide more information on what code compliance checks I should personally verify, or is this only something a professional handles start to finish?
While licensed professionals are responsible for meeting all local code requirements during HVAC installation, it’s wise to be informed as a homeowner. You can ask your contractor to confirm that permits are secured, equipment meets efficiency codes, and ductwork is properly sealed. Request final inspection documentation from your city or county to ensure official compliance. Staying involved helps ensure the work meets standards.
As someone moving into an older property, I’m a bit confused about compliance requirements. Are there specific codes or certificates I should ask my installer for to ensure everything’s up to the latest standard?
When moving into an older property, it’s important to ensure any HVAC work meets local building codes. Ask your installer for documentation that shows compliance, such as permits pulled for the job and a certificate of occupancy if major changes are made. You can also request a copy of their HVAC contractor’s license and proof that the installation meets current safety and energy standards.
You mention the importance of proper system sizing for efficiency and comfort. What steps can homeowners take to verify that their contractor is using the right method and calculations during the sizing process rather than just replacing the old unit with the same capacity?
To ensure your contractor is correctly sizing your HVAC system, ask if they’re performing a Manual J load calculation. This involves evaluating your home’s square footage, insulation, windows, orientation, and other factors—not just using your old system’s size. Request a copy of the load calculation results and have them explain their recommendations. This approach helps guarantee you get a system that fits your home’s unique needs.
Is there a way for homeowners with little HVAC knowledge to tell if their ductwork is properly sealed and balanced, or is that something only a professional can assess during installation?
Homeowners can do some basic checks to spot obvious ductwork issues, like feeling for air leaks by running your hand along exposed ducts while the system is on, or listening for whistling sounds. Uneven heating or cooling in different rooms may also signal a problem. However, a full assessment of proper sealing and balancing often requires specialized tools and expertise, so it’s best to have a professional handle a thorough inspection.
You mention compliance with local building and safety codes as a key factor. If my property is older and I’m replacing an HVAC system, what should I look out for in terms of code updates or additional inspections?
When replacing an HVAC system in an older property, check if any wiring, ductwork, or venting needs to be updated to meet current codes, as these regulations often change over time. Ask your licensed HVAC contractor to review local requirements and secure the proper permits. In many areas, an official inspection will be needed after installation to confirm compliance, so be sure to schedule this with your local building department.
You mention that professional installation helps guarantee compliance with local building and safety codes. For someone new to homeownership, what questions should I ask a potential HVAC contractor to make sure they actually follow these codes and best practices?
When speaking with potential HVAC contractors, ask if they are licensed and insured, and request proof. Inquire about their experience working with local codes and whether they will obtain necessary permits for your installation. You can also ask how they stay updated on code changes and if they are familiar with energy efficiency standards in your area. Finally, you might request references from past clients or examples of recent code-compliant installations.
If I want to make sure my new HVAC setup meets all building and safety codes, should I request certain documentation or inspections before final payment? I’m worried about missing something that could affect my warranty or future home sale.
It’s a smart idea to request documentation like permits, inspection reports, and a certificate of completion from your HVAC contractor before making the final payment. These documents prove your system was installed to code and can be critical for your warranty and during a future home sale. You can also ask for the manufacturer’s warranty paperwork and maintenance instructions.
Since you talk about avoiding ductwork disasters, can you clarify what signs a homeowner should look for after installation to catch any duct issues early? For example, are there particular rooms or vents that are more prone to problems?
After installation, keep an eye out for rooms that feel stuffy, uneven temperatures throughout the house, or weak airflow from certain vents—these can signal duct issues. Pay special attention to rooms farthest from the HVAC unit and upstairs spaces, as these are often most affected by poor ductwork. Also, listen for rattling or whistling sounds near vents, which may indicate leaks or loose connections.
If someone is replacing an old HVAC system, are there specific steps they should take to make sure the new installation meets updated local building and safety codes, or is this usually handled entirely by the contractor?
When replacing an old HVAC system, contractors are typically responsible for ensuring the new installation meets all current local building and safety codes. However, it’s wise to confirm that your contractor is licensed, pulls any required permits, and schedules inspections if needed. You can also ask for documentation showing code compliance once the work is finished for your peace of mind.
I’m a bit concerned about compliance and safety codes that you highlighted. If my HVAC installer says they have it covered, should I still ask to see specific permits or documentation? What are the most common code issues new homeowners might overlook during installation?
It’s wise to ask to see permits or documentation, even if your installer assures you everything is handled. This gives you peace of mind and ensures compliance. Common code issues new homeowners might miss include incorrect duct sizing, improper venting, inadequate clearances around equipment, and missing carbon monoxide detectors. Confirming paperwork and doing a walkthrough can help you avoid these problems.
Could you explain a bit more about how to tell if my new HVAC system has been sized correctly? The article mentions this as a key factor, but I’m not sure what signs to look for or which questions I should ask my installer.
To check if your HVAC system is sized correctly, watch for signs like frequent cycling on and off, uneven temperatures between rooms, or high energy bills—these can point to sizing issues. Ask your installer if they performed a Manual J load calculation, which considers your home’s size, insulation, and other factors. Also, ask them to explain why they selected the specific unit size for your home based on their calculations.
You say that well-sealed, balanced ductwork is essential to avoid leaks and uneven airflow. Are there simple ways for a homeowner to check if the new ductwork was installed correctly, or should this always be left to a professional inspection?
Homeowners can do a basic check by feeling for air leaks around duct joints while the system is running and making sure all vents have steady airflow. You can also look for disconnected or visibly damaged ducts. However, a professional inspection is recommended for a thorough evaluation, as pros have tools to detect hidden leaks and ensure proper balancing throughout your system.
I noticed you referenced local building and safety codes as part of a quality HVAC installation. Are there common code issues in older homes that I should look out for if I’m replacing an outdated system, especially in terms of safety or compliance?
Absolutely, older homes often have HVAC setups that don’t meet current codes. Look out for outdated wiring, insufficient clearances around equipment, improper venting of combustion gases, or missing safety shutoffs. Ductwork may also be undersized or poorly sealed by today’s standards. Before replacing your system, have a licensed HVAC professional inspect for these issues so your new installation will be safe and code-compliant.