Top HVAC Installation Mistakes to Avoid

hvac technician is checking air conditioner during hvac installation

A brand new HVAC system will make your life better. It can make you more comfortable, lower the costs of your energy compared to the system you had before, keep you healthy, and increase your productivity. However, dealing with an improper HVAC installation is a complete nightmare. In this case, you will be faced with poor indoor quality, regular HVAC repairs, increased energy costs, premature HVAC system replacement, and discomfort.

If you want the best outcomes, be sure to choose HVAC contractors that are certified and experienced. Homeowners can also play a role by educating themselves about the most common HVAC installation mistakes that HVAC contractors make. This way, they can learn how to avoid them.

Explore Our HVAC Services Call To Schedule A Free, In-Home Estimate

The Most Common HVAC Installation Mistakes to Avoid

This article will cover the most common mistakes that occur when with HVAC system installations.

1. Choosing the Wrong Sized Heating & Cooling System

Many people think that a bigger HVAC system will offer better performance. They have the idea that if they purchase the largest system they can afford, it will be a great investment. This just isn’t the truth. The correct sized system is dependent on what your projected load is. The top contractors will carry out complicated calculations that involve temperatures in the region, shade coming from structures nearby, which way the house is orientated, how high the ceiling is, the total floor area of the interior, and much more. You will be able to determine the precise amount of power your HVAC needs to cool down or heat up your house. Inexperienced HVAC contractors will make erroneous suggestions based on rules of thumb that are inaccurate.


2. Leaving the Old HVAC Ductwork in Place

You might cut costs by installing a new HVAC system but keep your old ductwork. However, this is not always the best way to go. The old ducts could end up being incompatible, especially if you need to change the size of your AC unit or furnace. The previous ductwork might be too small to allow air to flow efficiently. If the ducts were installed a few decades ago, they most likely have mold, leaks, dirt, or additional issues. The previous design may not be ideal for distributing air-conditioned or heated air around your home. Instead, think about getting new ductwork installed by a trusted HVAC contractor.

3. Poor Techniques for HVAC Duct Installation

image of hvac air ducts

HVAC design is different from execution. Some contractors can create designs that make sense and are economical, so in theory, they should work. However, HVAC technicians who are not experienced or just want to finish a job as quickly as possible might use bad installation techniques. For example, they might seal up gaps with tape despite the fact that this should only be a short-term solution. Over time, ductwork leaks will begin and the system will become inefficient. As a result, you will pay more for monthly energy costs. Be sure to hire an HVAC company that is reputable and uses top-notch sealant and materials, like Miller Oil Company.

Call Today: (860) 745-0326

4. Using HVAC Drainage Systems That are Poorly Designed

AC units create water around the coils due to condensation. Whoever installs the air conditioner must ensure that all of the moisture is gathered up and filtered away from the AC system. If it isn’t, the water can leak to other areas in the home. This can result in mildew and mold, the damage of flooring and drywall, and bacterial growth. The area that is affected may become so odorous that you will not be able to ignore it. You can avoid all of these headaches by hiring an HVAC company to do it right the first time. HVAC professionals who are experienced will know how to respond.

5. Venting Toxic Gases Incorrectly

Carbon monoxide alarm on the ceiling

HVAC systems generate toxic gases during combustion, so you need to ensure that the installation includes appropriate venting. When burning fuel, your furnace can create hazardous gases like carbon monoxide. This will not become an issue provided the exhaust system is funneling the gases outside of the home immediately. But if the installation is faulty, these harmful gases can be released inside the house. Every home should have a carbon monoxide detector so that you can be warned of any dangers. Without one, you may not notice the gas, which is odorless and colorless. Ask your contractor about the safety of combustion so you can learn whether they know how to properly facilitate this.

Learn More About Our HVAC Installation Services Call To Schedule A Free, In-Home Estimate

6. Incorrect Placement of the Cooling & Heating System

If the contractor is paying attention, some mistakes are easy to prevent. For example, they should verify the proper location of the HVAC before just putting in new systems where the old HVAC previously was. This may be making a mistake all over again instead of fixing it. For instance, you want to make sure the AC condenser is shielded from sunlight as much as it can be. The system won’t have to work as hard if it is dealing with less direct sunlight. The same is true for the thermostat. If it is located close to any windows, it will get more heated than the remainder of the house and struggle with erroneous sensor readings. An HVAC technician who is experienced will know the best placement for your HVAC system and its parts.

7. Not Clearing Around the Condenser

image of outdoor ac units that do not have enough clearance around them

In order for the condenser to work its best, it needs space around it. Sadly, this doesn’t always happen when HVAC installations are rushed. It might be that the contractor only allowed for clearance of just a few inches around the sides. Experts suggest giving at least two feet of clearance around the sides so that the system can run as efficiently as possible and produce good air intake. Try not to make this mistake if you want to avoid the system consuming more energy than is necessary or suffering from premature degradation. Once the installation is done, the homeowner should keep the area around the system clear by removing objects around it and cutting any plants that are close by.



Mistakes in the installation of HVAC systems are more common than house owners might think. Contractors with experience are regularly called upon to fix the mistakes of less experienced contractors who incorrectly installed the system. You can prevent paying double for services by making correct decisions from the beginning. Now that you are aware of what to keep your eyes on, seek out a contractor in your area who is certified and has an exceptional reputation.

Call To Make An Appointment: (860) 745-0326 Explore Our Case Studies

For Any of Your HVAC Needs, Call Miller Oil Company

Miller Oil Company LogoMiller Oil Company provides the best cooling and heating services in Hartford County, Connecticut. We employ top HVAC technicians who are certified and offer superior HVAC installations, repairs, tune-ups, and replacements. Every one of our knowledgeable technicians has the experience to correctly service your HVAC.

By working with Miller Oil Company, you will receive the best service costs for cooling and heating in the region. With our repair and maintenance services, you will find that your comfort and energy efficiency are improved and your home cooling and heating costs are reduced. If you require a replacement HVAC unit, we can suggest the most appropriate model for your house that is within your budget. We include a satisfaction guarantee for all of our work. Give Miller Oil Company a call now to get your free, in-home estimate or to schedule an appointment.

Call Now: (860) 745-0326 Read Our Reviews

Click here to contact us today or give us a call at (860) 745-0326 if you have any questions.