How leaky windows affet your homes heating

December 27, 2023

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You might notice that your heat has been on more than normal, but your home seems cooler than it should be. This could be because your home is drafty, but you don’t know the source of the drafts. Many people suspect the insulation, walls, floors, and other areas of their home are the source of the problem. However, it might surprise you to know that the cause of your drafts could be your windows. Let’s look at the signs that indicate you have leaky windows and what you can do about it.


Your home could be losing as much as 30% of your home’s heat. It’s not uncommon for older homes to have leaks around the windows due to the windows’ age. Furthermore, even newly built homes may have windows that leak if they are not made of good quality materials. Special energy auditors can use thermography to see parts of the home that leak heat outdoors when it’s cooler outside. If you are having problems heating your home, you should contact a professional to conduct an assessment.


There are many telltale signs that you have leaky windows. For starters, you might be able to feel a draft when you stand in front of your windows. Put your hand out in front of your window and then feel around it to reveal where the source of the leak is coming from. It may only be in one area of the window, or it could be the entire seal around the window. You should also check all the windows in your home for leaks, especially if they are several years old.

Leaks around windows allow moisture and dirt to enter the home and even settle between double-paned windows. If you see cloudy windows, it can be from an excessive amount of moisture that becomes trapped between the windowpanes. You might also see sand or other debris on your inside windowsills that come in from gaps around the window and its frame. If you notice that the curtains covering your windows move when the HVAC system isn’t on, it might be an indication that your window has leaks.

Water can also leak in from your windows and cause a drip when it’s raining outside. This is more of an obvious sign that you have a leaky window. You might see rotted wood around the exterior of your windows. Either way, you are likely to have water damage around your windows.

Condensation is another sign that you have leaky windows. With excessive moisture, you might notice mold or mildew forming around the frames of your windows. You might also notice that the caulk around your windows isn’t so smooth but cracked or falling out. This leaves an area where your windows can leak. When you have these signs, it’s common for windows to have problems opening and closing. These are all signs that your window has leaks and needs immediate attention.

Other signs that could indicate you have leaky windows due to water exposure include flaky, peeling paint beneath your windows, a wall that’s warped and bowed, stained walls, and sagging drywall. If anything looks off around your windows, you should get them inspected by a professional. A small problem can lead to a worse one that could be expensive to fix.


Because leaky windows can leak out warm air during cooler months, it can also allow warm air in during the warmer months. This not only affects your indoor air temperatures, but it causes an issue for your heating costs when it’s cold outside and cooling costs when it’s warm outside.

Beyond heating and cooling costs, your HVAC system will have to work harder to heat your home. When your system must work harder, it will wear out quicker. This can mean extra repairs for your HVAC system or total system replacement. Either apply weather stripping around your windows as a temporary fix or update your home with energy-efficient windows to help put an end to leaks. If leaky windows have caused your HVAC system to work overtime, it might be time to get your HVAC system serviced as well. Regardless, you should get it serviced twice per year to make sure it’s running at optimal levels.


Leaky windows can mean that your home is experiencing fluctuating temperatures in different areas. Your home could be cold at one end and extremely warm at the other end. You should get a professional to help you fix the problem. Without having a comfortable and consistent temperature throughout the home, you could face sleepless nights and feel uncomfortable in general. Newborns, small children, and the elderly are particularly sensitive to uncomfortable temperatures.


You might underestimate the effects of leaking windows on your home until you are unable to maintain a set temperature. A large amount of heat can leak out around windows during cold weather, and this becomes more noticeable when it is extremely cold outside. Conversely, if it is extremely hot outside, you will experience more hot air coming in around the windows. It will be hard to keep your home consistently heated or cooled. Even if you install a new thermostat for temperature control, your HVAC system will become overworked trying to maintain your desired comfort level.

If your home’s heating comfort level cannot be maintained because you have windows that leak, you should consider caulking your windows or having them replaced. Doing this upgrade could extend the lifespan of the heating system. If you are uncomfortable performing repairs or upgrades yourself, you should contact a professional.

Since 2004, Alberta Mountain Air Heating and Air Conditioning in Calgary has been serving residents with heating and cooling services. As a Lennox Premier Dealer, we have a team of technicians who are educated, SAIT certified, and highly skilled to work on all HVAC makes and models. You can trust that our technicians are dedicated to serving you and offering exceptional service. Furthermore, we have earned the Workplace Safety Certificate of Recognition, and our BBB-accredited company maintains an A+ rating by excelling at customer service.


When you have leaky windows, you can have a few other issues, such as an HVAC system that needs maintenance or repairs, a home that needs dehumidification, the need for increased ventilation, and more. At Alberta Mountain Air Heating and Air Conditioning, we can remove humidity from your home, increase ventilation, or service your HVAC system. We also assist homes that operate using gas furnaces, heat pumps, electric furnaces, tankless water heaters, thermostats, and VRF/ERV systems. Whether you live in an older home or in a newly constructed home, we can help you with your home’s heating and cooling needs. Contact Alberta Mountain Air Heating and Air Conditioning today for more information or to schedule service.

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