Your window is trying to tell you: The house is not adequately ventilated, or there is a high moisture level in the home. This is less of a window problem and more of a moisture issue, but your window provides the telltale sign.The moisture forms as condensation or frost on the windows when the temperature dips below freezing. This can lead to mold, mildew, or rotting wood sills. "It's the perfect environment for mold," Minoli says. "Newer houses are built so tight that any moisture inside will stay there unless you do something to reduce it."It's a balancing act to reduce the moisture level indoors without having the house too dry, but when you see condensation forming, you can run a dehumidifier, run bathroom fans, or open a single window for about 15 minutes a day to exchange inside air for dry outside air, Minoli explains.Your window is trying to tell you: The seals on the double- or triple-pane window are deteriorating or have already failed, letting outside air in. Moisture gets trapped between the panes and condenses into droplets or turns foggy.

"The entire window would not have to be replaced," Minoli says. "A moisture-failed panel can be easily replaced with a new one."Your window is trying to tell you: You've probably got a gas leak.This can be a problem in double-pane, gas-filled windows. The gas, typically argon, leaks out from between the two panes or settles to the bottom of the window, causing the glass to bow inward. In some cases, the centers of the two panes actually touch. "This usually causes a rainbow effect and leaves scratch marks on the inside of the unit where the two panes touch," Minoli says. "This often happens during the manufacturing process."Once the gas leaks out, the window no longer provides good insulation, which is why the glass gets cold in the winter. "Argon acts as an insulator," Minoli says, adding that replacing the window is the only way to solve the problem, and the issue may be covered under a warranty. "The window may not be ruined; it's sometimes hard to detect when the gas has dissipated over time, but you're paying for what you've lost in insulation."

Your window is trying to tell you: The wood is swelling.Wood windows swell when they're damp or air humidity is high, making them tough to operate. When the temperature or humidity changes, the window may work smoothly again. If that's the case, you can gently plane or sand down the wood panes to make them slide easily year-round.Wood and vinyl windows have mechanisms such as springs under tension to make it easier to open and close them. Minoli says he's seen the mechanisms fail in as little as five years, making the windows difficult to operate. "It's a common issue," he says. "The parts may need to be replaced, and they usually cost $15 to $20." Minoli says that adding a silicon or other lubricant in the sliding track can make the window open and close more easily.Your window is trying to tell you: Debris is built up in the window track, or the moving parts need to be cleaned and lubricated or replaced. Casement windows require maintenance to operate efficiently. "Mechanisms wear out, like the operator handle, but it's fairly easy to switch them out," Minoli says.

Cleaning moving parts along with the track and applying a lubricant can also help. low pressure side of ac unitIf the weatherstripping is sticky, the sash can be hard to open. ac unit ampsApply a dry lubricant to the weatherstripping; air conditioning unit without ventdon't use an oil lubricant—they attract dirt and dust. Pop off the plastic cover over the crank and apply a lithium grease to the gears to keep them turning smoothly.Your window is trying to tell you: The window isn't closing tightly. First, make sure you're locking the window, which can form a tighter seal. During intense rains, water can end up in the window track. "Rain gets in the track and doesn't drain out," Minoli says, adding that hard winds can blow the water inside once the windows are opened.

If a window is shut tight and water is still getting inside, and especially if the leak is happening near the top, then there's some bad news. The leak is probably not due to the window, Minoli says. Instead, it's probably coming from somewhere else, such as the roof or siding, and the water is dripping down the wall and entering at the window.Your window is trying to tell you: Either the panes or the weatherstripping around the sashes need to be replaced. "The air transfer is through the glass in the window," Minoli explains. "For a large window, the area is big enough for air transfer that it can feel like a draft. This usually has to do with the design of the window." Stopping the draft requires a new window that's more energy efficient. Windows are rated with a U-value. Unlike the R-value of insulation, the lower the U number, the better the insulation of the window.Otherwise, the weatherstripping may be coming loose around the sash. If the stripping is peeling off or has chunks missing, it needs to be replaced.

Stopping the drafts should lower your energy bills and improve your comfort indoors.Step 1: check your water tempShow All ItemsHome & GardenHome ImprovementWindowsHow to Seal Windows How to Seal Windows You seal air leaks and water leaks around your windows in the same way — by caulking and replacing weatherstripping. You can also inject foam sealant between the frame of the window and the frame of the house. A window that leaks air can also mean excessive energy loss and cost. Summer or winter, you don’t want your house to leak air, especially if you spend your hard-earned dollars warming or cooling it. Test a window for leaks by burning an incense stick near all its joints and connections. If the smoke flickers, you have an air leak. Where one section of the window meets another Where the windows meet the frame Where the frame meets the wall Often, water leaks at a window result from a breakdown in the connection between the window frame and the wall.

To prevent leaks, caulk the window where it meets the exterior siding. If the window is surrounded by wood trim, use a high-grade polyurethane caulk to seal all gaps between the trim and the siding (and the trim and the window). Take special care to seal the top side of the top piece of trim. Puddling water at this location causes many window leaks. If you’re willing to remove either your exterior or interior window trim, you can do a much better job of sealing window and door leaks — permanently! — than you can with just caulk. Using expanding foam not only prevents air infiltration, but it also makes the treated area watertight. Here’s how to do it: Use a pry bar and a hammer to remove the window trim (either inside or outside — not both). Fill the void with expanding spray foam in a can. Don’t worry about overfilling. Let it bulge out of the wall. What you don’t want to do is touch the foam while it’s wet; you’ll make a huge, hard-to-clean-up mess.

After the foam dries (it’ll take several hours), use a knife to cut off the excess. Replace the trim in the reverse order in which you removed it and touch up paint as necessary. Leaks also occur when weatherstripping wears out. You may have to remove the operable portion of the window to find the weatherstripping: For sliding windows, open them halfway and lift the window out of the bottom track. Then pull the window out of the opening bottom first. For single-hung windows, usually you just release a lever on the side track(s) of the window frame. Contact the manufacturer for specific instructions. After you remove the operable portion of the window, it becomes pretty obvious where the weatherstripping is and how it has to be replaced. Most home centers offer replacement weatherstripping in peel-and-stick rolls. If you aren’t sure about what to do, take the section that you removed to the store with you or photograph the area that needs attention. You may need an adhesive solvent to unstick old weatherstripping.