Everything You Need to Know: Window Balances

A Definitive Guide to Window Balances

April 3rd, 2019
5 minute read

Window balances are pieces of hardware used to regulate the opening and closing of the window sash. All hung windows use them in some capacity but few homeowners consider how their windows operate until a window takes too much effort to close, or slams closed suddenly. These are both good indicators that the window balances are due to be replaced. Most homeowners assume that they are going to have to replace their windows, which is not true in most cases.

Trying to fix a broken window balance system can be frustrating for someone with no experience in the window industry. The goal for this guide is to walk through the types of balances systems and what is needed to replace them. 

We always suggest replacing both assemblies at the same time. Repairing one side can cause the older balance to break under the additional stress of keeping up with the new balance or the new balance to break prematurely while trying to support most of the windows weight. 

The first step is to remove an undamaged balance from the window to compare to the available replacement options. This process depends on the type of balance you have. Below are the common balance styles found in residential windows.

* Rod balances are an outdated style of balance that can be replaced with a better quality channel balance. See our full conversion video that will walk you through the process step-by-step. 


Channel Balances


Also known as block-and-tackle balances, channel balances contain a spring and pulley system within a metal channel. They usually feature a unique combination of fittings or attachments at either or both ends. The spring mechanism is carefully calibrated to support the weight of a window. You can remove channel balances from a non-tilt window by watching the video below or by following the written instructions in SWISCO’s channel balance removal guide.

Once you’ve removed the balance, locate the strength code on the metal channel. Unfortunately, this code doesn’t identify your balance — just the spring strength needed to support the weight of your window.

For example, if your stamp is “28 3” or “28 C”, you’d choose the strength option “2830” to support a window weighing between 16 lbs. and 23 lbs for some standard balance series.

If there is no visible stamp, check another balance from an identical window. If you still can’t locate a stamp on any of your balance channels, you can remove the window sash and place it on a bathroom scale, or step on the scale while holding the sash and subtract your weight.

Using the weight of your sash, review the weight ranges associated with each “stamp option” once you’ve identified the correct balance series.

You’ll have to confirm a few dimensions to narrow down your replacement options. Measure the length of the metal channel, not including the end fittings, as well as the width of the channel.


Now that you know the stamp and the channel size, you’ll need to compare the style and depth of your balance fittings to the options in our catalog.

These pieces help to keep the balance snug in the track and against the sash. Getting something even 1/32” off can make a difference.

You can find a more comprehensive overview of these fittings and their differences in the Classifying Channel Balance Fittings guide.

For a tilt window channel balance, you’ll need to determine if the balance channel has a ribbed or straight, plain style channel. 


Next, you’ll compare your balance fitting to the options in the plain or ribbed channel sections in the SWISCO catalog.

Remember to check the integrity of the parts that work with your channel balances such as the take-out clips and top sash guides for non-tilt windows; as well as the pivot bars, pivot shoes and tilt latches for tilt-windows.

As always, make sure to contact the experts with a photo of any part that you’re unable to locate a replacement for.

Coil Balance


A coil balance, sometimes referred to as a spring or constant force balance, is a type of sash support that uses coil springs anchored to a pivot shoe to enable the window to stay open. Remove your coil balances by following the videos below or follow the written instructions in our guide.

When removing your coil balance, take note of any stamp numbers. Often times, they are found imprinted on the tongue of the metal spring, cartridge or coil casing. If you don’t see one, weigh the window and divide the weight by the number of coils in your window.

Since most coils tend to look very similar, your search for the correct coil will rely heavily on the pivot shoe or coil cartridge. Each series of coil is designed to work with a specific pivot shoe, so if you can identify yours, the compatible coil series will follow. Compare the style and dimensions of yours to our selection.

Other times, the assembly is part of a complete housing unit that comes with a housing, coils and cover.

When replacing your coils, check over the surrounding hardware like the bushing, coil housing, pivot shoes, and pivot bars to make sure you have all the necessary parts to repair the window.

Spiral Balance


Spiral balances are spring mechanisms that are distinguished from other balances by their use of a hand-wound spiral rod that extends from a housing tube. This rod applies tension to the spring, which allows it to keep the sash up when raised. If you have a window that tilts in for cleaning, you can follow our video to remove the spiral balance from the window. 

Next, you’ll need to measure the  length and diameter of the tube that houses the spiral. The 3/8″ diameter Series 900 Spiral Balance and 9/16” (considered ⅝” in the trade) Series 600 Spiral Balance are common replacements for balances that have two pins at the base of the spiral to anchor the assembly to the pivot shoe

You’ll also need to choose the tip color on the balance product page that matches your original hardware. If the tip is missing or faded, you’ll need to weigh the sash and choose the appropriate weight range.

Make sure to check the intengrtity of the pivot shoe that the spiral anchors to. If the shoes need to be replaced as well, compare the style, width, and thickness our replacement options.

Replacing spiral balances for non-tilt windows can be a much trickier process compared to newer tilt windows. They are a dying breed but still turn up in older homes. To remove yours, follow our detailed guide to compare your balance length, diameter and spiral tip to our seleciton of replacement options. Keep in mind that these balances anchor to a bracket screwed to the bottom or side of the sash. 

Items You May Need:
A tilt or non-tilt charging tool. 

If you don’t see what you’re looking for, reach out to us SWISCO’s team of experts for assistance

Andersen Sash Balance


Some, but not all, Andersen windows use a type of box-style overhead balance. These are easy to identify once they’re uninstalled but it does take a fair amount of effort to remove them from the window header.

Once the balance is removed, all that’s left to do is locate the stamp numbers. Usually, there will be multiple stamps on the assemblt but the one that identifies the balance will include either a # symbol, H or P. It can be found in one of the locations indicated in the example below. 

Once you have your number, you can match it up to the corresponding SWISCO product code or reach out the the experts for help.



  • Anonymous

    2 years ago

    Oh, cool! Thanks for taking a second to share my post. We love hearing from readers like you!!

  • Anonymous

    2 years ago

    I like how you mentioned that maybe your window takes too much effort to close. With my wife recently disabled, closing our windows (a difficult task for me) has become impossible for her. We’re thinking of having a window repair expert come take a look and see if we can’t make things a little easier.

    • Anonymous

      2 years ago

      Thanks for commenting! Difficult to open windows are usually a pretty good sign that the balances may be starting to go. Hopefully a repairman can take a look and confirm this is the case for you, too!

  • Anonymous

    1 year ago

    I need parts

  • Anonymous

    1 year ago

    I need to get some Series 775 balances, but my old hardware doesn’t have metal channels, is there anyway to measure to figure out what length channel I need? Thank you

    • Anonymous

      1 year ago

      Thanks for commenting! Your best bet would be to check an identical window in the house, if possible. If not, I would recommend sending over your window dimensions to our experts here – https://www.swisco.com/page-id-part

  • Anonymous

    9 months ago

    Ima contractor and need to replace a set of dual (piggy back) Omega constant force coil balances on a DH window that measures approx. 38 x 52, and I can’t read any of the markings on the existing springs. And there is nothing stamped on them. Is there a chart somewhere that tells what size of springs I need??

  • Anonymous

    9 months ago

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