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Window balancing systems, or balancers, are devices that apply force to a window's sash. 

They are found along the sides of single or double hung windows that operate vertically. The weight of the sash needs to be counterbalanced by some type of balancer, otherwise the sash will fall or fail to stay open. 

This page will tell you how to identify a potentially malfunctioning balancing system and provide an overview of the types of balancing systems. See how our Window Wellness Service © can protect and rejuvinate your balancers:

Signs of a malfunctioning balancer

  • Sash is hard to open

  • Sash won't stay open

  • Sash raises by itself

  • Loud noise when opening

  • Visible rust when tilting in

What causes a malfunctioning balancer?

Typically, balancers go bad because of a lack of maintenance. Balancers and their related parts need to be lubricated periodically (every 6 - 12 months depending on environment) and the channels need to be cleaned of any debris. A Window Wellness Service © can lengthen the life of any functional balancer. 


Neglected balancers will rust and slowly require more force to operate. More force puts more stress on the balancer and the vicious cycle degrades the part. When they break (or the shoe breaks), there is no counterbalance to hold your window up.

Acceptable Spiral Balancer

Spiral Balancer Tilt In Edited.jpg

Rusted Spiral Balancer

Rusted Spiral Balancer Edited.jpg

Some balancers fail because they were installed improperly. For example, spiral balancers allow for tension to be fine adjusted with a specialized crank. If they were too tight, the window will raise by itself; too loose and the window will not stay up. Some contractors will even attempt to rig malfunctioning parts in any number of strange ways to make them work temporarily; like this balancer that was wired into a worn shoe.

Other times, the wrong tension of balancer is used for the sash's weight. For example, those same spiral balancers have color coded nylon bearings where the spring extends out that tell how much weight they can support. A heavier window would use black tips and a lighter window would use red tips.

Balancer wired to shoe

Balancer Wired-In To Shoe.jpg

Failed wire released balancer

Wire Holding Assembly Together Snapped.j

Types of Balancers

Spiral Balancers​/Turbo Lifts

Spiral balancers are often found in tilting vinyl windows and consist of a spirally wound helical spring. The top attaches to the window frame with a screw. The bottom has a spiral rod that twists out of the nylon bearing. The end of that spiral has a set of nubs that set into the upper shoe. The shoe connects the balancer to the sash via the pivot pin attached to the sash.

Related, are Turbo Lift balancers, which have a supporting spring surrounding the helical spring. They are used for extra support in heavier windows that are only designed to have one set of balancers, compared to some large loft windows that may have 2 or 3 sets of balancers to hold the sash.

Spiral Balancer

Spiral Balancer Tilt In Edited.jpg

Turbo Lift Balancer

Turbolift Spring Close Up.jpg

Channel Balancers

Channel balancers are often found in non-tilting aluminum windows. They use a spring to counterbalance the sash; The tension in non-adjustable. A hook attaches to an opening in the top to the mainframe and tension is added by installing it. The upper part of the balancer is held in place with a take out clip until the sash is installed. A balancer stop is screwed to the top of the sash and holds the balancer in place after the sash's weight is applied. The channel balancers now move with the sash and the string and spring hold the tension. The clip is then disengaged and presses into the mainframe. Because channel balancers do not tilt in, the sash has to be removed from the window to access the balancers.

Left: top of balancer
Right: bottom of balancer

Take out clip

Channel Balancer Set Upper and Lower.jpg
Channel Balance Take Out Clip.jpg

Constant Force Balancers

Constant force balancers (or Coil-Spring balancers) are a newer balancer found in a wide variety of windows. They use a coil of preformed steel to add tension to counterbalance the sash. They are small and lightweight with less friction than conventional balancing systems. Tension is added by the manufacturer and they are non-adjustable.

Constant Force Balancer in Shoe

Constant Force Balancer.jpg

Knife-latch Balancers

Knife-latch balancers are a variation of channel balancers that use a spring to counterbalance the window. The knife latch locks the balancer in place when the sash is removed by digging into the side channels of the window when the sash is removed. Like channel balancers, they are non adjustable.

Jamb-liner balancers

Jamb-liner balancers use a spring that hooks directly to the shoe to counterbalance the sash. They are included in window kits that install into the jamb of the window, usually in after-market window installations, post-construction. The springs are non-adjustable.

Rope and pulley balancers

Rope and pulley balancers are one of the original models of window balancer. They are found on many old construction windows as they fell out of popularity around the 1950's. The sash is attached to a shoe, which connects to a rope or chain leading up to a pulley contained at the top of the jamb. The sash is held up with actual counterweights hidden in trap doors on either side of the jamb. Because of the nature of these balancers, the tension is only able to be adjusted by ordering heavier or lighter counterweights.

We are able to repair and re-rope balancers on vintage windows like these and can even track down and order counterweights that have been lost or degraded. 



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