How to Replace Andersen's Narroline Sash Balances

Like many Andersen products, their balances are exclusive to their windows. We hope to shed some light on the process we use to identify the correct replacement but, when in doubt, our experts at SWISCO will always help you see the job through.

Andersen narroline sash balance

If you have Andersen double-hung Narroline windows that were manufactured between 1968 and 2012 that will not open or stay open, then the sash balances may be broken and need to be replaced. Unlike most other window manufacturers, Andersen typically uses a unique type of counterbalance commonly referred to as an Andersen sash balance. Replacing this hardware is a cost-effective solution for repairing yours or your client’s windows. This guide details how to determine the correct replacement Andersen sash balance for your application.


The most reliable way to identify the correct replacement balances for an Andersen window is to remove the original hardware in order to take note of all the stamp codes on the metal balance box. As the video below illustrates, there are a number of steps to replacing these balances. If you are uncertain you can complete this procedure on your own, hiring a handy person to assist you may be helpful.

Be very careful not to damage the jamb liner when removing it and make sure to take extra caution if they are already brittle. One tip to make the process easier is to add soapy water to the window sill. This acts as lubrication and can ease the process of getting the jamb liner out. In the event that the jamb liner is damaged, SWISCO cannot replace this, and you would have to contact an Andersen window dealer directly for assistance.


Once you have removed your Andersen balance from the window, you are then ready to identify the proper replacement. Take note of any and all the stamp codes along the surface of the metal box. One specific group of numbers, usually three or four digits, will typically designate the replacement you need. This exact code could be anywhere on the metal box, so it’s best to take note of all stamp codes to be safe.

The way in which the numbers are stamped on the box is often just as important as the numbers themselves. We highly recommend that you photograph all the stamps on the front and back of your old Andersen balance and contact our experts on the SWISCO’s discussion board, as we should be able to quickly identify the new balance you need.

Example of the 24-939 stamp
Example of the 24-939 stamp

In our example, the stamp code includes the numbers 939. As it turns out, this is the key group of numbers needed to identify your replacement. Andersen balances with stamps including 927, 931, 937 and 939 can be replaced by our 24-939. Other sash balances in our inventory will support different groups of stamps based on the amount of tension needed to support your window sash.

One final note: in some instances, you will find older Andersen balances that lack the ‘side tab’s that newer versions as well as our replacements feature. This creates an issue because then there’s no room in your window frame for the tab to fit. To get around this, you can chisel out space to fit the tabs on our replacement balances. See the diagram below.

Older andersen window installation diagram

Like many Andersen products, Andersen sash balances are exclusive to their windows. Since they’re quite different from other window balance hardware, unique steps have to be taken when replacing them. When in doubt, our experts at SWISCO will help you see the job through.

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