S350-28 balances have failed

A home owner from Alameda says:

I have had 3 of the 4 channel balances from this order fail. First one lasted 2 days after I installed it, 2nd one maybe a week, and third one failed almost immediately after installation--just tonight.

Please see attached pictures.

Basically, the same failure pattern in all 3:
metal hook detached from the cord,
cord is all tattered at the end
in 2 of 3 cases rivets holding the spring also failing

I ordered similar channel balances from you before, I think last year, and those are working fine. This time, however, failure almost right away :-(

Let me know what you think and what you can do for me.

Please let me know if you would like additional/better pictures or anything else.
Thank you.

User submitted photo of their window hardware.
Profile picture of Paul
Paul from SWISCO responded:
Hello, Mikhail. Were the balances that failed the same size and strength as the old balances? Did they happen to look different in any way, such as the shape of the nylon attachments or the location of the pulley wheels? Finally, do you have an old balance take a picture of? We would like to resolve this problem for you but will need more information about the old parts.
A quick learner says:
Hi Paul,

The balances were the same size and strength. Please see attached pictures of original balance. This window now has one of the original balances and one of your balances installed.
User submitted photos of a window balance.
A quick learner says:
Here are pictures of the new (SWISCO) balance on the same window. That's the only 1 of 4 still functioning.
User submitted photos of a window balance.
A quick learner says:
And finally here is the full view of old and new balances.
User submitted photos of a window balance.
A quick learner says:
As I mentioned in original post, I ordered the same kind of balances from you before, in Sept 2014, and they have been working fine, until 30 min ago, when one of them failed in exactly the same way while opening the window. So from that order 3 of 4 are still okay after about 1 year, but 1 is also gone. From the recent order, 1 out of 4 is still working.

I now am suspecting that the reason these are failing could be one of two:

1. The cord is not attached to the hook securely enough. It is just folded under itself and is supposed to be held their by friction, but sooner or later it slips out. However the ends of cord looked really frayed, which I cannot really explain.

2. Second possibility that I can think of is because cord is looped over the side of the metal hook, it could become cut by sharp edges of the balance. That would explain the frayed end.

Please let me know what you think. Thank you.
Profile picture of Paul
Paul from SWISCO responded:
This is very peculiar. Especially now since the older balances are suddenly breaking at the same time. That seems very unlikely since they've been fine this whole time. There must be some external issue that is affecting them. Have your window sashes had their glass replaced at all recently? What is the weight of each sash? All your balances have the 2740 options, which can support sashes weighing 19 through 26 pounds.
Reply to Thread
Use this form to ask a follow-up question or to share your experience regarding this subject.
(your email address will be kept private and is only used to inform you when a response has been made)