I have a problem with a triple glazed sealed unit. The inner and outer panes are bowed inwards, towards the middle pane. They are badly bowed enough that they actually touch the middle pane at the centre of the window, especially during the winter when it's colder.

 

From what I've worked out so far, this is most likely a manufacturing defect, and is caused by the pressure inside the unit being too low. Although, it could perhaps also be the case that the panes are simply not flat, and the distortion is intrinsic rather than being caused by a pressure difference.

 

Of course, to fix this, I could simply replace that unit. But aside from the expense of a new unit, because of the particular window system, I know it would not be straightforward job and might require a partial dismantling of the frame.

 

My question is, is there any way of trying to fix this in situ? I find some references to the possibility that there is a specialist repair which involves drilling a small hole through the frame and edge spacers, or maybe even through the glass, but I can't find any company that explicitly offers this. If anyone has any info or experience with this, it would be gratefully received.

I’d say it’s a glass supplier issue from what you’re saying. Has it just been installed or installed for a while? It should be covered under warranty. 
 

Firm yourself up with GGF guidelines. https://www.ggf.org.uk we all follow them even if not a member.

 

I’d expect a manufacturer claim with the glass supplier, unless the manufacturer got specs wrong which then means their issue.

Edited March 14, 20224 yr by craig

6 hours ago, craig said:

I’d say it’s a glass supplier issue from what you’re saying. Has it just been installed or installed for a while? It should be covered under warranty. 
 

Firm yourself up with GGF guidelines. https://www.ggf.org.uk we all follow them even if not a member.

 

I’d expect a manufacturer claim with the glass supplier, unless the manufacturer got specs wrong which then means their issue.

 

It's been installed for a little while - is technically under warranty but from a company who have now shut up shop in the UK and don't seem interested in honouring it. So, I doubt I'm going to have any luck there.

 

The question is about what the options are for fixing it, rather than who pays for it.

 

Will have a look at the GGF website, thanks.

Highly unlikely this is bowed panes, large lightweight units really need to be sealed at the lowest expected temperature or not sealed at all. Many double and triple units in very cold areas are not fully sealed for this very reason.

on hot days the fill expands pushing the panes apart which looks weird but is fine, the problem is the panes touching on cold days causing an immediate thermal bridge. A simple hole in the pane or edge seal will prevent the distortion but can allow fogging

On 15/03/2022 at 07:54, markc said:

the problem is the panes touching on cold days causing an immediate thermal bridge.

Yes, this is exactly what happens.