So our windows have started whistling, actually more of a hum, and I can't work out where it's coming from.
The windows are UPC fitted two years ago. They're still under warranty so I can get the supplier to come back and fix it but I need to be able to identify the problem because you can bet the wind won't be blowing the day I get them back. I can't work out whether there is a draft coming around the frame or through the frame or whether it's around the glass panel or what. Several windows do it and one was doing it while the light was open so it can't be a seal on the light. Another does it in a corner of the frame where there is no light (edge of a bay window) so I'm thinking it's something to do with the frame but I've tried sealing around the frame inside and out and it's still doing it. I'm running out of ideas. The problem didn't exist initially and seems to have got worse so I'm think that some sealant used by the fitters is drying out and no longer seals. But where?
Has anyone had any similar experiences?