Low risk
A cloudy haze or trapped water sits between the two panes, and cleaning the glass makes no difference.
Water runs down the room side of the glass most mornings, and wipes away with a cloth.
You can feel cold air moving at the window even with everything shut and locked.
Caution
The window shuts but the handle will not turn to throw the lock, or it turns and nothing engages.
The sash catches on the frame, stands off at one corner, or needs shoving to shut.
The handle needs real force to turn, feels gritty, or has snapped off in your hand.
Timber at the bottom of the frame or sash is soft, dark and gives way under a screwdriver.
Your solicitor or buyer has asked for the paperwork proving your replacement windows were signed off, and you have not got it.
Your replacement windows arrived without the small vents the old ones had, and now the rooms feel stuffy and the glass runs wet.
The window looks fine but there are gaps, cracked filler or bare foam between the frame and the wall.
Describe the job and get a fixed price from a local window fitter.
