The use of hot air repair on PVC-U frames is relatively new, but appears to be growing fairly rapidly. It requires a high level of training and skill to produce satisfactory repairs. If repairs are carried out well, it seems unlikely that repair will have any long-term adverse consequences for the durability of the repaired window or door. This Good Repair Guide describes current practice, some potential problems associated with a new technique and how repair work might develop in the future. 4 pages.