How Can I Clean My Yellowed uPVC Door?
You need to be aware that if your uPVC door has turned yellow this does not mean that it is dirty. Therefore, if it is not dirty then you cannot clean it and must not attempt to clean it. We have seen some terrible cases were people have used ever increasingly harsh chemicals in an attempt to bring things up nice and white – the only thing people have succeeded in doing under these circumstances is damaging the upvc.
The reason your uPVC has turned yellow is that you have a low quality uPVC material. We don’t want to make assumptions but some window companies buy in very poor quality upvc which does not have enough Titanium Dioxide in it (this is the pigment that makes upvc so nice and crisp white).
High quality upvc windows and doors should retain their new, white look for the entirety of their guarantee. Poor quality uPVC tends to turn yellow after only a couple of years due to the action of sunlight reacting with the chemicals deep in the plastic.
The only way to fix this is to replace the door with a new, high quality one. Do not attempt to paint it – you will only further damage the door.