I recently had some builders in working on the kitchen. I have a new glow worm combi boiler in the bathroom that has been working fine since its installation last August. I came home on Friday (I don't know what reason the builders would have to mess with the boiler but they have) to find that the boiler was empty, I filled it up and the heating began to work but no hot water was coming out the hot water tap. I noticed that hot water is occasionally coming out the cold tap. What have they done!!?? Please help
