Hello, This might be a daft question. I had a leak in the cold water pipe. The water has been mostly off for a week. The leak is fixed and when the water was turned back on the plumber (arranged by my home emergency cover) could hear the header tank filling in the loft, said all was good and left. I went and turned the control back to heat the water but the hot water cylinder sounds empty and if I run the hot tap I get cold water and hear the loft tank filling. Any ideas what is going on? Thanks