When changing a washer on the kitchen tap we turned off the mains water supply from under the sink. However, when turning it back on we no longer have hot water in any taps and also no cold water in the shower or bath. Cold water in all sinks works fine.
Our system is gravity fed and it seems the tank in the loft is filling very slowely (only a drip).
Does anyone have any advice on what could be causing it and how to solve this?