The bath has one of those secret taps that are not very obvious if you've never used one. So, I decided the only way to fill the bath was with the shower attachment. This does work, but the pressure made the head turn and it started to spray water all over the bathroom. I was clothed at the time so had to undress to get to the shower to turn it off. All but one towel was soaked as to was my shirt.

Then spent a short while investigating the plumbing and worked out there was a device that operated like a tap.