I Don't Know

I really don't. Electrics are not my area of expertise. Penny and Steve are coming back to the UK at the end of July. Hopefully for ever but at lease for the time being. The tenants have left their flat, so yesterday i popped down there to check on what the managing agents had said in their end of lease report etc. I discovered that the hot water tank was very hot and the hot towel rail was so hot I could only just touch it. Not idea for an empty flat in July. I turned off every switch i could find but none seemed to be related to the hot towel rail. So, I returned to day to review and discovered a cold hot towel rail (= good) but still a hot, hot water tank. 

So my solution was to switch off at the mains both the peak and off peak fuses (the big red switch on the left. I dont think any damage done, just they will have to switch them both on to get any electricity at all. however as there is no one in residence and electricity is the price of liquid gold, i think that this was a reasonable decision.