On other news, we decided to dust off the inflatable hot tub now the weather has warmed up. The motor has been inside over winter to dry.
Anyway, it took 40 KWh to heat the water - nearly £13

. Once at temperature the heating element stays off for 2 hours, then comes on for about 30 minutes, so about £4 a day to keep at temperature - yikes - the delight of a smart plug ! We've not done this (i.e. left running) since the shooting electric prices, so we usually turn off the heating, letting the tub cool until we decide to use it, which means the cost of a single use is about £5 once a week.
No wonder they are being sold off in DIY/supermarkets, they are ruinously expensive to run.
Anyway, slept like a log last night after 30 minutes of being stewed at 39c !