On Saturday, 27 January 2018 17:21:43 UTC, George Miles wrote:
Is it OK to put my 500 watt frost heater on a lighting circuit?

What's the other loading on the circuit?

A 500 watt space heater is just going to try and heat the whole loft; you'd probably be better to wrap trace heating tape round the tank and pipes and then insulate over that.

Owain