Sorry to hijack the thread but i couldnt recomend and immersion heater more, and for a franction of the price of one of these heaters gav, keeps van warm, reels and pump frost free and the water is warm coming thru pole, i cleaned my van at 4 o clock today and it was still warm to touch. Can get an immersion for less than £30, and cost of running about £1.50 a night.