Newbie Question - Water Heater on or off?

Hi guys,

First post from me as a newbie to the club along with being a newbie to caravanning in general too!

Firstly, i've already learnt a lot from everyone's posts and I feel that joining the CC has already been greatly justified, very chuffed with that.

Secondly, it's been eye opening to see how many discussions there are on weights etc and I realise that there are so many people who are towing out on the road illegally, either through blissful ignorance or choice. We had an absolute nightmare couple of weeks where we had to learn very quickly about the minefield of towing laws and essentially were told that our car was not suitable for the van that we wanted (Alfa 147) so we researched online and found that a diesel Focus 1.8 had a towing capacity that suited. Found a suitable Focus and bought it (after checking the V5 twice to confirm that the braked capacity was enough) only to find out later that the plated weights told a different story and that wasn't suitable either.....we'd just paid £5k in cash that afternoon and then I found this out. Fortunately, the dealer had a nice CRV in good nick so we swapped for that :)

AAAAaaanyway......my question! :) We are venturing out this weekend for our 1st trip in the caravan and I wanted to know whether you guys recommend leaving the water heater on at all times or do you just switch it on prior to needing it? I hate wasted energy so would prefer to turn it off before bedtime and on again in the morning but if it takes forever to heat up (we intend on showering in the van) then that might not be practical.

Advice please oh wise ones