You can fit a timer similar to this:

http://cgi.ebay.co.uk/Wired-Immersion-Heater-7-Day-Electric-Timer-T106-C_W0QQitemZ190259847948QQcmdZViewItem?hash=item190 259847948&_trkparms=72%3A1301|39%3A1|66%3A2|65%3A1 2|240%3A1318&_trksid=p3286.c0.m14


From cold it will take around an hour to heat up.

If it's an older cylinder with a loose jacket, buy a new one and wrap the tank up tight. It will pay for itself in a few weeks.

If it's a modern one with sprayed on foam lagging it will keep heat quite well.

If it's around 5 years old or newer it should have a manual reset over temperature device as part of the thermostat, if your heater suddenly stops working check to see if that resets first.

Thermostat shouldn't be set any higher than 60, 55 is safer but the water will run cold sooner at that temperature.

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