As a rookie (4 nights on a campsite and counting) and as someone who considers anything electrical as the Dark Arts, could someone please explain my Burstner manual in reference to the Truma Heater/Boiler. Regarding the operating mode; i.e. electric, gas or mix; our Burstner manual says "Select the output level for 230v electrical operation so that it corresponds to the fuse protection of the 230v connection (900 W for a 3.9 A fuse, 1800 W for a 7.8 A fuse)". If I am on EHU on a UK campsite, how can I tell what the fuse protection is? Likewise, when plugged into a standard UK socket (say when EHU at home)?; and how about overseas? How do I know whether to select the Electrical 900W or Electrical 1800 W option on the Truma display unit?