Thanks, a foreigner here so I just parrot what the locals say :). I do have an oil furnace/boiler, which heats the water in the tank. My "immersion heater" the

Thanks, a foreigner here so I just parrot what the locals say :). I do have an oil furnace/boiler, which heats the water in the tank. My "immersion heater" then is so far never been switched on because I just run the boiler for 10 minutes a day.