Using economical heaters uneconomically

Grrr! I'm tight-fisted. I hate wasting money. I'm not great in the mornings. Especially when it's wet and horrible out. I switch the heating off if we don't need it on...

So imagine my delight when I opened the living room door this morning to be met by a wall of heat because someone didn't switch the heater off last night...

Grrr!