do YOU know the difference?

Do you know the difference between a WATER HEATER and a residential PROPANE TANK? This is how I spend Mondays... on weird stuff like this. It would almost sound like a bad joke overheard in a bar "This guy comes into the office and wants to order propane..." Why is this funny? After looking up the address in BOTH databases and not finding a tank there, he insists. So a driver gets sent out (that is bilingual, mind you) and the gentleman points out his water heater and says he needs propane in 'that' sigh...what makes this even worse is that, a week prior, he came in (same address, we remembered it d'oh) and we sent out a driver only to find the home all electric. He was not home for us to tell him that but apparently aware he'd not yet gotten a delivery, he came back, still trying to get gas. In his all electric home. Again...sigh...