For a home dweller there is more to going on vacation than making plane reservations and packing. Besides stopping the mail and newspaper, putting your lights and a radio on timers, notifying the police department and the alarm company and double-latching all doors and windows, there are several important considerations that have to be made. A home is packed with mechanical systems that can easily be damaged if left operating unattended. Think about it. There is the plumbing system, the cooling system, a gas and/or an electrical system, automatic appliances (frig, freezer, home electronics, garage-door opener). So, don't forget to turn off your main water and gas inlets, unplug hot-water dispensers and select a warmer operating temperature for your frig. And that's the On The House tip for today.