An expert can tell you if the proper-gauge wire is serving each room. It's also important to have enough outlets and switches, conveniently placed. Plumbing system Look closely at the condition of the pipes. Copper and brass pipes are best, but you may find some of galvanized steel, iron, or plastic. New sections of pipe may signal that other replacements will soon be needed.
Good systems have more than one shutoff valve.
Clean out plugs should be conveniently located. If the furnace uses gas, watch out for clogged burners. In oil furnaces, the fittings and tank should be in good condition, with no soot around registers. In electric systems, check the blower. The age and physical appearance of any heating system helps you gauge its worth.