Q I inherited a stamp collection from my aunt. Is there any reasonable way to find out something about it? I think she spent money building up the collection, but I don't know for sure.

A The approximate value of any individual stamp can be obtained from a stamp catalog, according to the American Philatelic Society. Find a catalog at your local library or bookstores. Or you could ask a dealer. For example, Bill Norberg of Golden Valley Stamps & Coins said he offers a free 10- to 15-minute appraisal. Call 763-544-4431.

Electric water heater Q Is it better to leave an electric water heater on when not in residence for a week or two, or to shut it off? Does it cost more to heat it up each time or to continually heat it when it is not in use?

A Off is always preferred. Heat always moves to cold. And because we keep the water warmer than our home's air temperature, standard water heaters let loose lots of heat in the home. The amount of heat lost is determined by the temperature difference and how well the water heater is insulated.

By turning off the water heater, the temperature within would drop to the same temperature as the air in the home. No need to use relatively expensive electricity to heat your home!

Also, consider turning off the circuit breaker serving the electric water heater so it is off while you're gone. You will save some money, energy and associated carbon emissions.

Phil Smith, Minnesota Office of Energy Security

Send your questions to Fixit in care of the Star Tribune, 425 Portland Av. S., Minneapolis, MN 55488, or call 612-673-7032, or e-mail fixit@startribune.com. Past columns are available at www.startribune.com/fixit. Sorry, Fixit cannot supply individual replies. Fixit appears every day except Friday.