Y2K technology marches on. It brings wonderful new household appliances such as space-age microwave ovens with radio waves that penetrate food and jiggle molecules around. This causes heat inside that cooks food without external heat or flame. It’s great new stuff that we'll soon get used to and begin taking for granted. But, microwaves were introduced in the early '70s. Today many are 15, 20 or even 25 years old and still being used on a daily basis. As microwave ovens age, remember the words -- efficiency and safety. First, make sure yours still delivers full power for proper cooking. One cup of water should boil within 3 minutes. If that's not the case, have it checked. A dirty interior also can cut efficiency and strange noises, electric arcing and a flashing display signify it’s time for a checkup. If your unit is more than 15 years old, have it tested for radiation leaks by a professional technician. And that's the On The House tip for today.