A faulty water heater is a time bomb ticking away in your home. When pressure builds in a 30-gallon water heater due to a broken temperature-and-pressure-relief valve, it can explode with the consequences of 2 pounds of dynamite. Experts also report one-third of all water heater temperature-and-pressure-relief valves are not operational due to mineral buildup, rust or corrosion. Yours should be tested every six months. What is the temperature-and-relief valve, where is it and how does one test it? It's that little lever on top of your water heater. If it won't budge with normal hand pressure, tap it lightly with a hammer to loosen it. If it then leaks, open and close it several times to dislodge any debris that might keep the valve from closing properly. If you can't stop the leak, replace it. Frequent tests will prevent future leaks by keeping the valve clean. A clean valve in good working order is a must. And that's the On The House tip for today.