Inspectors disagree about aluminum wiring
Q. My home has aluminum wiring. In one of your articles, you recommended copper pigtails on the wire ends to eliminate a fire hazard. So I called my local building department to get their advice. The building inspector I spoke to is a retired electrician who became a county building inspector. He told me that aluminum wiring is safe as long as it is not overloaded and that connecting aluminum wire to copper "pigtails" is not advisable. He said the only way to eliminate the hazards caused by aluminum wire is to completely rewire the house. With two conflicting opinions, who do I believe?
A. It is surprising that a professional building inspector and former electrician would be unaware of aluminum wire issues and the accepted method of correction. This has been widely recognized within the electrical profession for many years.
The use of aluminum wiring for 110-volt circuits was totally discontinued by the building industry in the early 1970s because many house fires were caused by faulty aluminum connections. Aluminum wire ends can become loose, causing them to overheat. The standard procedure to eliminate this problem is to add special copper ends, commonly known as "pigtails," at each of the outlets, switches, lights and other fixtures. There is no need for rewiring because the problems associated with aluminum wires only occur at the connections. For confirmation of this opinion, consult any reputable electrical contractor, or call the local electricians union and speak to the person in charge of apprenticeship.
Q. My plumber recommended that I drain my water heater at least twice a year. But I'm on a well and don't like to waste water, so I stopped doing it about two years ago. Since then, my water heater has made loud knocking sounds when the burner is on. When I used to drain the tank, a light gray granular substance would come out with the water. What is that stuff, and what do you recommend with regard to draining water heaters?
A. The cold water that enters your water heater contains particles such as silt, gravel and various minerals, especially if you have well water. These particles settle to the bottom of the tank and should be flushed out periodically to maintain the water capacity. If you don't flush them out, they accumulate and cause flash boiling when the burner is ignited, which is why you hear the knocking sound. If you leave the sediment for years, it tends to become a hard lump and can no longer be flushed out.
To see what flash boiling looks like, put 1 to 2 inches of sand in a pot of water, place the pot on your stove, and turn on the heat. As the water beneath the sand becomes hot, you'll see erupting bubbles of steam, just as they occur in your water heater.
Flushing your water heater about twice a year is a good practice. If this seems to be a waste of water, then flush it into a five gallon bucket, and use the water to irrigate your garden.
• E-mail questions to Barry Stone through his Web site, housedetective.com, or write AMG, 1776 Jami Lee Court, Suite 218, San Luis Obispo, CA 94301.
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