DIY Q&A

Replace a crackling lightswitch

May 26, 2012 

Q: When I flip the light switches in my house, sometimes I hear a crackling, popping noise. Is this dangerous? Is new wiring required or is it something else? –Paul

The switches could be defective or worn out or the wires at the switch connections could be loose, causing arcing that is making the noises. There is probably nothing wrong with your basic wiring. Switches that make arcing noises can overheat, a definite fire hazard.

The safest course is to replace any switch that is making unusual noises such as hissing, crackling and popping. Switches are not expensive (avoid very cheap ones, since good ones cost only a few dollars each). Many switch replacements are made by do-it-yourselfers, although the wiring of some, such as three-way switches that operate a light from a couple of locations, can be a bit complicated.

The first step for any DIY electrical work is to turn off the current at the entrance panel. I never tamper with electrical wires without also testing them first with a circuit tester – an inexpensive tool with two probes and a light that glows if the wires are carrying current. When the electricity is off, remove the switch cover plate and the screws that hold the switch to the junction box in the wall. Grasp the sides of the switch and gently pull it out of the box. Don’t touch wires until you have tested them with the circuit tester.

Study the existing wiring before doing anything else – the location of these wires is a good guide to wiring a new switch. Simple, so-called single-pole switches might have only three wires – two insulated wires that carry current and a ground wire, which is sometimes not insulated. Note the positions of the wires and mark them with masking-tape labels if necessary. Loosen the screws that hold the wires in place. If the ends of the wires are damaged or nicked, cut off the damaged piece and expose about three-quarters of an inch of new wire. Some new switches have brass screws to attach the wiring – large screws for hot wires and a small screw for the ground wire. Wires are attached under screws by bending the ends into hook shapes and tightening the screws clockwise. Many new switches have small holes into which straight wire tips can be inserted to make the connections – a time-saving feature.

A couple of other tips: Most new switches are installed so they are “on” when the switch lever is in the up position. If a lever-type switch makes a single clicking sound when turned on or off, it is not necessarily defective; listen for other, more unusual noises before tossing out the switch. Finally, if in doubt about how to wire a switch, call an electrician – don’t try to muddle through.

Stop plumbing leak

Q: There is a slight leak around one of the nuts on a sink trap in my bathroom. The plumbing is old and when I tried to remove the nuts to replace the trap, they wouldn’t budge. I know it is best to replace the nuts, but I’m afraid of breaking other pipes. I have a pan under the trap now to catch the drip. Is there a way to seal the leak? I don’t want to pay a plumber. – EarlReplacing the trap nuts, washers or gaskets under them, and possibly the trap itself, is by far the best solution. Sometimes when a nut seems balky, you can apply enough pressure to loosen it by using force in the opposite direction on the same pipe. This requires two wrenches or pairs of adjustable pliers, one for the nut and one to grip the pipe. Paying a plumber isn’t a bad alternative, if necessary, when you consider that even a slight drip under a sink can cause severe damage to the floor.

But if you want to try and seal the leak, you can probably do so with a product called Goop, which is sold at many home centers and hardware stores in a toothpaste-type tube. I don’t recommend Goop for leaks in pipes where the water is under pressure, such as your water supply pipes. However, the trap under a sink is normally not subject to great water pressure, just the water running out of the sink.

Goop is sticky and much like thick glue. It has a rubbery consistency when dry. Lightly sand the area where you will put the Goop and wear plastic gloves while applying it. The surface must be dry and clean and you must give the Goop at least 24 hours to set up. Spread a bead of Goop all around the nut. Goop can generally be scraped or picked off with the point of a knife if it eventually becomes necessary to remove the nut. Keep the tray under the leak area for a week or more until you are sure the leak is stopped, then check periodically for leaks. A more permanent – and much more difficult-to-remove repair material – is epoxy putty, which dries rock hard and can frustrate even a plumber.

Questions and comments should be emailed to Gene Austin at gaus17@aol.com. Send regular mail for Gene Austin to 1730 Blue Bell Pike, Blue Bell, PA 19422.

McClatchy-Tribune News Service

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