Plumbing Basics: FAQ

Q: Sometimes when I flush the toilet it keeps running until I jiggle the handle. What should I do?

A: It sounds as if the toilet flush handle gets stuck, causing the tank stopper to stay open. This allows the water in the tank to continuously flow into the bowl. Make an adjustment by oiling, tightening, or replacing the flush handle. See our “Fix-it Guide” for details.

Q: The hot water pipe to my kitchen sink is leaking. How do I make a quick repair?

A: To temporarily stop a small leak, break off a pencil point in the pipe hole and then wrap the pipe with three layers of plastic electrician’s tape, extending 3 inches on either side of the hole. You can also clamp a piece of rubber, such as an old rubber glove, over the leak. In another section of this Guide, we cover more on the topic of temporary patching. If it’s a major leak, though, turn off the water supply immediately at the main shutoff valve and replace the pipe

Q: When my washing machine shuts off abruptly, the water supply pipes make a loud banging noise. Is there anything I can do to stop this?

A: Water hammer (the noise you’ve described) occurs because the water in the pipes slams to a stop, causing a shock wave and a hammering noise. It’s not only annoying but also destructive to the pipes.

You can minimize or eliminate water hammer by installing air chambers—dead-end pieces of pipe. Most washing machine manufacturers recommend extra-long chambers—up to 24 inches—to pro vide added cushion for abrupt turn offs. Our article, “Connecting a Washing Machine,” will help you with this and related problems.

To learn how to install or restore (drain water from) an air chamber, see our “Noisy Pipes” article.

Q: I have an old brass faucet in my bathroom that I want to keep, but it constantly drips hot water from its spout. I’ve replaced the washer in the hot water faucet, but the spout still drips. How can I repair the faucet so it stops wasting my hot water?

A: A spout leak in a compression faucet like yours is caused either by a defective seat washer or a damaged valve seat. You can replace most valve seats with exact duplicates, using a valve seat wrench. If a worn valve seat can’t be removed, use a valve seat dresser to grind it until smooth.

Q: Should we use plastic or cop per pipe to install a new water softener in our system?

A: First check your local plumbing code on plastic pipe. Some areas don’t allow it at all, and others allow it for everything but drinking water supply pipes. If permitted, plastic piping can be a good choice, because it’s less expensive, easier to work with (to cut, join, and maneuver), self-insulating, and resistant to weather and corrosion. But be forewarned: Plastic pipe has its disadvantages, too. Before you make your decision, see our “Pipe-fitting Know-how” for complete details. Also, see our article on installing a water softener.

Q: What causes our water heater to make loud rumbling noises?

A: The two most common causes for such noises are steam and sediment in the tank (see “Water Heater Problems”). You can often correct steam problems by merely lowering the thermostat setting. If you suspect a faulty thermostat, turn the setting all the way down; then if the heat source doesn’t go off, replace the thermostat.

To get rid of problem-causing sediment in your water heater, open the drain valve at the bottom of the tank and drain off a little water until it runs clear. Draining the sediment should eliminate noise problems and allow your heater to operate more efficiently. For details on replacing a water heater, see “Plumbing Improvements.”

Q: We always have a soap ring in our bathroom sink because the pop-up stopper doesn’t open far enough for the water to drain out quickly. How do I adjust it?

A: If the stopper is so tight that the sink doesn’t drain properly, you’ll need to get under the sink to reset the pivot rod by squeezing the spring clip and inserting the rod in the next higher hole. Also remove the pop-up stopper and clean it periodically. Hair and debris can cause sluggish drainage.

Q: I need to cut a new piece of copper pipe for the supply run to my sink. What are the best tools and techniques to use?

A: It’s best to use a pipe cutter with a specially designed blade for copper pipe. You can also use a fine-toothed hacksaw, but making a straight cut with it's more difficult. After you’ve cut the pipe, clean off any burrs (inside or out) with a half-round file. See or topical articles for more details on copper pipe, including how to remove, measure, solder, and hang the pipe .

Q: Our friends have an instant hot water dispenser mounted on their kitchen sink. They say it conserves energy because it eliminates the need to boil water for tea, instant coffee, soup, and the like. Can I install one of these hot water dispensers myself?

A: You can do the plumbing and installation of most hot water dispensers in an afternoon, but unless you’re familiar with wiring techniques, leave the electrical hookup to a professional. The project involves attaching the dispenser faucet onto the sink rim or countertop, tapping into the cold water pipe with a saddle tee fitting, and mounting the hot water holding tank under the sink. For installation details, see “Plumbing Improvements.”

By the way, your friends are right about the dispenser being an energy-saver. See “Energy conservation tips” for additional information on energy-saving appliances and devices.

Q: I don’t really understand what makes a plumbing system work. The purposes of pipes to supply water and to drain waste seem clear enough, but what’s the purpose of vent pipes?

A: Plumbing works because of constant water pressure (about 50 pounds per square inch) in hot and cold supply pipes, the pull of gravity in drainpipes, and the balance of air pressure in vent pipes. Each fixture needs a vent to get rid of sewer gas and prevent a buildup of pressure in the pipes. To learn more, see “How Plumbing Works”.

Q: We want to add a second sink in the master bathroom. Can we extend the pipes that are already there?

A: Yes, you can. You’ll need to tap into the existing supply, drain, and vent pipes, run new piping to the desired location, and hook up the new fixture. For step-by-step instructions, see “Adding a second sink” and other articles with information on installing sinks on this web site.

Q: I’ve tried using a plunger and chemical drain cleaners, but my tub is still clogged. What else can I do before I resort to calling a plumber?

A: When working with water that contains chemical cleaners, use rubber gloves, bail out any standing water, don’t plunge, and avoid splashing.

For a stubborn clog, use a snake. Feed the snake down the drain or over-flow pipe to the trap to break up the blockage. If that doesn’t work, the problem is probably deep down in the main drain. For the next step, see our article on main drain clogs.

Q: Can you give me some advice before I replace a worn-out toilet with a new one?

A: Since a toilet is a major water guzzler in a home, choose one that conserves water (see “Water-conserving Fixtures”). Buy a toilet that’s ready to install, with flush assembly in place. Most important, carefully measure the roughing-in distance and select a new toilet that will fit properly in the space.

Actual installation takes a little muscle (lifting the old and new toilet off and on) and Sometime, but doing the job yourself can save you the high cost of a plumber.

Q: How hard will it be to plan and install a sprinkler system for my front yard?

A: It’s easier than you may think. The section “Exterior Plumbing” will guide you through the entire process. You’ll learn how to design the system, how to install all the necessary components, and how to maintain it in good working order. Although digging trenches can be tiring and hooking up valves and a timer can be tricky, the actual installation of pipes and sprinkler heads is simple, especially if you use plastic pipe. The same section also contains information on designing and installing tubing and emitters for a drip irrigation system, the most efficient method of watering plants.

Q: When the weather gets hot and humid, our toilet tank sweats so much that the floor tiles below the tank are starting to loosen. What can I do to prevent toilet tank condensation?

A: Before treating a sweating tank problem, be sure that a leak is not the culprit. To stop condensation on the tank, install a foam jacket (sold in hardware stores) or pieces of ½-inch-thick foam rubber inside the tank. You’ll need to empty the water from the tank before you glue the foam in place.

Another solution—though more expensive and involved—is to install a tempering valve.

Q: The trap under my kitchen sink has corroded through and started to leak. I’d like to replace it but don’t know where to start.

A: The hardest part of replacing a trap is loosening the couplings that are sometimes frozen in place on the old trap. Start by emptying the trap through the cleanout plug (if it has one) into a pail. Use a tape-wrapped wrench and counterclockwise force to remove the couplings at the tailpiece and drain pipe. Before installing a new trap, coat the threads of the connecting pipes with pipe joint compound or pipe-wrap tape to guard against leaks. “Trap Problems,” shows how.

Q: The water doesn’t drain out of our dishwasher. Any suggestions before I call for repair?

A: There are three common causes for standing water in the bottom of a dishwasher: a plugged strainer basket in the tub of the dishwasher, a dirty air gap, or a dirty hose loop that vents the appliance. Each is easily remedied—just clean out dirt, grease, or food buildup. To learn how, see our dishwasher chart.

Q: We’re considering adding an entirely new bathroom to our house. Can you let us know what to expect once we get to the plumbing part of this extensive project?

A: See “Roughing-in and Extending Pipe” before you start. This section outlines the planning process, code restrictions, venting options, and techniques for locating and exposing pipes, making pipe connections, running new pipe, and roughing-in fixtures.