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Install a High Efficiency Toilet

Save up to 65 percent of this water by installing a high efficiency or dual flush toilet.

Toilet flushing can account for up to 30 percent of household water use. High efficiency toilets use 4.8L of water or less per flush. Typical dual flush toilets use either 3L or 6L per flush. All Eco Options approved toilets meet this high efficiency standard.

You'll install a new high efficiency toilet in two steps - first the bowl, then the tank. The most difficult part of the installation will be putting the bowl in place. It's heavy, and you'll have to place it so the floor bolts are directly lined up with the holes in the toilet base. When working with heavy porcelain items such as toilets, avoid banging them into anything. Porcelain is tough - up to a point. If it cracks, it can't be used.


  •  There are 14 steps to completing this project:
    Step 1  Preparation
    Step 2  Set the mounting bolts
    Step 3  Place the wax ring on the toilet
    Step 4  Set the toilet bowl
    Step 5  Tighten the nuts
    Step 6  Cut the flange bolt to size
    Step 7  Install the bolt cap
    Step 8  Set the tank anchor bolts
    Step 9  Place the tank on the bowl
    Step 10  Tighten the tank bolts
    Step 11  Install the shutoff valve
    Step 12  Always replace the supply tube to help prevent leaks
    Step 13  Connect the supply pipe to the tank
    Step 14  Tighten the compression nut

  • Toilet
    Toilet Seat
    Wax ring
    Floor Bolts
    Mounting Nuts

  • Ratchet Wrench and Socket
    Adjustable Wrenches
    Mini Hacksaw

1  Preparation

Turn off the water supply at the shut off valve and plug the drain opening with a rag to keep sewer gases in the pipes.

2  Set the Mounting Bolts

If you're reusing the old flange, replace the 3½-inch flange bolts. Purchase two 3½-inch-long closet bolts at your local Home Depot. If you're replacing the flange, it must be screwed into a wooden floor. Use self-tapping concrete screws for concrete. Closet bolts often tip over when you're trying to place the toilet. Put an extra nut on each bolt, and tighten it against the flange to hold the bolts in place.

3  Place the Wax Ring on the Toilet

The "no-seep" wax ring size will vary with the size of the flange. Be sure to purchase the proper size. A 3-inch neck will fit a 3-inch closet elbow, and a 4-inch neck will fit a 4-inch closet elbow. If the closet elbow is 4 inches and the neck is 3 inches in diameter, purchase a 4X3 reducer. If the flange is positioned below floor level, buy a double-thick ring.

4  Set the Toilet Bowl

Straddle the toilet bowl and lift, using your legs - not your back. Toilets are heavy, so get some help. Set the toilet over the anchor bolts and sit on the toilet, rocking it back and forth to seat the wax ring. Slip a washer over the closet bolt.

5  Tighten the Nuts

Tighten the nuts against the washer by hand. With a wrench, tighten each nut a half-turn. Alternate tightening each side a half-turn until the toilet fits snugly. Tightening either side too much will cause the toilet to crack. If the toilet rocks or isn't level, shim it with plastic toilet shims, and cut the ends off, so they won't be seen.

6  Cut the Flange Bolt to Size

Use a mini-hacksaw to cut the flange bolt so only ¼ to ½ inch extends above the bolt. This will allow the cap to fit snugly. Most bolts have snap-offs every ½ inch or so, but you should still cut through so you don't bend the bolt.

7  Install the Bolt Cap

Some types of caps will snap over the bolt. Others have to be filled with plumber's putty and seated over the anchor bolt.

8  Set the Tank Anchor Bolts

Place the tank anchor bolts in the holes of the tank to help guide the tank onto the bowl. Note: Most tank bolts come with a rubber washer, a metal washer, and a nut. The rubber washer goes on the inside of the tank, and the metal washer goes next to the nut on the underside of the bowl.

9  Place the Tank on the Bowl

Lift the tank and place it over the bowl. You may need some help with this. Guide the tank bolts into the corresponding holes on the toilet bowl.

10  Tighten the Tank Bolts

Hold an adjustable wrench over the tank bolt nut while you tighten the bolt with a screwdriver. Don't over tighten; you can crack either the tank or the bowl.

11  Install the Shut Off Valve

Set the valve over the compression ring and draw the nut to it. Tighten the nut until hand-tight. Use two adjustable wrenches to tighten until snug - one to hold back the valve and the other to tighten the compression nut.

12  Always Replace the Supply Tube to help Prevent Leaks

Screw flex tube in place. If you're putting in chrome tube, hold it in place with the extra pipe extending past the shutoff. Mark the pipe for cutting. Leave enough pipe so it will fit inside the shutoff valve outlet. Cut with a tubing cutter.

13  Connect the Supply Pipe to the Tank

Seat the end of the pipe against the tank. Draw up the tank nut and hand-tighten until snug. Slide the compression nut over the other end, then place the compression ring over the end. Seat the end in the outlet of the shutoff valve.

14  Tighten the Compression Nut

Use an adjustable wrench to carefully tighten the compression nut. Don't over tighten. Turn on the water supply and check for leaks along the supply line, visually and by feel. Flush the toilet and check for leaks around the base of the tank. If there is a leak, tighten the connections a half-turn.