You can check your bathroom for leaks in 30 minutes with food coloring and a utility bucket.

Check the toilet.

• Put a few drops of food coloring in the tank and wait 30 minutes to see if the color appears in the bowl. If it does, the toilet might have a leaking flapper valve. Flapper valves are easy to install and are available at most hardware stores.
• Look at the back and bottom of the toilet for leaks on the supply line.

Check the sink.

• Watch the faucet for a minute for drips.
• Open the cabinet and check the hot and cold supply lines for weak spots, such as a bulge in the hose.
• Turn on the faucets and watch the lines for leaks while they are in operation.

Check the bathtub and shower.

• Operate the faucets to make sure they function properly.
• Turn on the shower to check for leaks. When the water is diverted to the showerhead, the water flow from the tub faucet should stop.
• It is difficult to check the exact flow from your aerators and showerheads without the proper flow bag (a plastic bag with measuring marks on the side). But if you have a utility bucket you know the capacity of, you can time filling it to determine the approximate flow.
• If the showerhead and aerators have been on for a while, they might need to be changed. High-efficiency showerheads and aerators are available at any hardware store and are easy to install.

Check all water sources for leaks, following the instructions for bathrooms.

• Sink faucets
• Dishwasher
• Garbage disposal
• Ice maker

Check all water sources for leaks.

• Supply lines to washing machine
• Supply lines to sinks

If you have additional water sources in your house, thoroughly check them using the same procedures. Be sure to fix all leaks as soon as possible.