How To Replace A Toilet Supply Line

Posted on: 16 June 2015

If your toilet supply line is leaking at a connection or anywhere along its length, it is simple to replace. The only issue you may experience is contorting your body to reach it, if your toilet is located in a corner where access is limited.

You will need to call plumbers if you have back problems or can't change the supply line yourself for any reason, because water supply lines are pressurized, and could burst if sufficiently compromised by age or other causes. A leaking supply line must be repaired or replaced. If you are physically able to do the job, it should take less than thirty minutes:

What you will need:

  • A new supply line

You will need to buy either a plastic or stainless steel flexible supply line. Either material is acceptable, but a plastic supply line can be punctured more easily. A stainless steel supply line is a little more expensive, and not quite as flexible. 

You must be sure to buy the correct size, in both length and diameter. The length doesn't vary too much, but it must reach from the floor to the bottom of the toilet. Longer lengths are okay, because it is a flexible material,  but getting one too short will be a problem.

The diameter will usually be either one 1/2 inch or 5/8 inches. If the old supply line isn't marked, take it with you when you go to buy the new one.

  • Pipe tape.

This is a thin roll of plastic ribbon used for sealing pipe threads.

  • An adjustable wrench

How to remove the old supply line

You will first need to turn off the water supply by turning the valve below the pipe clockwise until it is fully shut. You will then drain the toilet bowl by flushing the toilet, then removing all excess water with rags or paper towels until it is dry.

Using your adjustable wrench, turn the connecting nuts on the top and bottom of the old supply line counterclockwise until they are completely loosened, then remove the old supply line.

Installing the new supply line

You will first need to cover the exposed threads on the pipe coming from the floor and the connection on the bottom of the toilet. Wrap pipe tape around each threaded connection in a clockwise direction until all threads are covered. this will help to prevent leaks at the connections.

Hand tighten the nuts on each end of the new supply line onto the threaded connections in a clockwise direction, then tighten them with the adjustable wrench.

Turn the supply valve counterclockwise until it is fully open, and you're finished.