Why does my shower faucet leak when the water is off?

You may not even notice it at first, then you can’t stop hearing it, and then it can seem deafening. It’s the drip, drip, drip of a leaky shower or tub faucet.

Not only can a shower leak get really annoying, but it can also cause significant damage that can be expensive to remedy. It’s important to fix the leak as soon as you notice it, to minimize the damage. A shower valve that is leaking inside the wall is hazardous and can cause rot, mould, and structural problems.

A leaking shower faucet is also wasteful of water and electricity; if the hot water is leaking it forces the water heater tank to be continuously running. If water is left to accidentally run, it can waste up to 15,000 litres of water per month, which can cost up to $1200 a month.

What causes a leaking shower faucet?

The number one culprit of a shower drip or drizzle is a problem with the shower faucet valve. The parts of a shower valve break down over time and with use. The seals and gaskets become worn down and the inner parts can become clogged and corroded from minerals in the water. This is especially true if you live in a city with hard water.

And don’t think that a really tight crank of the handle will stop a leak, as overtightening can cause additional damage to the valve.

The good news is that you can replace or rebuild a leaking shower faucet valve all by yourself in less than an hour. And if you’re having troubles, we’re only a quick phone call away.

To fix a shower valve leak, you’ll need to gather a few tools and equipment. For doing this repair work you’ll likely need the following:

• Small flathead screwdriver
• Allen wrench
• Phillips-Head screwdriver
• Rubber strap wrench
• Masking tape
• Flashlight
• Pencil
• Replacement valve or new gaskets and grommets
• Cleaning supplies: scour pad or brush, vinegar

How to repair or replace a shower valve

Turn off the water supply
The first step is always to turn off the supply of water to your shower and tub. Some homes have a shut-off in the washroom, usually near the shower, or in the basement. Otherwise, the water for the whole house must be turned off.

Drain water from pipes
Open the washroom sink faucet and let the water drain out from the nearby pipes connected to the shower.

Protect the area
To protect the surfaces of the tub and shower, as well as prevent small parts from being dropped down the drain, place rags in the tub beneath the faucet and over the drain.

Remove the handle and trim of the shower faucet
The first step to dismantling your shower faucet is to remove the handle. How you’ll do this will depend on the make and model of your faucet. Some will need a small flathead screwdriver to pry off the handle. Other faucets have a small Allen bolt that can be unscrewed from underneath the knob. Use a Phillips-Head screwdriver to unscrew the outer plate of the faucet to remove.

Remove the valve collar
Once you’ve removed the faucet handle and trim, you’ll see a shiny collar that rests over the valve. Remove this but ensure that you leave the rubber gasket underneath.

Remove the valve bushing
Now you’ll see there is a large brass bushing, or bearing, that holds the valve in place. Use a soft rubber strap wrench, if you have access to one, as it’s the safest to use due to it being able to grip the bearing well. Tighten the strap of the wrench around the brass bushing and crank it gently to the left.

Water will likely pour out as the pressure behind the valve releases. Slowly unscrew and gently remove the brass bushing, as there are springs resting behind the valve that have to remain.

Remove valve and seals
Slowly remove the faucet valve. Using a flashlight, look inside the valve body looking for two holes where the water comes out — one for hot and one for cold. Make note of, or label, which is for hot water.

Using a pencil, remove the small gasket and set of grommets with springs inside each of the cold and hot water holes. Then use the pencil to gently remove the outer gasket.

Replace or rebuild your faucet valve
Now it’s time to take a look at your valve — is it in good shape? Or highly corroded? If the valve is fairly new or in good condition, you can choose to just install new gaskets and grommets.

But if the valve has corrosion and since you’ve already opened everything up, it’s best to replace the whole valve. Take the old valve to a hardware store and purchase a new one, ensuring the brand and model match.

Get all the pieces squeaky clean
While you had the faucet and valve disassembled, it’s a good idea to do a quick clean of the parts to clean off the calcium and mineral buildup. Using a scouring pad or brush with some vinegar to scrub the valve stems, springs, seals, filter cones, and discs.

Put it all back together again
To reassemble your faucet and get back to showering, do the installation in the reverse of how you took it apart. First, use your pencil to push the grommets and springs into the valve holes, holding the valve in place. Ensure the side of the valve labelled for the hot water is oriented to the correct position. Give the brass bushing a twist with the strap wrench, then turn on the water. Test out both the cold and hot water by twisting the valve stem by hand. Let the water completely stop dripping before moving on to the next step.

Re-install the trim and handle
Push the collar back over the valve body, make sure the rubber gasket is kept underneath to prevent water leaks from going into the wall. Screw the wall plate back into place and then re-install the faucet handle. You’re done!

If you need support, we’re here

Plumbing Paramedics is family-owned and operated right here in Calgary. We have extensive experience in shower valve replacements and would be happy to do the work for you at a high level of quality. To ensure that you have complete confidence of mind, we also offer a 12-month warranty guarantee.

Have you fixed a leaking shower faucet before? What worked best for you? If you have any questions or comments about this repair job, please post them in the comments below.