Why Does My Shower Leak?

Steve St. Louis • October 28, 2026

Quick answer


A shower that drips after you turn it off, jumps between hot and cold, or has a stiff handle usually has a worn cartridge inside the shower valve. Replacing the cartridge fixes most leaky showers without changing your trim or tile. Water stains on the ceiling below or loose tiles are a different story: that can mean a hidden leak inside the wall.



Why showers leak

Shower faucets come in a wide variety of shapes, styles and sizes. But no matter what type you have, any shower faucet can start to leak or struggle to hold a temperature over time.


Behind the handle and trim plate is the part that does the real work: the shower valve, and inside it, the cartridge. The cartridge controls how much water flows and mixes the hot and cold.


Over time, its rubber seals and moving parts wear out, and minerals from Edmonton's hard water build up. That's when the drips, temperature swings and stiff handles start. A dripping shower isn't just annoying: it can waste thousands of litres of water a year.



Infographic on how to tell a dripping shower from a hidden leak, with a blue and orange checklist.

What you can safely check yourself


  • Where is it dripping? From the shower head after it's off usually means the cartridge. From the handle or trim plate can mean a worn seal.
  • Caulking and grout: look for gaps or cracks around the tub, tile and trim plate where water can get behind the wall.
  • Shower head: if water sprays from the connection, unscrew it and re-wrap the threads with plumber's tape.
  • The ceiling below: check for stains, bubbling paint or soft spots.
  • Water meter test: turn off every tap, note the meter reading, and check again in an hour. If it moved, water is leaking somewhere.


White slide with orange border and text: “Most leaky showers need a new cartridge, not a new shower.”

Water near anything electrical? Turn off the water first, stay out of it and don't touch switches or light fixtures. If water is coming through the ceiling below, turn off your main water shut-off and call right away.

When to call a professional


Call a licensed plumber if:


  • The shower keeps dripping after you've turned it off firmly
  • The temperature swings or the handle is stiff
  • You see water stains on the ceiling below the bathroom
  • Tiles are soft, loose or cracked, or paint is peeling near the shower
  • You notice a musty smell that won't go away


How SS Plumbing & Heating handles it


We find where the water is actually coming from before we open anything. Most of the time it's the cartridge or valve, and we can replace it the same visit while keeping your existing trim and tile right where they are. We'll give you a clear price before we start.


If the leak is hidden inside the wall, we'll track it down with as little damage as possible and explain your options.


A Few Questions We Get a Lot


Do I need a whole new shower to fix a leak? Usually not. In most cases, a new cartridge or valve fixes the problem and your trim and tile stay put.


Is a slow drip really worth fixing? Yes. It wastes water, adds to your bill, and the worn part usually gets worse. Hidden leaks can also lead to mould and costly damage. See Found a Leak? What to Do First.


Why does my shower suddenly go cold? It can be a worn cartridge, or your hot water tank may not be keeping up. If every tap runs out of hot water fast, read Should I Repair or Replace My Hot Water Tank?

Got a dripping shower?


Call or text us, or send a photo of your shower handle and trim. We'll tell you what we're likely looking at before we come out.

About Steve

Steve St. Louis is a Red Seal Journeyman Plumber and Gasfitter (Class B) and the owner of SS Plumbing & Heating Ltd. Based in Sturgeon County, Steve and his team have served Edmonton and area since 2020, with 24/7 emergency service and a 5.0 rating from 450+ Google reviews.