Signs your valve needs attention
- The shower drips after you turn it off.
- Somebody flushes and you get a blast of hot or cold.
- The lever binds, or must travel most of its arc before warmth arrives.
- The water never gets hot enough, even with the tank working.
- The tub spout still runs when the diverter is pulled.
Types of valve
| Valve | How it controls temperature |
|---|---|
| Pressure-balancing | Keeps the hot-cold ratio steady when pressure changes |
| Thermostatic | Holds a set outlet temperature |
| Older two- or three-handle | Separate compression valves for hot and cold |
Ontario requires anti-scald protection on showers, which most modern pressure-balancing and thermostatic valves provide.
The visit, in order
- 1
Close the stops, open the tap to relieve pressure and cover the drain opening.
- 2
Remove the handle, trim and cartridge or the whole faucet body.
- 3
Seat the new parts, reconnect supplies and seal the drain flange.
- 4
Run hot and cold, check every joint with a dry tissue and clear the trap.
How we repair it
- Shut off water at the valve's integral stops or at the house main.
- Remove the handle and trim plate to expose the cartridge.
- Extract the cartridge, using a puller if scale has seized it.
- Clean the valve body and fit a new genuine cartridge.
- Set the rotational limit stop so the hottest setting is safe, then test.
When the wall must be opened
Should the brass body split, or a sweated joint behind it weep, we need access. We prefer to open from the back if there is a closet or panel behind the shower, which avoids damaging tile. Where there is no other route, we discuss options before cutting anything.
For a full update, see bathroom plumbing renovation, and read fixing shower temperature swings for background. Low flow from the head is often scale; our hard water guide explains why.
Markham note: village-core houses tend to hide cast iron and galvanized behind plaster, while Cornell and Box Grove builds run PEX to a manifold. We ask the year your house was built so the right fittings ride along on the truck.
Straight from the phone log
Why is my shower only lukewarm?
Often the limit stop on the valve is set too low, or the cartridge is worn. Both are adjustable or replaceable.
Can I replace the trim only?
Only with trim made for the same valve body. Mixing brands rarely works.
Ready to get it fixed?
One call, a clear explanation, and work finished tidily before we leave.