Plumbing tips · October 28, 2026
A cold shower nobody ordered
If the sinks have hot water and the shower does not, the water heater is not the problem. The shower valve is.
Check the rest of the house first
Turn on the hot water at a bathroom sink and the kitchen sink. If they get hot and the shower does not, look at the shower valve. If nothing in the house gets hot, start with the water heater.
The cartridge
Most single-handle showers mix hot and cold inside a cartridge behind the handle. Hard water scale and grit can jam it so it stops moving to the hot side, or lets only one side through. A new cartridge made for that valve usually fixes it.
The temperature limit stop
Many shower valves have a plastic limit stop under the handle that keeps the water from getting too hot. If it is set too far toward cold, or slipped when the handle was off, the shower never gets past warm. It can be turned a notch or two hotter.
When it scalds instead
A shower that runs too hot, or jumps hot when someone flushes, has a pressure-balancing part that is not doing its job. Have the valve looked at rather than turning the handle down and hoping.
Questions we get asked
Why does my shower get hot and then go cold?
If it happens in every faucet, the water heater may be running out or have a bad element or burner. If only in the shower, the valve cartridge is the likely cause.Why is only the shower cold after a new water heater?
The water heater cannot make one fixture cold. When the sinks run hot and the shower does not, the shower valve or its limit stop is the place to look.Can I turn up the water heater to fix it?
Turning the heater up rarely fixes a shower valve problem and makes the sinks hotter than they need to be. Check the valve and the limit stop first.Plumbing questions we answer
Where we go
Parker, Wise and Tarrant County, out of the shop in Springtown. Springtown, Weatherford, Azle, Boyd, Decatur, Newark, Millsap, Fort Worth and the country in between.
Call 817-487-8866