If only one faucet or shower has no hot water, the problem is usually a faulty valve, cartridge, or local plumbing issue—not the water heater.
Quick Answer
Start Here: One Fixture or More?
Single Fixture Diagnostic Table
Common Causes
Shower vs. Faucet Problems
How to Fix It
When to Call a Pro
Next Steps & Related Guides
FAQs
If hot water works everywhere else in your home but not at one fixture, your water heater is almost certainly fine. The issue is usually localized to that faucet or shower.
Quick Answer
No hot water at a single fixture is usually caused by a worn cartridge, faulty mixing valve, anti-scald setting, or a partially closed shutoff valve.
Start Here: One Fixture or More?
- Only one fixture affected: Local plumbing issue
- Multiple fixtures affected: See No Hot Water
Single Fixture Diagnostic Table
| What you notice | Likely cause | What to check |
|---|---|---|
| No hot water at one faucet | Faulty cartridge | Replace cartridge |
| No hot water in shower | Mixing valve or anti-scald setting | Inspect shower valve |
| Low hot water only | Clogged aerator or valve | Clean fixture |
| Problem started after repair | Valve partially closed or debris | Check shutoffs |
Common Causes
Faulty cartridge
A worn or clogged cartridge can block hot water flow at a faucet.
Shower mixing valve problem
A defective mixing valve can prevent hot water from reaching the shower.
Anti-scald setting
Many shower valves limit temperature. If set too low, hot water may not come through.
Partially closed shutoff valve
The hot water valve under a sink may not be fully open.
Debris or mineral buildup
Particles can clog small passages inside fixtures.
Shower vs. Faucet Problems
If the issue is in a shower, see:
No Hot Water in Shower
If the issue is in a sink, see:
No Hot Water in Faucet
How to Fix It
- Replace the faucet cartridge
- Adjust or replace the shower mixing valve
- Open shutoff valves fully
- Clean aerators and fixtures
When to Call a Pro
- You cannot access the valve
- Problem persists after basic fixes
- Multiple fixtures begin failing
Next Steps & Related Guides
FAQs
Why do I have hot water everywhere except one faucet?
This is usually caused by a faulty cartridge or valve in that fixture.
Why does my shower have no hot water but the sink does?
The issue is likely with the shower’s mixing valve.
Do I need to replace my water heater?
No. If only one fixture is affected, the water heater is not the problem.
