Quick Answer:
If your shower only delivers hot water, don’t panic. First check whether cold water is available at other fixtures. If cold works elsewhere, the problem is likely inside the shower valve — a misaligned handle, an anti-scald setting, a blocked cold inlet, or a failed cartridge. If cold is off everywhere, verify shutoffs and the main supply.
Why This Happens
- Shower valves mix hot and cold. If the cold side is blocked or the valve’s cold port is closed, you’ll get only hot water.
- Anti-scald devices or limiter stops inside the valve can be set or failed, restricting cold flow.
- Cartridge or pressure-balancing parts wear or fail, allowing only hot through.
- Supply-side issues — a closed or stuck shutoff, or a closed service valve — will cut cold water to the fixture.
Step-by-Step What to Do
Step 1 — Test cold water at other fixtures
- Turn on a cold tap at the bathroom sink, kitchen sink or an outside hose bib. If cold is available there, the issue is most likely limited to the shower valve.
- If cold is not available anywhere, skip to the shutoff checks below.
Step 2 — Check shower handle alignment
- Look at the handle position when you expect cold. Some handles have a visible center or detent for cold; if the handle is off-center it may not open the cold port fully.
- Do not force the handle — if it’s stiff, it could be seized or damaged.
Step 3 — Inspect anti-scald / stop settings
- Many modern valves include a temperature limit stop or anti-scald device. Remove the handle or trim plate per the manufacturer’s simple instructions and check for a limiter that’s been shifted.
- If the limiter is set incorrectly, you may be able to reposition it to restore cold flow. If unsure, stop and call a pro.
Step 4 — Consider cartridge failure or cold-side blockage
- If the cold side is mechanically blocked (mineral buildup) or the cartridge’s cold inlet has failed, the valve will deliver hot only. Replacing or cleaning the cartridge often fixes the issue.
- If you’re comfortable with basic DIY and have the correct replacement part, you can remove and inspect the cartridge. Otherwise, plan to call a plumber.
Step 5 — Verify cold supply and accessible shutoffs are open
- Check any local shutoffs near the shower or under nearby sinks. Make sure they are fully open.
- If you suspect a service-side problem, locate and confirm your **main water shutoff valve** is fully open. If the home’s cold supply is off or restricted, that will affect the shower.
- If a supply valve feels jammed or damaged, the issue could be a **shutoff valve stuck or broken** and may need professional repair.
What Not to Do
- Do not force the handle.
- Do not keep running scalding water.
- Do not assume it will fix itself if it started suddenly.
When to Call a Professional
- Call a plumber if cold water is available elsewhere but the shower stays hot after you checked handle alignment and limiter settings.
- Ask for help if you find mineral buildup on the cartridge or suspect internal damage — cartridge replacement or valve repair is often best handled by a pro.
- Call immediately if you cannot access or safely operate shutoffs, or if the valve appears corroded or leaking.
Safety Notes
- Hot water can scald quickly. Stop using the shower until you can control temperature safely.
- Turn off water at the nearest accessible shutoff before removing trim or cartridge parts. If you can’t find a shutoff, stop work and call a plumber.
- Avoid makeshift fixes that expose plumbing to leaks or further damage.
Common Homeowner Questions
- Q: Why would cold stop suddenly?
A: A sudden stop often points to a closed shutoff, a failed cartridge, or a blockage from debris or mineral build-up. - Q: Can I replace the cartridge myself?
A: Many homeowners can do it if they have the right part and tools, but stop and call a pro if you’re unsure or water cannot be shut off safely. - Q: Is it dangerous to keep using the shower?
A: Yes — risk of scalding is real. Avoid using the shower until the temperature control is restored or you can limit hot flow safely.