If your shower has no hot water, turn on the hot tap at a bathroom or kitchen sink. If the sink runs hot, the water heater is fine and the fault is in the shower valve or cartridge. If the sink is cold too, the heater has stopped, run out, or is not reaching that part of the house. This one test saves most of the guessing. The rest of this page follows each answer, from checks you can do in ten minutes to the point where a plumber should come. If the whole house is cold, start from our water heater repair and replacement page.
What does shower no hot water mean for your home?
It means one of two things. If hot water works at the sinks but not the shower, the shower valve is blocked, worn or set wrong. If no tap in the house gets hot, the water heater has failed or run out. The sink test separates them in under a minute.
Run the sink for a couple of minutes, because in a long house with pipes far from the heater, hot water takes time to arrive. If it never turns hot, the heater is the issue. If it turns hot at the sink but the shower stays cold or lukewarm after several minutes, the shower is the issue. Plumbers start from the same split, and your repair is based on which side you land.
Why is there no hot water in the shower when the sink is hot?
The usual causes are a worn or scaled mixing valve cartridge, a shower valve stuck in the cold position, a blocked inlet screen, or an anti-scald limit stop set too low. Scale from hard water builds up inside cartridges, and in cooler months the valve needs to open further to give the same temperature.
The fixes run from easy to harder:
- Take off the handle and look for the plastic limit stop behind it. Rotate it to allow more hot water.
- Check and clean the inlet screens on the valve if they are accessible.
- Replace the cartridge, which is a common repair, using the maker's part for your valve.
- If a new cartridge does not fix it, call a plumber, because a crossed or failed supply inside the wall needs opening up.
LADWP classes water above 7 grains per gallon as hard, and its 2022 averages ran from 8.6 grains in the Valley and West Los Angeles to 16.3 in the east and the harbor area. Scale clogs small passages in a shower cartridge sooner than anything else in the house.
A shower that has gone cold only after a remodel or a valve change can also have hot and cold supplies swapped. A plumber can check that.
What if no tap in the house has hot water?
Then the water heater is the cause. On an electric unit, look for a tripped breaker or a failed element or thermostat. On a gas unit, look for a pilot that has gone out or a failed thermocouple. A tankless water heater may show an error code. A tank that is old or leaking may need replacing.
Check the basics in this order, and stop if anything feels unsafe:
- Electric tank: check the breaker and the reset button on the thermostat cover. Do not remove covers with the power on.
- Gas tank: look at the pilot. If you smell gas, leave the building and call SoCalGas on 1-800-427-2200 from outside, and call 911 if there is immediate danger. If the pilot is out and you are not sure how to relight it safely, see our water heater pilot light repair page or call a plumber.
- Tankless: read the code on the display, and see instant water heater repair.
Our guide on why you have no hot water covers each of these in more depth.
Why does the shower go cold after a few minutes?
A shower that starts hot and fades usually means the heater cannot keep up, because the tank is too small, sediment is reducing its capacity, or an element has failed so only part of the heating works. Another cause is a second tap or appliance drawing hot water at the same time.
A tank holds a fixed amount of hot water, and once the hot is used the incoming cold water cools what is left. A sediment layer at the bottom of a tank, which is common in hard water areas, cuts the heating capacity, and a failed lower element on an electric tank leaves only the top half working. Both are repairs a plumber can check. A tank heater that keeps getting colder over a few years is also worth a look for water heater replacement, particularly past its normal life.
Why is the shower lukewarm in winter?
Colder incoming water in winter means the shower valve and the heater both have more work to do. An anti-scald limit stop that felt fine in July can leave a January shower lukewarm, and a heater thermostat set low has less to spare. Raising the limit stop a little, or the heater setting within safe temperatures, often fixes it.
Do not raise the heater temperature past what is safe for your household. A very hot setting risks scalds, especially for children and older people. The valve's limit stop and the heater's temperatures work together, so adjust one step at a time and test.
When should you call a plumber for a shower with no hot water?
Call when the cartridge swap does not fix it, when the valve is behind a wall with no access, when the heater is gas and the pilot will not stay lit, when a breaker keeps tripping, or when any smell of gas is present. Gas, wiring and wall work belong to a plumber with the right California contractor license.
We can arrange a local plumber to come to your home, run the sink test again, find the cause and give you a written quote before any work starts. Use our quote page and say what happens at the sink and what happens in the shower, so the visit starts at the right place. If the shower is also leaking, see plumber for shower leak. The home page lists the other jobs we arrange across Los Angeles.
Common questions
How long does it take to fix a shower with no hot water?
A cartridge swap or a limit stop adjustment can take under an hour. A water heater fault takes anywhere from an hour for a simple part to a day for a replacement, and a replacement in the City of Los Angeles also needs a permit. A plumber can give a time estimate after the first look.
What should I ask before I hire someone for a shower with no hot water?
Ask whether the quote covers diagnosis and the fix, who supplies the parts, and what happens if the fault turns out to be something different. Ask for their California contractor license number and check it with the state board. Ask for the price in writing before work starts.
Does someone need to be at the property?
Yes, someone should be there so the plumber can reach the heater, the shower and the shut-off valves, and so you can see the problem solved. The water or power may be off for part of the visit. Tell the plumber about anyone who needs hot water that day.
Why do I have hot water at the sink but not the shower?
The shower valve or its cartridge is the cause, not the heater. Scale, a worn cartridge, a stuck mixing valve or a limit stop set too low stops hot water reaching the shower. Adjusting the limit stop or replacing the cartridge usually solves it, and a plumber can do either.
Is no hot water an emergency?
Usually no, unless there is a gas smell, a leak or a burning smell. Cold showers are a nuisance, not a danger. A gas smell means you leave and call SoCalGas from outside. A leaking water heater means shutting off its water and power. Otherwise, arrange a visit within a day or two.