Having been a homeowner for over a decade, I can attest to the reliability of modern water heaters. Whether powered by gas or electricity, these appliances are indispensable, providing hot water for everything from showers to cleaning.
However, as reliable as they are, when they fail, it can cause significant disruption to daily life.
Most water heaters have two heating elements, one near the top of the tank and one further down. The electricity heats the element’s metal loops, which heats the surrounding water. Depending on the size of the water heater and recovery time, these heating elements have different wattages from one water heater to another.
The water heater has been able to work perfectly for years. However, over time, these water heaters will experience some common problems.
Why Does My Water Heater Keep Turning Off?
Few things are worse than getting ready for a nice shower or bath only to discover that no hot water is available. But this is the situation you can find yourself in if your gas water heater shuts off without warning after 5 minutes!
The pilot light cannot ignite, or issues with the gas supply are the major causes of a gas water heater turning off on its own.
Here, we examine how you may resolve this situation and strengthen your hot water supply.
- Thermocouples in Dirty Conditions
In my years of experience as a plumbing professional, I’ve often seen thermocouples fail due to dirt accumulation. A customer once had a water heater that repeatedly turned off mid-shower, which frustrated them. Cleaning the thermocouple resolved the issue instantly, highlighting how something so simple can cause significant inconvenience.
Read also: Water Heater Not Heating After Replacing Elements and Thermostat
After around 30 seconds, the pilot light’s heat triggers a thermocouple, a cheap electrical switch that ensures the gas supply to the pilot light stays open and your water heater keeps working.
The thermocouple can become soiled, twisted, or broken if you repeatedly switch your gas water heater off. Usually, you may see it right next to the pilot light.
Check the thermocouple to see if it is filthy or damaged. If it is dirty, turn off the gas to let it cool. Then, you can clean it by lightly sanding it with fine sandpaper.
- The Heating Element on Fire
If the hot water from your faucet turns warm rather than hot, it’s often a sign of a failing heating element. From my personal experience, this is particularly true if the element has worn out due to years of use. In one case, a homeowner’s water heater shut off repeatedly because the heating element was corroded—a situation that could have been avoided with regular maintenance.
However, a faulty bottom heating element shows slightly different symptoms; the water from the faucet starts to get quite hot but then quickly cools down.
- Pilot Tube is Dirty
In the pilot light tube, dirt or soot buildup may result in a weak flame or even the failure to light the pilot light. If you observe a faint, flickering yellow light emerging from your pilot burner instead of an intense, blue flame that rises no higher than a half-inch, you most likely have a filthy pilot burner.
When the pilot tube has cooled, you may carefully clean it with a needle to eliminate clogs, but if problems continue, contact a licensed plumber.
- An Error in the Gas Valve
My water heater keeps turning off; what did I do wrong? Your gas water heater will turn off if the gas valve or its inner components get broken, cutting off the gas supply to the pilot light or burners.
If you’ve ruled out problems with your pilot light or thermocouple, the gas valve in your water heater is most likely the issue. Your plumber is the best person to repair or replace the gas valve.
- Unclean or Blocked Air Inlet
Modern gas water heaters often have air inlet screens that can become blocked over time. In my practice, neglected screens are a common cause of water heater shutdowns. A simple cleaning can prevent these issues, so I always advise my clients to include air inlet checks in their annual maintenance routines.
If you ever smell natural gas from your water heater, leave your house immediately, shut off the gas, and contact your gas provider for emergency help.
Common Issues and Solutions Table
| Issue | Cause | Solution | Personal Insight |
|---|---|---|---|
| Thermocouple Failure | Dirt, clogging, or breakage | Clean or replace thermocouple | “A dirty thermocouple once caused a client’s water heater to shut off every hour. Cleaning it restored normal function.” |
| Gas Valve Problems | Faulty gas valve or gas leak | Replace the valve, contact professionals | “Gas leaks are no joke—always call in a professional if you suspect one. I’ve seen the dangers firsthand.” |
| Clogged Air Inlet | Dust, lint, or debris blocking air inlet | Clean the air inlet screens | “I recommend regular inspections—one client’s screen was so clogged that the heater couldn’t stay on.” |
| Heating Element Damage (Electric) | Burnout, corrosion, or electrical issues | Replace heating element | “A burnt-out element can make your hot water turn lukewarm, as I found with one customer’s malfunctioning unit.” |
What is a Pilot Light Heater?
A smaller gas flame, often made of natural or liquefied petroleum gas, is used as a pilot light to ignite a larger gas burner. It initially kept a pilot light on all the time. However, this wastes gas. Although electrical ignition is becoming more prevalent, gas pilot lights are still utilized when a high-energy ignition source is required, such as when lighting a big burner.
Why does my water heater keep turning off? Typical uses include home water heaters, central heating, fireplaces, flamethrowers, and hot air balloons.
Domestic systems use an electrical ignition, although most commercial kitchens still use pilot lights for burners, ovens, and grills. On newer remote-controlled fires, this is more usually referred to as standby.
