Water Heater Shuts Off After 5 Minutes? – Reasons & Fix

It can be extremely annoying when your water heater shuts off after 5 minutes after turning it on. Don’t worry, you’re not alone.

So, in this guide, I’ll be going over the reasons why this happens, as well as outlining the comprehensive method of fixing it completely.

Your water heater turns or shuts off every 5 minutes due to problems with the gas valve or gas supply, the thermopile is dirty or faulty, the air inlet is clogged, or the pilot light burner is dusty.

To fix it, inspect the gas valve, clean the air inlet and the pilot light burner, and then check if the thermopile needs replacement.

Reasons Why Gas Water Heater Shuts Off After a Few Minutes

Gas water heaters are significant equipment that can supply your home with hot water. However, instances, where they turn off without any warning, are inevitable.

What could these reasons be?

Here are a few of the most common culprits why your gas water heaters turn off minutes after you turn them on.

Culprit #1: Gas Valve or Gas Supply Problems

The first and probably the most unnoticed factor is the gas supply. Without gas, your hot water heater wouldn’t function.

The problem can be as simple as the inlets of the gas valve being dirty and dusty because dirt, dust, and soot can build up on the gas valve.

It’s also worth double-checking if the gas valve is connected properly to the tank. Moreover, its inner elements could also be damaged, so be sure to check this out, too.

Culprit #2: Dirty or Damaged Thermopile

The next culprit is the damaged thermocouple or thermopile.

A thermopile is a metal rod that is positioned beside the burner and is the one responsible for the burning of the burner.

Similar to the gas valve, it can catch dust and dirt, and if it’s dirty, it wouldn’t be able to generate the needed electricity.

This, in turn, is why your hot water heater shuts off or doesn’t turn on.

NOTE: If the thermopile is damaged or dirty, your gas heater won’t work properly even if the pilot light is turned on.

Culprit #3: Clogged Air Inlet

Similar to any other combustion equipment, hot water heaters need air or oxygen in order for them to perform combustion, and this is what the air inlet is for.

Over time, the air inlet can be clogged and filled with dust, dirt, and soot.

If this happens, then the water heater might not be able to get enough air needed for combustion.

Culprit #4: Dusty Pilot Light Burner

When gas is activated, it climbs up to the pilot light via the main valve, activating the main gas burner, and heating the water up.

When there’s debris in the pilot light burner, the amount of gas that enters might not be enough to keep the temperature at bay.

NOTE: One sign that the issue is because of the pilot light burner is if you see a flickering yellow flame instead of blue.

Water Heater Shuts Off in 5 Minutes? Here’s a Complete Fix

The best and simplest solution to this is to first identify what’s causing the problem.

It’s a machine, and therefore, it contains components that contribute to what they do.

Follow these steps if your gas water heater shuts off after 5 minutes!

Step #1: Inspect the Gas Supply

First things first, check the gas supply. The analogy is simple, no gas = no heat. The supply of gas needs to be consistent.

1. Check if the gas valves are open.
2. Then, ensure that it’s connected to the tank properly.
3. Check if there is dust, dirt, or debris buildup on the valve.

Clean the accumulation of dirt, dust, and debris using a vacuum.

Just ensure that all other assemblies are locked in place so that no other unwanted component gets sucked into the vacuum.

Sometimes, there could be stubborn dirt or dust on the valve that a vacuum wouldn’t be able to clean. 

So, you want to wipe it off with a damp cloth. Make sure you turn the gas supply off first for safety and security!

When Should You Replace a Gas Valve?

The earliest and most common signs of gas valve damage are:

• Excessive noise coming from the hot water heater
• Water gushing out of the valve

Other than these, the gas supply should be good and just needs cleaning.

Gas valve replacement should be done by a professional. Why? Because doing so entails a long and difficult process.

Step #2: Check For Dirty Components

The next step is to check 2 of the most important components of water heaters: the pilot light burner and the air inlet.

Both of these components need to be on point for your water heater to stay on and function properly.

Clean the Pilot Light

When it comes to hot water heaters, maintenance is key. The cleaning of the pilot light burner, as well as the pilot light pipe, is crucial.

Here’s how you can clean your pilot light burner:

1. Switch the master valve off.
2. Remove the thermopile/thermocouple and pilot light assembly.
3. Then, take the pilot light from the assembly using a wrench or a pair of pliers.
4. Brush carbon, dust, or soot buildup from both components.
5. Rinse it with a clean and disinfected cloth.

Dedust the Air Inlet

Air inlets are integral components of water heaters. You can remove dust or dirt buildup using compressed air.

Point it at the air inlet and make sure to go through every corner of the inlet.

Another method, in case you don’t have compressed air, would be to remove the filter from the air inlet.

Lay it flat on the ground, and then wash it with water. Let it dry for a few minutes. Before reassembling the filter back in place, clean the inlet or shutter.

Overall, if this has been the culprit for the problem, then the solution you should be looking at is proper and regular maintenance.

You don’t necessarily have to contact your plumber for maintenance. You can do it yourself using the methods we said above. Clean the inlet at least once every month to be sure.

Step #3: Reset Your Thermocouple

After going through the gas valve, the inlet, and the pilot light burner, it’s now time to check up on your thermocouple or thermopile.

You can reset it by pressing and holding the reset button for 30 to 45 seconds. This button can be found at the center of the thermal switch.

Replacing Your Thermocouple

If your thermocouple isn’t responding well, you want to replace it. Replacing the thermocouple of your water heater is relatively easy.

1. Turn the gas valve off and leave it for at least 10 minutes.
2. Remove the assembly from the bottom of the water heater.
3. Then, detach the thermocouple by unfastening the nuts holding the assembly in place.

One of the primary signs that your thermocouple requires replacement is when the flame lights up, and then suddenly goes out after you let go of the control knob.

This should be enough to determine what’s causing the problem and at the same time, resolve the issue.

It took me a while to get to the end, but it was all worth it because I saw my water heater running straight for 3 hours without it turning off by itself.

The Bottom Line

If your water heater shuts off in 5 minutes after you just lit it up, there’s a problem.

Now, you are fully aware of what’s causing these unusual instances.

Not only that, but you also know the proper solution in getting rid of this dilemma once and for all.

Don’t panic, it’s usually something doable from your end.