Water Heater Not Working? Here Are the 10 Most Common Problems (And How to Fix Them)

Before you call a service technician in to look at your faulty water heater, it’s worth taking a look at it yourself. If it’s one of the most common water heater issues, you may be able to get your water heater working again. 

The 10 Most Common Water Heater Issues

If you understand the most common water heater issues, you’re more likely to be capable of fixing them on your own. Plus, once you know the most common problems, you’ll also be able to spot the most common warning signs for water heater issues. 

Here’s what you should know, especially if you’d like to get the most value out of your water heater:

1. Tripped Breaker (Electric Water Heater)

If a breaker tripped, your electric water heater isn’t getting any power—and that’s a major issue. Thankfully, it’s one that can be quickly resolved. 

Here’s how to check when your electric water heater isn’t working:

1. Check the circuit breaker. A tripped circuit can cause your electric water heater to stop heating water. Follow our guide on how to reset your circuit breaker if you need help. If you continue having issues, check out our list of reasons your circuit breaker keeps tripping. 

2. Test the voltage. If the circuit breaker isn’t tripped, turn off the power to the system’s unit at the circuit breaker and use a non-contact voltage tester to test all of the wires in the water heater.
3. Check for a failed heating element. If your electric water heater isn’t producing hot water and it hasn’t tripped a breaker, you’re likely facing one of two problems:

• • It tripped a limit switch.
  • You have a failed heating element.

Remove the upper heating element’s access panel and then take off the plastic safety guard and insulation. Be careful; you don’t want to touch any electrical terminals or wires. If you open up the access panel and find fiberglass insulation, wear safety goggles and gloves to handle it.

The high-temperature cut-off reset button is the red button just above the upper thermostat. Press it, and then replace the insulation, safety guard, and access panel. Flip the breaker back on. If your electric water heater still isn’t getting hot, you’ll probably have to get one or more heating elements replaced.

2. Pilot Light Went Out (Gas Water Heaters)

When a gas water heater isn’t heating water, chances are that the pilot light has gone out. That tiny flame serves as the ignition source for a larger burner, so it’s essential for consistent operation and performance.

To see if it has, remove the access panel at the bottom of your gas water heater. This should reveal a viewing window through which you can see the water heater pilot light. You may have to turn off the light and lay down on the floor to peer through the viewing window. 

If you do not see the pilot light, you’ll need to turn it back on. Newer water heaters have an electric igniter switch to make it easy. There should be instructions printed on the side of your water heater to help you relight the pilot light, but in general, it’s done like this:

1. Turn the gas knob to “pilot,” then press and hold it down. If your water heater has a second gas knob just for the pilot light, press and hold that one instead.
2. While holding the gas button down, press the igniter button. This should produce a spark that will ignite the gas coming out of the pilot orifice. You should be watching through the viewing window while you complete this process, so you can see when the pilot light comes on. Darkening the room will help you see it more easily.
3. Keep holding the gas knob down for a full minute so that the pilot light can heat the thermocouple, allowing it to produce the electricity it needs to operate the gas valve. 
4. After one minute, release the gas knob or pilot switch. Verify via the viewing window that the pilot light is still lit. 
5. If the pilot light goes out, repeat the process. If it stays lit, you can turn the gas knob to your desired temperature. 

If your water heater pilot light keeps going out, there may be debris in the orifice. To clean it, turn the gas knob to “off,” remove the bracket holding the pilot orifice and thermocouple tubes in position, and clean it with a stiff wire brush or poke a thin wire into it. Then replace the bracket and try lighting the pilot light again.

If the pilot light won’t light at all, make sure that the gas valve on the main gas supply line into your home is open. If you’ve recently had the water heater installed, there may be air in the gas line; to flush it out, hold down the pilot knob until you can smell the rotten egg smell of natural gas. Release the knob and wait at least ten minutes for the gas to dissipate before you try lighting the pilot light again.

3. Low Gas Pressure (Gas Water Heaters)

Low gas pressure can lead to insufficient heating or no hot water at all—which can leave you and the rest of your family frustrated.

Here’s how to troubleshoot and address low gas pressure issues in gas water heaters:

1. Check the gas supply. Ensure that the main gas valve supplying gas to your home is fully open. If it’s partially closed, this can restrict gas flow and cause low pressure. Verify that the gas meter is working correctly. If you suspect a problem, contact your gas supplier to check for issues with the gas line or meter.
2. Inspect the gas line. Look for any visible signs of damage or kinks in the gas line leading to the water heater. Damaged or bent gas lines can restrict gas flow. If you detect any gas leaks (a rotten egg smell), turn off the gas supply immediately and contact a professional plumber or your gas company for assistance.
3. Check the pressure regulator. The gas water heater has a pressure regulator that controls the gas flow. If this regulator is faulty, it can cause low gas pressure. Locate the pressure regulator near the gas valve and check for any signs of damage or wear. If you suspect a problem, it may need to be replaced by a professional.
4. Clean the burner and orifice. Debris and dirt can clog the burner or the orifice, leading to low gas flow. Turn off the gas supply and clean these components using a stiff wire brush. Remove the burner assembly and use compressed air or a thin wire to clean the orifice. Reassemble and test the water heater.
5. Test the thermocouple. A faulty thermocouple can prevent the gas valve from opening fully, reducing gas pressure. If the pilot light goes out frequently, this may be the issue.

Inspect the thermocouple and replace it if necessary.

4. Low Water Pressure (All Water Heaters)

Low water pressure can affect both gas and electric water heaters, leading to reduced water flow everywhere else in the home—the washing machine, the shower, the bathtub, and your sinks.

Here’s how to troubleshoot this issue:

1. Check the main water supply. Ensure that the main water valve supplying water to your home is fully open. If the main valve is open and you still have low pressure, check with your water supplier to see if there are any issues or maintenance work affecting the supply.
2. Inspect the shut-off valve. Check the shut-off valve near the water heater to ensure it’s fully open. Sometimes, these valves can be accidentally partially closed during maintenance.
3. Examine the water lines. Look for any visible signs of leaks, kinks, or blockages in the water lines leading to and from the water heater. Damaged or blocked lines can restrict water flow. If you detect a leak, turn off the water and repair the leak before turning it back on.
4. Flush the water heater. Sediment build-up inside the water heater tank can reduce water flow and pressure. To flush the tank, turn off the power or gas supply, and connect a hose to the drain valve at the bottom of the tank. Open the valve and let the water and sediment drain out. Close the valve, remove the hose, and refill the tank.
5. Check for mineral deposits. Mineral deposits can build up in the water heater and plumbing, restricting water flow. Installing a water softener can help prevent future build-up. For immediate relief, consider using a descaling solution to clean the water heater and plumbing.
6. Inspect the pressure-reducing valve. Some homes have a pressure-reducing valve (PRV) installed on the main water line. If this valve is set too low or is malfunctioning, it can cause low water pressure. Adjust or replace the PRV if necessary.

5. Discolored or Rusty Water (All Water Heaters)

Discolored or rusty water can indicate corrosion or other issues inside the water heater. In most cases, the solution is relatively simple, though some (like installing a water softener) can be more expensive.

Here’s how to troubleshoot this problem:

1. Identify the source. Determine if the discoloration is only in the hot water. If both hot and cold water are discolored, the issue may be with your home’s plumbing rather than the water heater. If only the hot water is discolored, the problem is likely within the water heater.
2. Flush the heater. Sediment and rust can accumulate in the water heater tank, causing discoloration. To flush the tank, turn off the power (electric) or gas supply (gas), and connect a hose to the drain valve at the bottom of the tank. Open the valve and let the water and sediment drain out. Close the valve, remove the hose, and refill the tank.
3. Inspect the anode rod. The anode rod helps prevent rust inside the water heater tank. If it is corroded, it may need to be replaced. Turn off the power or gas supply, drain some water from the tank, and remove the anode rod. Replace it if it’s heavily corroded.
4. Check for corrosion. Inspect the inside of the tank for signs of corrosion. If the tank itself is corroding, it may need to be replaced. Corrosion is a sign that the tank is nearing the end of its lifespan.
5. Install a water softener. Hard water can contribute to sediment and rust build-up in the water heater. Installing a water softener can help reduce mineral deposits and extend the life of the water heater.

6. Strange Noises (All Water Heaters)

Strange noises coming from your water heater can indicate a variety of issues—and they can also be a worrisome distraction. Fortunately, most noises aren’t a serious concern, and the causes can be quickly rectified. 

Here’s how to troubleshoot these sounds:

1. Popping or rumbling. This is usually caused by sediment build-up at the bottom of the tank can trap water underneath. When the water heats up, it causes the sediment to shift and create popping or rumbling noises.

The Fix: Flush the water heater to remove sediment. Connect a hose to the drain valve, open the valve, and let the water and sediment drain out. Close the valve, remove the hose, and refill the tank.

2. Hissing or sizzling. These noises can occur if there is a leak in the tank or if the heating element is covered with sediment or scale.

The Fix: Check for leaks around the tank. If you find a leak, turn off the water supply and power to the heater and contact a professional to repair or replace the tank. If the heating element is scaled, clean or replace it.

3. Knocking or banging. Knocking or banging sounds can be caused by water hammer, which occurs when water flow is suddenly stopped and the pipes bang against each other or the wall.

The Fix: Install a water hammer arrestor to absorb the shock and stop the banging. This device can be installed on the water supply lines to the heater.

4. Ticking or tapping. Thermal expansion can cause ticking or tapping noises as the pipes expand and contract with changes in temperature.

The Fix: Install expansion tanks or loops to accommodate the thermal expansion and reduce the noise.

5. Crackling. This sound can occur if the water heater’s burner or heating elements are covered with sediment.

The Fix: Clean the burner or heating elements to remove the sediment build-up. Flushing the tank can also help prevent this issue.

7. Water Heater is Leaking (All Water Heaters)

A leaking water heater can cause significant damage to your home if not addressed promptly. Identifying and fixing the source of the leak is crucial to prevent further issues.

Here’s how to troubleshoot when your hot water heater’s leaking:

1. Check the inlet and outlet connections. Inspect the connections at the top of the leaking water heater. If you notice any water around these connections, tighten them with a wrench. If the connections are corroded, they may need to be replaced.
2. Examine the pressure relief valve. The pressure relief valve releases excess pressure to prevent the tank from exploding. If the valve is leaking, it could be due to high pressure or temperature. Test the valve by lifting the lever and letting it snap back. If water continues to leak, replace the valve.
3. Inspect the drain valve. The drain valve at the bottom of the tank is used to empty the tank for maintenance. If it’s leaking, ensure it’s tightly closed. If the leak persists, you may need to replace the valve.
4. Check the tank for cracks. Inspect the tank for any visible cracks or holes. If the tank itself is leaking, it’s usually a sign that it has reached the end of its lifespan and needs to be replaced.
5. Look for leaks at the base. Water at the base of the water heater can indicate a leak from the internal tank. If the internal tank is leaking, the entire water heater will need to be replaced.
6. Examine the anode rod. The anode rod prevents corrosion inside the tank. If it’s corroded, it may cause leaks. Turn off the power or gas supply, drain some water from the tank, and remove the anode rod. Replace it if it’s heavily corroded.

8. Water Heater Smells (All Water Heaters)

Unpleasant odors from your water heater can make using hot water an unpleasant experience. The smell is often caused by bacteria or other contaminants inside the tank.

Here’s how to troubleshoot and fix those hot water heater smells:

1. Identify the type of smell. A rotten egg smell typically indicates bacteria in the tank, while a metallic smell can suggest corroded components. 
2. Flush the tank. Bacteria and sediment build-up can cause odors. To flush the tank, turn off the power or gas supply, and connect a hose to the drain valve at the bottom of the tank. Open the valve and let the water and sediment drain out. Close the valve, remove the hose, and refill the tank.
3. Treat the tank with hydrogen peroxide. For bacterial contamination, fill the tank with a mixture of hydrogen peroxide and water. Use about one to two pints of hydrogen peroxide for a 40-gallon tank. Allow the mixture to sit for a few hours before flushing the tank again.
4. Replace the anode rod. If the smell persists, the anode rod may be contributing to the problem. Some anode rods are more prone to causing odors. Consider replacing the existing anode rod with a different type, such as a powered anode rod, which can help reduce odors.
5. Install a water softener. Hard water can contribute to bacterial growth and odors. Installing a water softener can help reduce mineral deposits and bacterial growth.
6. Maintain proper temperature. Keeping the water heater at a temperature of at least 140°F can help kill bacteria and prevent odors. However, be cautious as higher temperatures can increase the risk of scalding. Adjust the temperature according to your household needs while ensuring it’s high enough to prevent bacterial growth.

9. Water Is Getting Too Hot (All Water Heaters)

Water that is too hot can be a safety hazard and may indicate a problem with your water heater’s thermostat or temperature settings. Addressing this issue promptly can prevent scalding and reduce energy consumption.

Here’s how to troubleshoot when your water heater’s too hot:

1. Check the thermostat. Locate the thermostat and ensure it is set to a safe temperature, typically between 120°F and 140°F. If it is set too high, adjust it to a lower temperature.
2. Test the thermostat. If the water remains too hot despite lowering the thermostat setting, the thermostat may be malfunctioning. Use a multimeter to check for continuity. If the thermostat is faulty, it will need to be replaced.
3. Inspect the heating elements. In electric water heaters, a faulty heating element can cause the water to overheat. Turn off the power to the water heater, remove the access panel, and test the heating elements with a multimeter. Replace any faulty elements.
4. Examine the pressure relief valve. If the pressure relief valve is malfunctioning, it can cause the water heater to overheat. Test the valve by lifting the lever and letting it snap back. If it doesn’t function correctly, replace the valve.
5. Check for sediment build-up. Sediment build-up at the bottom of the tank can cause the water heater to overheat. Flush the tank to remove sediment and prevent overheating.
6. Reset the high-temperature cutoff switch. The high-temperature cutoff switch is designed to shut off the water heater if the water gets too hot. If it has tripped, reset it by pressing the red button located above the upper thermostat. If it continues to trip, there may be an underlying issue that needs to be addressed by a professional.

10. Water Isn't Getting Hot Enough (All Water Heaters)

When your water heater isn’t producing enough hot water, it can be frustrating and inconvenient. This issue can be caused by several factors, ranging from simple thermostat adjustments to more complex mechanical problems.

Here’s how to troubleshoot when your hot water heater’s not getting hot:

1. Check the thermostat. Ensure the thermostat is set to an appropriate temperature, typically between 120°F and 140°F. If it is set too low, increase the temperature setting.
2. Test the thermostat. Use a multimeter to test for continuity. Replace the thermostat if it is not functioning correctly.
3. Inspect the heating elements. In electric water heaters, a malfunctioning heating element can result in insufficient hot water. Turn off the power to the water heater, remove the access panel, and test the heating elements with a multimeter. Replace any defective elements.
4. Check for sediment build-up. Sediment build-up can insulate the water from the heating elements, reducing the efficiency of the water heater. Flush the tank to remove sediment and improve heating performance.
5. Examine the dip tube. The dip tube directs cold water to the bottom of the tank, where it can be heated. If the dip tube is broken or damaged, cold water may mix with hot water at the top of the tank, resulting in lukewarm water. Replace the dip tube if it is damaged.
6. Inspect the gas supply. For gas water heaters, insufficient gas supply can cause the water heater to produce less hot water. Ensure the gas valve is fully open and check for any issues with the gas line or pressure regulator. If necessary, contact your gas supplier for assistance.
7. Check the pilot light. If the pilot light on a gas water heater is out, the burner will not ignite to heat the water. Follow the manufacturer’s instructions to relight the pilot light. If it goes out frequently, there may be an issue with the thermocouple or gas supply.
8. Test the thermocouple. The thermocouple ensures the gas valve opens when the pilot light is lit. If the thermocouple is faulty, the burner may not ignite, leading to insufficient hot water. Replace the thermocouple if it is not working correctly.

Protect Your Water Heater With A Home Warranty

Cover your water heater with an American Home Shield® home warranty. Every one of our plans covers electric and gas water heaters!

Check out our coverage to learn more. 

And if you’re already an AHS member,you can request service for covered repairs.  for support. 

AHS assumes no responsibility, and specifically disclaims all liability, for your use of any and all information contained herein.