The average water heater lasts anywhere from 6 to 13 years. These appliances require upkeep. Heating water accounts for about 20% of your household energy use, so it’s important that your water heater runs as efficiently as possible.
If you hop in the shower and the water doesn’t warm up at all, your water heater may not be turning on. If this is the case, there could be a simple fix. Some problems require calling a professional, but understanding some of the basic water heater issues can help you determine if you can do it yourself. You just have to investigate the power source for your type of water heater to find the issue.
The type of water heater will determine how you go about repairs.
Gas Water Heater Repairs
Gas water heaters use gas-fired burners at the bottom of the tank to heat the water inside.
Relight the Pilot Light
If you have a gas water heater that isn’t working, your pilot light might be the problem. Most pilot lights are located at the bottom of the water heater, underneath the tank. It could be behind an access panel or glass screen. Check the manual for your water heater or follow these instructions to relight the pilot light.
If you light the pilot but it goes out immediately, make sure you hold in the gas control knob for 20 to 30 seconds. If the pilot light still goes out after this, you may need to repair or replace the thermocouple.
Identify the Thermocouple or Flame Sensor
The thermocouple is a copper-colored wire with two connective ends. It keeps the pilot light aflame by producing an appropriate voltage in between the two junctions based on the temperature of the water. Before attempting to fix this part, you must find out if your water heater has a traditional thermocouple or a flame sensor.
Some newer gas water heaters use a flame sensor. These electronic-ignition systems work similarly to thermocouples, but they sense that the burners are lit by detecting gas. Both systems trigger ignitions that light up the pilot light and burners when the water becomes cooler than the heater setting.
You can find the flame sensor or thermocouple attached to the inside of the burner assembly, directly in front of the pilot light. Flame sensors are typically the more reliable of the two, but dirt and debris can prevent them from lighting the pilot light or igniting the burner.
Clean the Thermocouple
Before removing the burner assembly to check for debris, make sure you also shut off the gas valve on the water heater and the gas line next to the water heater. Only work on your gas water heater if you feel safe to do so, because explosions and accidents can happen if handled improperly. If you feel more comfortable calling in a professional, that is the best route to take for your safety.
If you choose to go forward with cleaning your thermocouple or flame sensor, you can clear out any dirt and dust you notice using a vacuum with a slender attachment. It should start working properly again if it was only minorly clogged. If the pilot light still doesn’t ignite after vacuuming the area, the flame sensor or thermocouple may be bad. Older parts may exhibit greater signs of wear and tear, such as metal scaling, but sometimes they simply stop working.
Adjust the Thermocouple Wire
There are a few other explanations for a malfunctioning pilot light that you should consider before replacing the thermocouple, however. The thermocouple wire could simply be too far from the pilot light. Test the thermocouple and adjust the wire as necessary.
Clear the Pilot Hole
If the pilot light won’t light at all, there may be an obstruction in the pilot tube. This may also be the case if the flame is weak with an orange tinge. In this instance, it’s likely too small for the thermocouple to detect. You can clear out debris from the pilot tube to try and increase the flame size.
Turn off the gas, first and foremost. You can find the pilot hole at the entrance of the pilot supply line. It looks like a small, brass tube. When you find the tube, twist it to the left to unscrew. It is very narrow, so the best way to clear any debris is to rub a cotton swab soaked with rubbing alcohol along the edges. You may also use compressed air to dislodge any stubborn debris. Once clear and reassembled, turn on the gas and try to relight the pilot light.
Replace the Thermocouple
If you’ve tested the above explanations and still have a weak or no pilot light, consider replacing the thermocouple or flame sensor. This is inexpensive and easy, requiring a replacement part and wrench to complete. Home-improvement and online stores will typically have replacement thermocouples, but do contact a professional if you’re unsure what to purchase or feel unsafe following the instructions for replacement.
If you choose to replace the thermocouple yourself, make sure to shut off the gas first. There are typically three nuts that hold the thermocouple. Loosen them to remove the entire burner assembly. It should slide out easily from the burner chamber. Then, you can remove the thermocouple and replace it with the new one, reassembling the burner after you are done and testing the pilot light.
Here’s a helpful video from Pros DIY that walks you through the thermocouple replacement process.
Electric Water Heater Repairs
Electric water heaters have high-voltage rods that heat up the water inside the tank. This complicates things a bit when looking for the root of your water heater issues.
Assess the Breaker, Fuse, and Safety Switch
If you have an electric water heater that isn’t working, you’ll want to turn off the power source before working on repairs. In some cases, a simple flip of the breaker or replacement of a blown fuse can fix the problem. Some electric water heaters even have a safety switch that trips a reset if it detects issues. Resetting this switch near the thermostat may solve the problem, but if your water heater continues to trip the reset button, look for additional issues.
Test the Voltage
The next step is to test the voltage with a multimeter. A multimeter is a test tool designed to measure electrical values. This will give you an idea of where the electrical shortage is coming from when your water heater isn’t turning on.
Electric water heaters have one or two elements that heat the water. A multimeter can test the voltage of these elements to see if they are working properly.
First, turn off the breaker to the water heater. You will need to remove the top and bottom panels and insulation to address the element face. Then, test the water heater elements with the multimeter by making contact with screws and the metal base of the element. If the needle on the multimeter moves, the element needs to be replaced.
Most homeowners can make this repair themselves, but always contact a professional if you don’t feel comfortable handling water and electrical elements. These elements are often called immersion elements because they heat the water while immersed in the tank.
Replace Electric Water Heater Elements
Replacing water heater elements requires you to know which type of element is inside your appliance. Newer heaters will likely have screw-in elements, and older heaters typically have bolt-in elements. You can look on the water heater for a physical stamp describing the water heater elements, or you can search the make and model of your water heater online.
There are also upper and lower heating elements. Lower elements are more commonly replaced due to the accumulation of sediment in the tank bottom. You can determine which one has gone bad by testing the water heater elements with a multimeter. Once you figure out the exact type of water heater element that needs replacing, find a replacement with the same voltage.
You can opt for lower wattage when replacing the element to extend the life of your water heater and save energy. If you do this, the appliance will put out less heat than you may have been used to before the issues with heating occurred. Also, consider the age of your water heater and the type of water in your area when selecting a replacement element. Reach out to a professional if you need help determining the right replacement part.
If you have any reservations about working with electricity and water, contact a plumbing professional to do this work. If you feel safe doing this work, flip off the circuit breaker and test the voltage with the multimeter to ensure there is absolutely no power being pumped to your water heater before you start. Follow further instructions for replacing the water heater element(s), with or without draining the tank.
This handy video from Jim Viebrock shows you how to replace the heating element in your water heater.
Saving Water and Energy
Keeping your appliances working properly helps them work efficiently and helps you avoid wasting water or energy. It can also extend their life. By repairing your water heater in a timely manner, you’re contributing to the sustainability of your home.
About the Author
Sam Bowman writes about people, the environment, tech, and how they merge. He enjoys getting to utilize the internet for community without actually having to leave his house. In his spare time, he likes running, reading, and combining the two in a run to his local bookstore.