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Gas Water Heater Troubleshooting

Gas water heaters are sought out for their convenience and affordability. However, you can have many issues with a poorly maintained tank. Understanding how to make repairs at home will save you money, but you need to make sure you take safety precautions, especially with gas water heaters.

Following safety first

There are several repairs that you can make on your gas water heater without the help of a professional repairman. However, gas is explosive and can cause extensive damage when handled incorrectly. Always turn the gas off to your water heater before making repairs. If you smell natural gas, turn the pilot light off and shut the gas off at the main valve. Never use an electrical device near a natural gas leak. This includes light switches. Leave your home and call the local gas company or a plumbing professional who works with natural gas appliances.

Troubleshooting common issues

Several issues can arise when using a gas water heater. A few of these issues can be fixed for less than $20 and take very little time to repair. However, some issues require a professional. To keep household costs down, you can learn a few do-it-yourself (DIY) repairs to avoid costly service calls.

Typical issues with gas water heaters include

  • No hot water
  • Not enough hot water
  • Rust colored water
  • Rattling or low rumbling sounds coming from the tank

No Hot Water

If you notice you have no hot water, the culprit is usually the pilot light. Check to see if it has gone out. Your water heater should have instructions on the side of the tank showing you how to relight the pilot light. If the pilot does not light or remain lit, you probably have a faulty thermocouple. You should be able to replace thermocouple in an about hour, and the cost is typically under $20.

Replacing the thermocouple

Before you go any further, turn both the gas valve leading to the heater and the gas valve in the heater to the off position. Next, remove the three nuts that support the thermocouple and the two gas tubes that go to the valve. You can remove the burner for cleaning and check for leaks or faulty ports. If you notice debris or dust, you can wipe or vacuum out the area.

Once you remove the old thermocouple, take it with you to a hardware store to ensure you get the right replacement part. Using the instructions on the back of the new thermocouple package to replace it. Consulting your owner’s manual may also be helpful.

Make sure to return the burner assembly before installing the thermocouple. Once this is complete, follow the instructions on your water heater to light the pilot light. If you are concerned about gas leaks, apply soapy water to the lines and joints and watch for bubbles. Bubbles mean there is gas escaping. Checking for leaks should be done while the main burner is firing.

Not Enough Hot Water

Several issues could cause a lack of hot water. Your water heating demands may be too much for the water tank to handle. A faulty dip tube, crossed cold and hot water connections, and gas supply or control problems can be the root of the problem as well.

Tank is too small

If your family uses more water than the tank can replenish in a short time, you need a bigger tank. Install a larger tank to ensure proper water supply.

Faulty dip tube

Check the dip tube by undoing the cold water inlet and nipple. Pull the dip tube and replace it if necessary.

Crossed water lines

You can check for a crossed water source by shutting the water supply to your water heater off. Turn on the hot water on a faucet. If you have hot water, your connections are crossed. Check all of your water connections for a hot water line connected to a cold water line. The crossed line can be on a shower valve, dishwasher, washing machine, or faucet.

Gas supply issues

Look at the water heater burner for an accurate flame. If you use natural gas, the flames should be blue with yellow tips. Propane water heaters will have blue-green flames with yellow tips. If the flame is weak, you may need more fuel. Check other gas appliances in the home. If they do not work, contact your gas supplier and order more gas.

Rust Colored Water

There are several causes of rust colored water, including clay, sand, and mud sediment reaching the water heater through water main breaks or well systems. Corrosion inside a glass-lined tank or faulty anode rods can also turn your water brown.

Flushing the water lines

Flushing chlorine bleach through all the lines in your home will fix most of these issues. First, turn the gas supply from the water tank off. The next step is to drain the tank. Remove the anode rod and close the drain valve on the tank. Add one gallon of bleach for every 25 gallons of water held in the tank. Replace the anode and fill the tank with water.

Open each water line coming from the water tank and turn it off when you smell bleach. Let the bleach stay in the lines for an hour. All lines throughout the house should be flushed, including the washing machine and dishwasher. After an hour has passed, drain the tank again and refill it. You should notice an improvement after the line is cleared. To avoid bleaching your clothing or skin irritation, run water through each line again until the bleach is gone.

Identifying and repairing water tank noises

Not all sounds coming from your water heater mean a repair is needed. However, most of the time these sounds indicate that the tank needs to be flushed or replaced. Sediment collects over time and can cause your tank to rattle, rumble, and scream. If sediment is the cause, you will have to de-lime your tank or have a professional repairman do it for you.

Flushing your tank

Follow these seven steps to flush lime from your tank.

  1. Shut off the gas during the flushing procedure.
  2. Open a hot water faucet in the kitchen or bathroom. This keeps air out of the lines as the tank drains and refills.
  3. Connect a hose to the drain on the bottom of the tank, then take the other end of the hose outdoors so it can drain. You can then open the drain valve so the hot water in the tank can empty. The water will be very hot, so be careful.
  4. When all the hot water has emptied, turn on the cold water valve going to the tank. Continue to flush the tank until you no longer see sediment coming out of the drain hose outside. You can now turn off the cold water.
  5. Remove the drain valve and scrape out any remaining debris with a coat hanger. You can also remove the scraped sediment by applying a ½-inch tube to your wet dry vacuum with duct tape. The smaller tube will allow you to get into the drain valve easier.
  6. Apply plumbing tape to the drain valve threads and screw it back into the tank. Flush the tank once more, then close the valve and fill the tank with cold water.
  7. Check the hot water faucet you left in the on position during the filling process. When water appears out of the faucet, you can turn it off.

You should make sure the tank is full before turning on the heating element. If you turn on the heating element too soon, it can cause the heater element to burn out. It can also the tank’s lining.

Taking repairs into your own hands can give you a sense of accomplishment, especially when you can save some money by avoiding professional service calls. You can make several small adjustments and repairs on a gas water heater without blowing your budget. However, you need to ensure your safety by following proper repair procedures. Some repairs, such as damaged gas lines, will require the assistance of a professional repairman. 

Gas water heaters are essential in a household setup as they are used for several purposes such as cooking, cleaning, bathing, space heating and so on. These gas water heaters require combustion of a fossil fuel in order to heat the water. The heat level of the water can also be controlled with the use and help of thermostats. Within a domestic setting, these appliances are simple to operate generally requiring a switch to engage and disengage. Listed below are a few commonly asked questions that have been answered by the Experts on gas water heater problems.

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