Hot water should be available for washing dishes, doing laundry, and taking showers with a gas water heater. When the water suddenly turns cold or the gas water heater stops producing hot water the problem can be frustrating. Several factors can prevent a gas water heater from heating, including a faulty thermostat, burner, gas supply issue, or sediment buildup.

You can determine when professional gas water heater repair is necessary by understanding the causes.

Check the pilot light

It is important to check the pilot light on a traditional gas water heater. When the water needs to be heated, the pilot flame ignites the burner. The main burner may not ignite if the pilot light goes out, leaving you without hot water.

When a pilot light goes out, it can be caused by a gas supply interruption, a dirty pilot assembly, a faulty thermocouple, or a gas control issue. Some gas water heaters have manufacturer instructions for relighting the pilot so always follow the instructions printed on the unit.

If the pilot light repeatedly goes out after being relit the problem may need diagnosis instead of repeated attempts to restart it.

Look for a burner problem

The main burner underneath the tank heats the water. Gas water heaters that have a working pilot light but do not ignite the main burner may have a problem with the burner assembly or gas control valve.

Dirt, dust, corrosion or other buildup can affect burner performance. A malfunctioning gas control valve can also stop the amount of gas from reaching the burner.

A qualified plumber can inspect the burner and related components to see whether cleaning, adjustment or replacement is necessary.

Check the gas supply

It is impossible to operate a gas water heater without a gas supply. It may be a gas supply issue if other gas appliances in the home are not working as well.

Never attempt to repair a gas line yourself. If you smell gas around the gas water heater or inside your home to avoid flames and electrical switches, leave the area and contact the appropriate emergency gas service or a qualified professional.

If there is no gas odor but the gas water heater is not receiving gas properly a professional can safely investigate the supply and control components.

There may be a problem with the thermocouple

Many traditional gas water heaters use a thermocouple as a safety device. The thermocouple detects the pilot flame. Helps prevent the gas valve from supplying gas when the flame is not present.

If the thermocouple becomes dirty, damaged, misaligned or defective it may incorrectly detect that the pilot flame is out. As a result, the pilot light may go out and the burner will not work.

A plumber can test the component. Determine whether it needs cleaning, adjustment or replacement.

Sediment buildup can reduce heating performance

Over time minerals naturally found in water can settle at the bottom of a tank-style gas water heater. Sediment can create a layer between the burner and the water that reduces the efficiency of heating

Heavy sediment buildup can also cause rumbling or crackling sounds while the gas water heater is operating. In cases it can reduce hot water production and cause other performance problems.

Regular maintenance can help reduce sediment-related problems although the appropriate maintenance procedure depends on the type, age and condition of the gas water heater.

Check the temperature setting

A gas water heater may appear to have a heating problem when the temperature setting has simply been changed. Check the manufacturer’s recommended setting. Make sure the control has not been accidentally adjusted.

Avoid setting the temperature high because excessively hot water can increase the risk of scalding.

The water heater may be too small for your household

If your gas water heater produces water normally but runs out unusually quickly the problem may not be a mechanical failure. It may simply be that your household uses more hot water than the gas water heater tank can supply.

Multiple showers, laundry, dishwashing and other hot-water demands can quickly use the supply. If this happens frequently a professional can evaluate your household’s hot-water demand. Determine whether the existing gas water heater is appropriately sized.

When should you call a plumber?

If your gas water heater is not heating, professional inspection is an idea when basic checks do not resolve the issue. Problems involving gas valves, burners, thermocouples, combustion components or gas connections should be handled by a professional.

You should also seek help if the pilot light repeatedly goes out, the burner will not stay lit, the tank is leaking, you notice unusual combustion behavior or the gas water heater is producing unusual noises.

A leaking tank is particularly important because a tank that has developed a leak generally cannot be repaired by simply replacing a small external component.

Keep your gas water heater maintained

Regular gas water heater maintenance can help identify developing problems before they become failures. A professional inspection can include checking the burner assembly, safety components, connections, temperature controls and overall condition of the gas water heater.

Keeping the area around the gas water heater clear and following the manufacturers maintenance recommendations can also support operation.

If your gas water heater is not heating don’t assume that the entire unit needs to be replaced. The actual cause could be a simple component or maintenance issue. Having the system properly diagnosed can help you understand the repair options and avoid replacement.

For gas water heater troubleshooting, repair and plumbing assistance Gordon Family Plumbing can help identify the cause of your hot water problem and recommend the appropriate solution for your home.