How do I troubleshoot a gas water heater?

If your gas water heater is not working right, start with a few simple checks. Most problems come from the pilot light, the thermostat, the gas supply, or sediment in the tank.

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What should I check first?

Before you call for help, look at these basic items:

• Pilot light – Is it lit? If it is out, follow the lighting instructions on the heater label.
• Gas supply – Make sure the gas valve is open and your gas service is active.
• Thermostat – Check that it is set to at least 120°F.
• Power – If your heater uses an electric igniter, make sure the outlet or breaker is working.

If all of these look good and you still do not have hot water, there may be a deeper problem inside the heater.

Why does my pilot light keep going out?

A pilot light that will not stay lit is a common gas water heater problem. It can mean:

• A dirty or clogged pilot assembly
• A weak or faulty thermocouple
• Low or unstable gas flow
• Drafts blowing the flame out
• Burner or venting issues

If you have to relight the pilot more than once, it is a sign that a part may be failing. At that point, it is safer to call a licensed plumber to inspect the system.

Why don’t I have hot water?

If you have no hot water at all, the problem might be:

• The burner is not igniting
• A failed thermostat or gas control valve
• Heavy sediment buildup in the tank
• A damaged dip tube (cold water mixing with hot)
• A safety device that has tripped

Many of these parts are gas controls or safety devices. They should only be repaired or replaced by a trained, licensed plumber.

Why does my water take so long to heat?

Sometimes the water heater works, but you wait a long time for hot water. Common causes include:

• Sediment buildup – Sediment acts like a blanket and slows down heating.
• Undersized tank – The water heater may be too small for your home’s demand.
• Weak burner – A dirty or failing burner cannot heat water quickly.
• Long pipe runs – Hot water has to travel a long distance to the faucet.

Flushing the tank once a year can help prevent sediment problems and keep your heater running better.

Why does my gas water heater smell strange?

Any strange smell around a gas water heater should be taken seriously. Stop and check right away if you notice:

• A rotten egg smell (this can be a gas leak)
• A strong burning or melting smell
• Smoke, soot, or scorch marks around the heater

If you smell gas:

• Do not light the pilot or use open flames.
• Do not touch light switches.
• Leave the area and call your gas company or 911.

Then contact a licensed plumber to inspect and repair the unit. Do not operate the heater again until it has been checked and cleared as safe.

When should I call a plumber?

Call a licensed plumber if:

• The pilot light will not stay lit
• You smell gas or see signs of a leak
• You keep running out of hot water
• The water heater makes loud popping or banging noises
• You see water leaking around the base of the tank
• Your water heater is more than 10–12 years old

S.E. Tradesmen provides gas water heater repairs, replacements, and new installations. Our union-trained, master plumbers serve homeowners and businesses across Pensacola and the Gulf Coast.

FAQ

Is it safe to work on a gas water heater myself?

You can adjust the thermostat and, in many cases, safely relight the pilot if you follow the instructions on the unit. But repairs to the burner, gas valve, venting, or safety controls should be done by a licensed plumber. Gas work is not a DIY project.

How long does a gas water heater last?

Most gas water heaters last about 10 to 12 years. Hard water, lack of maintenance, and heavy use can shorten the life of the tank.

Why is my water heater making popping noises?

Popping or rumbling sounds usually mean there is sediment on the bottom of the tank. As water heats under the sediment, it makes noise. A professional flush can often fix this and help the heater run more quietly and efficiently.

Do I need yearly maintenance on my gas water heater?

Yes. A yearly check can catch small problems before they turn into leaks or breakdowns. A plumber can test the burner, check safety controls, flush the tank, and inspect the venting to keep your heater working safely.