Water Heater Making Rumbling Noise

Your house is completely quiet at night. Suddenly, you hear a loud sound coming from the basement. It sounds like heavy rocks rolling around in a metal dryer. A water heater making rumbling noise is a very scary thing for a homeowner. The big metal tank sounds like it wants to explode. This loud noise is actually a very common plumbing problem. It means your heavy machine is full of thick dirt and needs a deep cleaning fast.

The Boiling Mud Problem

Hard Water Minerals

City tap water is never perfectly clean. It carries tiny invisible pieces of heavy rock and minerals. You cannot see these rocks when you drink a glass of water. Over many years, these heavy minerals fall to the very bottom of your metal heating tank. They mix together and turn into a thick layer of heavy mud. Check the EPA Drinking Water page to learn what floats in your city water.

Trapped Heat Bubbles

Your massive gas fire sits right under this layer of thick mud. The fire tries to heat the pure water above the dirt. The mud traps the intense heat from the fire. The small amount of water trapped under the mud starts to boil very hard. The boiling water bubbles push up through the heavy mud layer. This popping and bubbling creates the terrible rumbling noise in your basement.

How To Fix The Noise

Flushing The Dirty Tank

You must get all this heavy mud out of your metal tank. You need to attach a garden hose to the brass valve near the bottom of the machine. You open the valve and let the dirty water run outside into the street. The water will look very brown and ugly at first. You must let it run until the water looks perfectly clear again. Read our Tankless Water Heater Flush Cost guide to learn about cleaning modern wall machines.

Checking The Anode Rod

Your large metal tank has a special metal stick hiding inside. This long stick is called an anode rod. It attracts all the bad rust and heavy minerals to protect the steel tank walls. This stick gets completely eaten away over five years. A professional worker can slide a brand new stick into the top of the machine. Read our What Is A Water Heater Anode Rod page to see why this metal stick is so important.

Average Repair Costs

System Component	Main Purpose	Expected Lifespan	Estimated Part Cost	Estimated Labor Cost
Brass Drain Valve	Lets dirty water out	10-15 years	$15 to $30	$100 to $150
Magnesium Anode Rod	Protects the steel tank	3-5 years	$30 to $60	$150 to $200
Gas Control Valve	Feeds fuel to the fire	10-15 years	$150 to $300	$200 to $400
New Water Heater	Replaces the rusty tank	10-12 years	$600 to $1200	$500 to $800

When To Call A Pro

Sometimes the heavy mud sits in the tank for way too long. The boiling water destroys the bottom of the metal tank. The steel walls get very thin and rusty. A rusty tank will eventually pop open and flood your entire basement with fifty gallons of water. A professional plumber will tap the bottom of the tank to see if the metal is safe. Review the Energy.gov Water Heating page to learn about buying a brand new safe machine. Use our HVAC Calculators to figure out what size tank your family needs.

Is your heavy tank making a massive banging noise right now? Do you see brown rusty water leaking onto your basement floor? Our expert plumbing team can safely drain your dangerous tank today. We carry brand new metal rods and heavy brass valves in our work trucks. We will make your hot water safe and quiet again.

Need Help Paying?

Buying a brand new fifty gallon tank costs a lot of unexpected money. We offer easy online loans to help you pay for safe plumbing repairs. You can pick a very small monthly payment that fits your budget perfectly. We make the approval process very simple for you.

FAQ

Why is my water heater making a loud rumbling noise at night?

The loud noise happens because boiling water bubbles are fighting to escape from under a massive layer of thick mineral mud at the bottom of your tank.

Is a rumbling water tank dangerous for my house?

A loud tank will not explode like a bomb but the trapped boiling heat can crack the rusty bottom and cause a massive flood in your basement.

Can I flush the heavy mud out of the tank myself?

Yes, you can safely attach a regular garden hose to the bottom brass valve and run the dirty brown water out into your driveway until it flows totally clear.

How much does it cost to replace a completely rusted metal tank?

A professional plumbing worker will usually charge between $1000 and $2000 total to buy a brand new heavy tank and install it safely in your basement.

How often should I clean the dirt out of my hot water machine?

You should flush the heavy minerals out of the bottom of the tank every single year to keep the machine perfectly quiet and save money on your gas bill.

Conclusion

A loud banging noise from the basement is a cry for help. Your heavy machine is choking on thick mineral dirt. You must attach a hose and flush the brown mud out into the street. Check your metal protection rod to see if it is completely eaten away. Look closely at the floor for dangerous rust leaks. A professional worker can flush your system and check the metal for about $150. Use our Plumbing Services page to get safe help right away.