How To Look At A House

McGarry and Madsen's home inspection blog for buyers of  

site-built, mobile/manfuactured and modular homes

Why is my water heater making strange (rumbling, gurgling, knocking or banging) noises?

Friday, August 10, 2018

We have even heard it called a burping sound. Fixing the problem is as simple as draining the sediment/mineral buildup from the tank, which is the cause of the problem and also the purpose of a small faucet at the bottom of the tank. When there is a heavy layer of crud on the floor of the tank, heat is trapped under it that intermittently pushes through the layer and escapes with a bubbling—or sometimes even a wheezing—sound effect. Here’s the steps to follow to get your silent water heater back: 

  1. Shut off the the water heater, either by turning the thermostat dial on a gas water heater to “PILOT,” or turning off the breaker on an electric water heater. 
  2. Attach a garden hose to the faucet at the base of the water heater. Run the end of the hose outside to a location that will not be harmed by the hot water, which can kill grass or the roots of landscape plants where it drains. If you can’t easily find a satisfactory spot for the hot water to drain without damaging your yard, then run the hot water at sink for a while until it cools down.
  3. Close the valve on the cold water supply pipe of the water heater, to shut off the water flow to the tank.
  4. Open a hot water faucet at a nearby sink. This will allow air flow backwards into the tank so that it will drain easier.
  5. Open the hose faucet valve and let the tank drain completely.
  6. Close the hose faucet and let the tank refill, leaving the sink faucet open for a while. You will get a sputtering mixture of water and the air that is being pushed back out of the tank for a while. When the water runs continuously at the sink, without any sputtering, shut off the sink faucet.
  7. Turn up the thermostat on the gas water heater, or switch on the breaker at an electric water heater, put the hose away, and you are done.  
  8. If the hose faucet drips and does not close completely, there is likely some sediment residue stuck in the valve. You may have to repeat the flushing operation one more time.

   It’s a sensible maintenance idea to drain your water heater every two years, which will both prevent the annoying sounds and extend the life of the tank. If the flushing operation is more than you want to tackle, a professional plumber can do the job for you, along with a doing a general maintenance check to make sure there are no other problems.

    Also see our blog post Why is there water in my water heater drain pan?

   Visit our WATER HEATERS page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.

Water Heaters

Water Heater Age

Wells

Septic Tank Systems

Structure and Rooms

Plumbing Pipes

Termites, Wood Rot

& Pests

Sinkholes

Stairs

When It First

Became Code

"Should I Buy A..."

Park Model Homes

Site

Shingle Roofs

Safety

Stucco

Remodeling

Wind Mitigation

Roof and Attic

"Does A Home

Inspector...?"

Pool and Spa

"What Is The Difference Between..."

Radon

Brick

Plumbing

Concrete and

Concrete Block

Metal Roofs

Foundations

Modular Homes

Rain Gutters

Mold, Lead & Other Contaminants

Condominiums

Older and

Historic Houses

Crawl Spaces

Mobile-Manufactured Homes

Building Permits

Life Expectancy

Clay Soil

Insurance

Floors

Insulation

Toilets

Exterior Walls

& Structures

Generators

Common Problems

HUD-Code for

Mobile Homes

Garages and Carports

Flat (Low Slope) Roofs

Electrical Panels

Sprinkler Systems

Electrical Receptacle Outlets

4-Point Inspections

Hurricane Resistance

Frequently Asked Questions (FAQ)

Home Inspection

Heating and Air Conditioning

Building Codes

Fireplaces and Chimneys

Inspector Licensing

& Standards

Energy Efficiency

Washers and Dryers

Electrical

Kitchens

Doors and Windows

(placeholder)

Cracks

Electrical Wiring

Click Below  

for Links

to Collections

of Blog Posts

by Subject

Plumbing Drains

and Traps

Appliances

Smoke & CO Alarms

Aging in Place

Top 5 results given instantly.

Click on magnifying glass

for all search results.

Bathrooms

Lighting

AFCI, CAFCI,

DFCI, & GFCI

Sinks

Air Conditioner & Furnace Age/Size

Attics

Electrical Switches

Siding

Search

This

Site

Water Intrusion

Electrical - Old

and Obsolete

(placeholder)

Foundation Certifications

Tiny Houses

About Us

(placeholder)