Generic Water Heaters Water Heater Making Popping or Rumbling Noise: How to Fix It Yourself
Popping, rumbling, or crackling sounds from your water heater are caused by sediment buildup on the bottom of the tank. Minerals in the water settle out over time and form a layer on the bottom. When the burner heats the water under this layer, steam bubbles pop through the sediment — that is the noise you hear. Flushing the tank removes the sediment and fixes the noise.
⚠️ Safety First
- The water draining from the tank is very hot. Do not let it spray on your skin.
- Run the hose to a floor drain, outside, or into a large bucket. Hot water can damage plants and grass.
- Turn off the gas or electric power to the heater before draining.
- If the drain valve is stuck, do not force it with too much pressure — old plastic valves can break and cause a flood.
Parts You May Need
Step-by-Step Repair
- 1
Turn off the heat source
For gas water heaters, turn the gas control knob to the Pilot position (this keeps the pilot lit but stops the main burner). For electric water heaters, turn off the breaker. You do not want the heating element or burner running while the tank is partially empty.
- 2
Connect a garden hose to the drain valve
The drain valve is at the bottom of the tank. It looks like an outdoor faucet spigot. Attach a garden hose and run it to a floor drain, outside, or to a bucket. Make sure the hose end is lower than the drain valve so gravity can do the work.
- 3
Open the drain valve and flush
Open a hot water faucet somewhere in the house (this lets air into the system so it drains faster). Then open the drain valve. The water will be murky at first — that is the sediment. Let it run until it comes out clear. If the water is very dirty, close the drain valve, let the tank refill, and drain again.
- 4
Stir up remaining sediment
For heavy sediment buildup, close the drain valve and turn the cold water supply back on briefly with the drain still connected. The incoming cold water will stir up sediment on the bottom. Then open the drain valve again and let it flush out. Repeat this a few times until the water runs clear.
- 5
Close up and restart
Close the drain valve, disconnect the hose, and turn the cold water supply fully on. Open a hot water faucet in the house and let it run until water flows steadily with no air sputtering — this means the tank is full. Then turn the gas back to On or flip the electric breaker back on. The popping noise should be gone or greatly reduced.
If That Didn't Work
- Expansion and contraction of the tank walls (less common, usually harmless)
- High water pressure causing the T&P valve to release (hissing sound)
- Water hammer in the pipes (banging when faucets shut off, not from the heater itself)
When to Call a Professional
If flushing does not reduce the noise, the sediment layer may be too thick and hardened to flush out normally. A plumber can do a more aggressive cleaning or recommend replacement. If the tank is over 10 years old and heavily sediment-clogged, replacement is usually the better investment. Flushing annually prevents this buildup.
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Disclaimer: This guide is for informational and educational purposes only and does not constitute professional repair advice. All repairs are performed at your own risk. RepairItFree.com is not liable for any personal injury, property damage, device damage, voided warranties, or other losses resulting from the use of this information.
If you are unsure about any step — especially anything involving electricity, gas, water, or refrigerant — stop and consult a qualified professional. Your safety is more important than saving money.
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