Why Flush Your Electric Water Heater?
Over time, sediment (minerals like calcium and magnesium) builds up at the bottom of the tank. This can:
Lower efficiency and raise energy bills
Cause popping or rumbling sounds
Reduce hot water supply
Lead to early failure or corrosion
Step-by-Step Guide (Based on This Old House)
- Preparation
Turn off power at the circuit breaker.
Let the tank cool for a few hours to avoid burns.
Shut off cold water supply to the heater.
- Set Up for Draining
Attach a garden hose to the drain valve at the tank’s base.
Route the other end to a safe drainage point (floor drain, outside, or into a bucket).
Open one or two hot water faucets in your home to prevent a vacuum from forming.
- Drain and Flush
Open the drain valve to begin emptying the tank.
Watch the water; if it’s cloudy or contains sediment, proceed to flush.
Use the “on-off” method: briefly turn the cold water supply on and off to stir up and dislodge sediment. Repeat until the water runs clear.
- Refill and Restart
Close the drain valve and remove the hose.
Open the cold water supply to refill the tank, keeping faucets open until water flows steadily to release trapped air.
Once full, restore power at the circuit breaker.
Maintenance Tips & Additional Insights
Frequency: Flush the tank annually; more often if you have hard water.
Anode Rod: Check every few years and replace if heavily corroded to prevent tank rusting.
Pressure Relief Valve: Test annually to ensure it functions correctly.
Temperature Setting: Set to around 120 °F for safety and efficiency.
Signs Sediment Needs Flushing: Noisy operation, rust-colored water, reduced hot water, higher energy bills.
Safety & When to Call a Pro
Safety equipment: Wear gloves and eye protection—especially when handling hot water.
Call a plumber if:
Tank doesn’t drain or water never clears
Leaks, strange noises, or old age (>10–15 years) of heater
At-a-Glance Overview
Step What to Do
Preparation Turn off power & water; let tank cool
Drain Setup Attach hose, open faucets to release air
Draining & Flushing Drain tank; flush with cold water until clear
Refill & Restart Refill, bleed air, restore power
Maintenance Checks Flush annually, check anode, test T&P valve, adjust temperature
Safety & Professional Aid Use protective gear; call plumber for stubborn issues or age-related wear