Library/Plumbing & Water/Water Heater

Water Heater Maintenance Guide

Most tank water heaters get ignored until something goes wrong. A little maintenance changes that. Spend an hour or two on it each year, and you can help the unit run cleaner, heat more efficiently, and avoid the kind of leak that shows up at the worst possible time.

At a Glance

Difficulty: Intermediate
Time Required: 1 to 2 hours
Frequency: Annually, with a few quick checks every few months
Estimated Cost: DIY: $20 to $80; Pro: $150 to $400

Routine Maintenance Schedule

Task	Frequency	DIY or Pro?
Check for leaks, corrosion, and moisture around the tank	Monthly	DIY
Verify water temperature setting	Quarterly	DIY
Test the temperature and pressure relief valve	Annually	DIY
Flush sediment from the tank	Annually	DIY
Inspect the anode rod	Every 2 to 3 years	DIY/Pro
Inspect venting and burner operation on gas models	Annually	Pro
Inspect wiring and heating components on electric models	Annually	Pro

Safety Warnings

Turn off power at the breaker for electric units or set gas control to pilot/off before starting any maintenance. Never plug, cap, or tamper with the temperature and pressure relief valve; if it leaks continuously or fails to operate, stop and call a pro.

Step-by-Step DIY Guide

Step 1: Shut Off the Heat Source and Water Supply

Start by making the heater safe to work on. Shut off the breaker if the unit is electric. If it runs on gas, turn the control to pilot or off, following the label or owner's manual. Then close the cold-water supply valve above the tank so the heater does not keep refilling while you're working.

Step 2: Inspect the Tank and Surrounding Area

Take a slow look around the whole unit, not just the front. Check the base of the tank, nearby pipes, the shutoff valve, and the drain valve for rust, white mineral crust, damp spots, or fresh drips. If you find water coming from the tank body itself, that usually points to replacement rather than a simple repair.

Step 3: Test the Temperature and Pressure Relief Valve

This valve is a safety device, so it needs to work when called on. Put a bucket under the discharge pipe if needed, then lift the lever briefly and let it snap back. You should get a quick burst of water. If nothing comes out, or the valve keeps dripping after the test, stop there and have it checked by a pro.

Step 4: Drain and Flush Sediment From the Tank

Sediment settles at the bottom of the tank over time, especially in areas with hard water. Attach a garden hose to the drain valve and run the other end to a safe drain location or outdoors where hot water will not cause damage. Open a nearby hot-water faucet, then open the drain valve and let water flow out. If the water looks cloudy or gritty, keep flushing until it runs clearer.

Step 5: Check the Anode Rod

The anode rod is the part that corrodes so the tank lining doesn't have to. After relieving pressure, use a socket wrench to loosen the rod from the top of the heater and pull it out. If it is badly worn, thinned down, or has more than about 6 inches of core wire exposed, it's time for a new one. Replacing a spent rod can add real life to a tank.

Step 6: Confirm the Thermostat Temperature Setting

A lot of heaters are set hotter than they need to be. Check the thermostat and aim for about 120°F in most homes unless the manufacturer or a specific household need says otherwise. That setting is usually a good balance between comfort, safety, and energy use. On electric models, only open access panels if you're comfortable doing it safely.

Step 7: Refill the Tank and Restore Service

Close the drain valve fully, remove the hose, and reopen the cold-water supply. Leave a hot-water faucet open until the sputtering stops and water runs in a steady stream. That tells you the tank is full again. Only after that should you restore power at the breaker or return the gas control to normal operation.

When to Call a Pro

Water is leaking from the tank body, not just a fitting or valve
The relief valve will not discharge during testing or will not stop leaking afterward
You smell gas, see venting problems, or notice soot around a gas water heater
Water stays lukewarm, runs rusty, or the unit makes loud popping after flushing
The drain valve, anode rod, or shutoff valve is seized or begins leaking during maintenance
The heater is more than 10 years old and showing corrosion or repeated performance issues

Frequently Asked Questions

How often should a water heater be flushed?

Once a year is the usual schedule for a standard tank water heater. If you have hard water or a lot of sediment, every 6 months is often a better fit.

What temperature should a water heater be set to?

For most homes, 120°F is the sweet spot. It gives you dependable hot water without pushing scald risk or energy use higher than necessary.

How do I know if my water heater has sediment buildup?

Listen for popping or rumbling, watch for shorter hot-water runs, and pay attention to cloudy or rusty water. Those are classic signs sediment is building up inside the tank.

What does the anode rod do?

The anode rod is basically the tank's bodyguard. It attracts corrosive minerals so the inside of the water heater doesn't take the hit first.

Can I maintain a gas and electric water heater the same way?

A lot of the basic upkeep is the same, including checking for leaks, testing the relief valve, and flushing sediment. Gas units also need burner and venting checks, while electric models need safe inspection of electrical parts.

When should a water heater be replaced instead of repaired?

If the tank itself is leaking, replacement is usually the call. The same goes for units around 10 to 15 years old that keep rusting, losing performance, or needing one repair after another.