Most homeowners in Fort Myers have never flushed their water heater. The ones who don’t eventually pay for it — either through a failed water heater 5 years early, or a flooded garage when the tank rusts through from the inside out.

This is a particularly Florida problem. Lee County’s water supply contains high levels of dissolved minerals — primarily calcium and magnesium. As water heats, these minerals precipitate out of solution and settle at the bottom of your tank as sediment. Over time, that sediment layer gets thicker, insulates the heating element from the water, forces the burner to run longer, and eventually causes the bottom of the tank to overheat and fail.

The fix is straightforward: flush the tank once a year. Here’s everything you need to know.

How Sediment Damages Your Water Heater

Think of sediment as a blanket on the bottom of your water heater tank. Your gas burner or electric element has to push heat through that blanket to warm the water above it.

This causes three problems:

Higher energy bills. The Department of Energy estimates sediment buildup can increase water heater energy consumption by 10–25%. In a hot-water-heavy Florida household, that adds up fast.

Popping and rumbling sounds. That knocking sound your water heater makes is water trapped beneath the sediment layer expanding as it heats. It’s not dangerous immediately, but it’s a sign the buildup is severe and the tank is working too hard.

Shortened tank life. The average tank water heater lasts 8–12 years. In Lee County with no maintenance, that drops. With annual flushing, many tanks last 12–15 years.

How Often to Flush — The Florida Answer

The standard recommendation is once a year. In Southwest Florida, with our harder water, I’d say:

Annual flush if you’re on city water (Cape Coral, Fort Myers, Bonita Springs)
Every 6 months if you’re on well water, which tends to carry more minerals and iron

Check your anode rod every 3–4 years while you’re at it (see below).

What You’ll Need

Garden hose (long enough to reach a floor drain or outside)
Flathead screwdriver
Work gloves (the water will be hot)
30–45 minutes

How to Flush Your Water Heater: Step-by-Step

Step 1: Turn Off the Heat Source

Gas water heater: Turn the thermostat dial to “PILOT” — don’t turn it all the way off, just pilot mode. This stops the burner without extinguishing the pilot light.
Electric water heater: Turn off the circuit breaker for the water heater at your main panel.

Step 2: Let It Cool (Optional but Recommended)

The water in a tank water heater sits at 120–140°F. If you’re doing this during the day after it’s been heating all morning, the water coming out will scald you instantly. You can wait 2 hours, or just be careful with the hose direction.

Step 3: Connect a Garden Hose to the Drain Valve

The drain valve is near the bottom of the tank — it looks like an outdoor spigot. Connect your garden hose to it and run the other end to:

A floor drain
Outside the garage door (away from plants — hot sediment water will kill landscaping)
Into a large bucket if you want to see what’s coming out

Step 4: Open a Hot Water Faucet Somewhere in the House

Open any hot water faucet — a bathroom sink works fine. This prevents a vacuum from forming in the tank that would stop water from draining. Leave it open the entire time.

Step 5: Open the Drain Valve and Flush

Turn the drain valve counterclockwise. Water will start flowing. It will likely be brown, rust-colored, or cloudy at first — that’s the sediment. Let it run until the water coming out runs clear.

If it drains very slowly or barely at all, you have heavy sediment blocking the valve. Try this: turn the cold water supply back on briefly to stir up the sediment, then drain again. Repeat until it flows clear.

Step 6: Rinse with Cold Water Supply

With the drain valve still open, turn the cold water supply back on briefly. This stirs and flushes out any remaining sediment. Turn it off again and let it drain completely.

Step 7: Close the Drain Valve and Refill

Close the drain valve (clockwise, don’t overtighten — these plastic valves crack). Turn the cold water supply back on fully. Let the tank fill — you’ll know it’s full when steady water comes out of that hot water faucet you left open. Close the faucet.

Step 8: Restore Heat

Gas: Turn the thermostat from PILOT back to your desired temperature setting (120°F is recommended — hot enough to kill bacteria, cool enough to prevent scalding).
Electric: Flip the breaker back on. The element will heat the fresh water — give it 45–60 minutes before expecting hot water.

Check Your Anode Rod

While you have things partially disassembled, consider checking the anode rod — a magnesium or aluminum rod that sits inside the tank and sacrificially corrodes to protect the tank lining.

The anode rod is typically on top of the water heater, under a plastic cap or hex bolt. Use a 1-1/16” socket to remove it. If it’s:

Less than 1/2” in diameter or heavily pitted: Replace it ($25–$50 at any hardware store)
Coated in white calcium deposits: Replace it

A healthy anode rod is what prevents your tank from rusting from the inside. Neglect it and you’ll pay for a new tank.

When to Call a Plumber Instead

Don’t DIY the flush if:

The drain valve leaks and won’t close after draining (common on older brass valves)
The tank is more than 10 years old and has never been flushed — sediment may be load-bearing at this point, and flushing it can actually reveal structural weakness
You see rust on the outside of the tank or at any fittings
You smell rotten eggs in your hot water (sulfur bacteria — this is a water treatment issue)

Tankless Water Heaters in Florida

Tankless (on-demand) water heaters have become more popular in Fort Myers and Cape Coral. They’re more efficient and don’t accumulate sediment the same way — but they need their own maintenance.

With hard Florida water, the heat exchanger in a tankless unit will accumulate calcium scale over time. Many manufacturers recommend descaling (flushing with a white vinegar solution through the heat exchanger) annually in high-mineral-content water areas like Lee County.

If you have a tankless unit and haven’t descaled it in 2+ years, it’s time.

Water Heater Lifespan: When to Replace

Age	Condition	Recommendation
Under 8 years	No rust, drains clear	Maintain, you’re fine
8–12 years	Minor rust at fittings	Monitor closely, budget for replacement
10+ years	Heavy sediment, rust	Replace proactively
Any age	Active leak or tank rust	Replace immediately

New water heaters range from $800–$1,500 installed for a standard tank unit. Heat pump water heaters (more efficient, rebate-eligible) run $1,200–$2,000 installed but can cut water heating costs by 60%.

Frequently Asked Questions

How often should I flush my water heater in Fort Myers? Once a year on city water, every 6 months on well water. Lee County and Cape Coral water has high mineral content that accelerates sediment buildup.

What does the water heater sediment sound like? A popping, rumbling, or crackling sound — especially when it’s heating up. That’s water boiling under and through the sediment layer.

Can I flush my water heater myself? Yes, if the tank is in reasonably good condition and the drain valve works. If the valve won’t seal after draining, or the tank is older than 10 years with heavy sediment, call a plumber.

What temperature should my water heater be set to? 120°F is the recommended setting. Above 120°F increases scalding risk; below 120°F can allow Legionella bacteria to grow.

How do I know if my water heater needs replacing? Age (10+ years), visible tank rust, water pooling under the unit, or severely reduced hot water capacity are all signs it’s time.

Brian Cappucci is a Florida Certified General Contractor (CGC1531080) and Realtor (SL3538466) serving Fort Myers and all of Southwest Florida. Need a plumber referral or home inspection? Contact Brian.

When (and How) to Flush Your Water Heater in Southwest Florida