Water Heater Sediment Cost Calculator
How Much Are You Losing?
Most people don’t think about their water heater until the hot water runs out too fast, or it starts making strange noises. But if you’ve never flushed your water heater, you’re silently paying the price-every day. It’s not a luxury. It’s not optional. Skipping this simple task is like never changing your car’s oil. Eventually, something breaks, and it breaks hard.
The silent killer inside your tank
Your water heater pulls in cold water from the mains, heats it up, and stores it. Sounds simple, right? But that water isn’t clean. Even in Perth, where tap water is among the best in Australia, it carries tiny particles of sand, rust, minerals like calcium and magnesium, and other debris. Over time, these settle at the bottom of the tank. That’s sediment. And it doesn’t just sit there quietly.Every time your heater turns on, the heating element or gas burner has to work harder to push heat through that thick layer of gunk. Think of it like trying to boil water with a blanket wrapped around the pot. The result? Higher energy bills, longer wait times for hot water, and a heater that wears out way faster than it should.
A study by the Water Quality Research Foundation found that just half an inch of sediment buildup can increase energy use by up to 20%. That’s $150-$300 extra per year on your electricity or gas bill, depending on usage. And that’s just the start.
What happens when sediment builds up
- Reduced hot water supply - Sediment takes up space in the tank. So if you’ve got a 50-gallon heater, you might only have 40 gallons of usable hot water left. That means showers get shorter, dishes get cold faster, and laundry takes longer.
- Loud popping or banging noises - When water gets trapped under layers of sediment, it boils and creates steam pockets. That’s what causes the loud popping or rumbling you hear. It’s not just annoying-it’s a sign your tank is under stress.
- Corrosion and tank failure - Sediment holds moisture against the metal lining of the tank. That speeds up rusting. Once the tank corrodes through, you’re looking at a full replacement. And a new water heater? That’s $1,500 to $3,500 in Perth, depending on type and installation.
- Lower water temperature - The sediment acts like insulation. Heat can’t transfer efficiently, so even if your thermostat is set to 60°C, the water coming out might only be 45°C. You might crank the heat higher, which makes everything worse.
- Broken dip tube or heating element - Sediment can clog the cold water inlet (the dip tube), causing uneven heating. In electric models, sediment can cover the lower heating element, causing it to overheat and burn out. Replacing a heating element costs $200-$400. Replacing the whole tank? Five times that.
How often should you flush your water heater?
Most manufacturers recommend flushing your water heater at least once a year. If you live in an area with hard water-like parts of Perth’s eastern suburbs-you should do it every six months. Hard water means more minerals. More minerals mean faster sediment buildup.
Here’s what happens if you wait too long:
- After 2 years: Noticeable drop in hot water volume. Slight noises.
- After 4 years: Consistent banging, longer heating times, higher bills.
- After 6+ years: High risk of tank failure. Corrosion may already be inside the walls.
Water heaters last 8-12 years on average. Flush them regularly, and you can hit the 12-year mark. Skip it? You’re lucky to get 6.
How to flush your water heater (simple steps)
You don’t need a plumber. You don’t need special tools. You just need a garden hose, gloves, and 30 minutes.
- Turn off the power. For electric heaters, flip the breaker. For gas, turn the dial to "Pilot".
- Turn off the cold water supply valve at the top of the tank.
- Attach a garden hose to the drain valve at the bottom. Run it to a floor drain, outside, or a large bucket.
- Open a hot water tap somewhere in the house. This lets air in and helps the water flow out.
- Open the drain valve and let the water run. It’ll come out cloudy at first-full of sediment. Keep going until it runs clear.
- Close the drain valve, remove the hose, turn the cold water back on, and refill the tank.
- Once full, turn the power or gas back on.
Pro tip: If the water doesn’t drain easily, your valve might be clogged. Don’t force it. Call a pro. A blocked drain valve is a sign your heater is older and needs more attention.
Signs you’ve waited too long
If you’ve never flushed your heater and you’re seeing any of these, you’re in damage control mode:
- Hot water runs out in under 10 minutes
- You hear loud popping, cracking, or rumbling
- The water smells like rotten eggs (sulfur bacteria thrive in sediment)
- Water coming out is discolored-brown, yellow, or rusty
- Your heater is over 8 years old and you’ve never maintained it
These aren’t "maybe fix it" problems. They’re red flags. A corroded tank can leak suddenly. A failed heating element won’t come back. And if your heater bursts? Water damage to your floor, walls, and ceiling can cost thousands.
What about tankless water heaters?
If you’ve got a tankless unit, you’re not off the hook. These systems don’t store water, but they still pull in minerals. Over time, those minerals build up inside the heat exchanger. Manufacturers recommend flushing tankless heaters every 1-2 years with a vinegar solution. Skip it, and your unit will overheat, reduce output, or die early.
Many people assume tankless means maintenance-free. It doesn’t. It just means the maintenance is different.
Why most people skip flushing
It’s not laziness. It’s ignorance. Most people think their water heater is "set it and forget it." They don’t know it’s a machine with moving parts, even if it’s just a tank of water and a heater. They don’t realize sediment is a silent killer. And they don’t know how cheap and easy flushing is.
Compare it to changing your air filter. You don’t wait until your AC stops working. You do it before it fails. Same with your water heater.
The real cost of ignoring it
Flushing your water heater costs you $0 in parts. Maybe $10 if you buy a new drain valve. And 30 minutes of your time.
Not flushing? You could be looking at:
- $200-$500 in extra energy bills per year
- $300-$600 to replace a broken heating element
- $1,800-$3,500 for a full replacement
- Water damage repair: $2,000-$10,000 if the tank bursts
That’s not a gamble. That’s a guaranteed loss.
Final thought: Do it now
If you’ve never flushed your water heater, today is the day to start. Don’t wait for the noise. Don’t wait for the cold shower. Don’t wait for the leak.
It’s not a big job. It’s not scary. It’s just something you need to do-like brushing your teeth or changing your smoke detector batteries. Your water heater won’t thank you now. But when you step into a hot shower next winter, and it lasts longer than ever before, you’ll know why.