Post By Admin
July 10, 2025After a long, exhausting day, nothing beats the comfort of a warm shower—your water heater makes it all possible.
But what happens when it suddenly stops working? Yep, just like that—thanks to things like corrosion or worn-out parts.
Don’t worry, you’re not alone! In this article, we’ll walk you through the common causes and practical fixes.
As one of the trusted hot water services providers, we’re here to help you get that hot water flowing again in no time.
Common Causes of Corrosion in Water Heater
Rust on a water heater is a headache. Let’s discuss the common causes of a corroded water heater:
1. Sediment Buildup
Over time, minerals from your water supply can settle at the bottom of the tank, creating what’s known as water heater sediment.
This buildup not only reduces efficiency but also traps heat, which can lead to internal rusting and tank damage.
2. Anode Rod Deterioration
Your water heater comes with a sacrificial anode rod that’s designed to attract corrosion and protect the tank. Once it wears out, the tank walls become the next target for rust and decay.
3. High Water Pressure
Consistently high water pressure can weaken the internal lining of your water heater, allowing corrosion to creep in.
If you’ve noticed your water pressure gone low lately, it could be a sign of deeper internal damage caused by earlier pressure issues.
4. Ageing Unit
Just like any appliance, water heaters have a lifespan. If yours is approaching the end of its hot water lifespan, corrosion becomes more likely as parts naturally wear down and lose their protective coating.
5 Signs That Your Water Heater Has Corrosion Issue
Wondering if something’s off with your water heater? Corrosion doesn’t happen overnight, but there are clear signs when it starts creeping in.
1. Discoloured or Rusty Water
Ever turned on the hot tap and noticed the water looks brownish or a little rusty? That’s not normal—and it’s usually a sign of corrosion on water heater parts. It often starts inside the tank or pipes, so don’t ignore it!
2. Strange Metallic Odours
If your hot water smells weird—like metal or something musty—there’s a good chance your tank is rusting from the inside. Corrosion can mess with water quality more than you think.
3. Leaks Around the Base
Spotting water around the base of your heater? That could mean the tank has started to rust through. Corrosion eats away at the metal over time, and those little leaks can turn into big problems fast.
4. Unusual Noises
Hear popping or rumbling coming from your water heater? That’s not just your house settling. It often means sediment has built up, causing parts to rust and strain. Basically, your heater is trying to tell you something.
5. Temperature Inconsistencies
Does your shower go hot and cold without warning? Corrosion could be messing with your water heater’s ability to work properly, leading to annoying temperature swings.
How to Fix and Prevent Corrosion in Your Water Heater
Corrosion doesn’t have to spell the end for your water heater. With the right care and a few preventative steps, you can keep it running well for years. Let’s go over how you can fix existing issues and avoid new ones.
1. Flush the Tank Regularly
As you already know, sediment is a big problem you should get rid of quickly. It reduces heating efficiency, and in the end, it does more harm than good.
Flushing your tank regularly prevents these issues and extends your water heater’s life.
How to do it:
- Turn off the power or gas supply to your water heater.
- Shut off the cold water inlet valve.
- Connect a garden hose to the drain valve at the bottom of the tank.
- Place the other end of the hose in a safe draining area (like a floor drain or outside).
- Open the valve and let the water drain completely.
- Briefly turn the cold water on to flush remaining sediment.
- Close the valve, remove the hose, and turn everything back on.
Tip: This should be done at least once a year, especially in areas with hard water.
2. Replace the Anode Rod
This little hero inside your tank works hard behind the scenes to prevent rust. But just like batteries, it doesn’t last forever.
Checking and replacing it is one of those small jobs that makes a big difference.
How to do it:
- Turn off your water heater and release pressure from the tank.
- Locate the anode rod on the top of the unit.
- Use a wrench to loosen and remove it.
- Inspect the rod—if it’s very thin or coated in calcium, replace it.
- Install the new rod and tighten it securely.
- Restore power and water supply.
3. Inspect for Rust or Leaks
Water heaters don’t usually shout when something’s wrong—but a quiet puddle or subtle rust mark is definitely its version of a cry for help.
How to do it:
- Look for puddles or dampness around the base of the heater.
- Check the seams and valves for rust stains or moisture.
- If you find leaks, shut off the unit and call a plumber for inspection.
- For minor external rust, clean and paint over it to slow further damage.
Tip: Use a flashlight to check around the base, seams, and valves regularly.
4. Soften Hard Water
Hard water might sound harmless, but it’s like junk food for your water heater—too much of it, and things start breaking down. Installing a softener helps stop mineral buildup before it starts.
How to do it:
- Get a water hardness test kit or ask your plumber for a test.
- If needed, install a whole-house water softener near your main water line.
- Regularly maintain the softener (add salt and clean it as instructed).
- Flush your tank more frequently in hard water areas.
Tip: If your soap doesn’t lather well or you notice mineral deposits on fixtures, you likely have hard water.
5. Schedule Professional Maintenance
Even if you’re handy, there are things better left to trained eyes. Having a plumber service the hot water system each year helps catch problems early and keeps your unit in top shape.
What you need to do:
- Contact a licensed plumber at least once a year.
- Ask them to check the anode rod, thermostat, pressure valve, and tank lining.
- Request a full flush and inspection for any rust or corrosion.
- Follow any recommendations for repairs or part replacements.
FAQ about Water Heater Corrosion
1. Is corrosion on a water heater bad?
Yes, corrosion is a serious issue. It weakens the tank and internal components. It leads to leaks, reduced efficiency, and even system failure if left untreated.
2. Does a rusty water heater need to be replaced?
Not always. If the rust is limited to parts like the anode rod or valves, they can be replaced. But if the tank itself is corroding, it’s usually safer and cheaper to install a new unit.
3. What is the best way to get rid of rust in a hot water heater?
Flushing the tank helps remove sediment and rust buildup. Also, replacing the anode rod and scheduling routine maintenance are key to keeping rust under control.
Conclusion
Rust doesn’t have to ruin your day—or your water heater. With a little care and the right help, you can keep the hot water flowing safely.
At Neighbourhood Plumbing, we’re here to make it easy—whether you need repairs, a system check, or expert advice. Let’s fix it together!
About the Author
From unclogging the toughest drains to repairing leaking toilets, Ricky is a seasoned plumber who has brought his craftmanship to homes across Melbourne. He is passionate about sharing plumbing tips just as much as he is about fixing your plumbing issues. So, when your taps or pipes begin leaking, you know who to call.
