What Are the Red Flags on a Water Heater? Signs You Need Immediate Repair

Water heaters don’t scream for help-they just stop working, or worse, start leaking. By the time you notice something’s wrong, it’s often too late to avoid a big mess or a full replacement. In Toronto winters, a broken water heater isn’t just inconvenient-it’s dangerous. You don’t need to be a plumber to spot the warning signs. Here are the real red flags that mean your water heater is on its last legs.

Water leaking from the tank

If you see water pooling under your water heater, stop what you’re doing. This isn’t a minor drip. A small leak around the pressure relief valve might be fixable, but water coming from the tank itself? That’s corrosion eating through the steel lining. Most tank-style water heaters last 8 to 12 years. If yours is older than that and leaking from the body, it’s not repairable. The tank has rusted from the inside out. No patch, no sealant, no magic fix will work. You’ll need a replacement. Waiting only increases the risk of a sudden flood-especially if the leak is near electrical wiring or your basement floor.

Rusty or discolored hot water

Turn on your hot tap and let it run for a minute. If the water comes out brown, orange, or reddish, that’s rust. It’s not from your pipes-it’s coming from inside the tank. The glass lining that protects the steel tank has cracked or worn away. Once that happens, water touches the metal, and rust forms. Over time, the rust builds up, clogs your showerhead, stains your sinks, and weakens the tank. This isn’t just a cosmetic issue. Rust means the tank is corroding. If you’re seeing this and your heater is over 8 years old, replacement is your only safe option.

No hot water-or not enough

If your water heater suddenly stops heating, don’t assume it’s the thermostat. First, check the power. For electric models, make sure the circuit breaker hasn’t tripped. For gas units, confirm the pilot light is still on. If both are fine and you’re still getting cold water, the heating element (electric) or burner assembly (gas) has likely failed. But here’s the catch: if you’re getting lukewarm water that runs out in 10 minutes, that’s a sign the dip tube has broken. The dip tube sends cold water to the bottom of the tank. When it cracks, cold water mixes with hot water right at the top, making your shower feel like a tepid bath. Replacing the dip tube is cheap. But if the tank’s old, it’s probably not worth the fix.

Loud noises coming from the tank

That popping, rumbling, or banging sound? It’s not your imagination. It’s sediment. Over time, minerals in the water settle at the bottom of the tank. As the water heats up, it gets trapped under this layer and boils. That’s what makes the noise. It’s not just annoying-it’s damaging. Sediment acts like insulation, forcing the heating element to work harder. That burns out the element faster and wastes energy. In extreme cases, the sediment layer can overheat the tank bottom and cause cracks. Flushing the tank once a year can prevent this. But if you’ve ignored it for years and the noise is loud and constant, the damage may already be done. A noisy heater with poor hot water output? That’s a warning you’re running on borrowed time.

Smell like rotten eggs

That sulfur smell-like rotten eggs-isn’t from your drain. It’s from bacteria in the water reacting with the magnesium anode rod inside the tank. The anode rod is there to protect the tank from rust by attracting corrosive elements. But over time, sulfate-reducing bacteria can grow, especially in warm, stagnant water. It’s not harmful, but it’s unpleasant. The fix is simple: replace the anode rod with an aluminum-zinc version, or flush the tank with hydrogen peroxide. But if the smell returns quickly, or if you also see rusty water, the tank itself may be corroding. That’s when you need to think about replacement, not just cleaning.

Age of the water heater

Most water heaters in Canadian homes last between 8 and 12 years. If yours is 10 or older and you’re seeing any of the above signs, you’re not dealing with a repair-you’re dealing with a countdown. Manufacturers don’t make them to last forever. Even if it’s still working, an old tank is a liability. In Toronto, where pipes freeze and water pressure is high, older units are more likely to fail suddenly. A 15-year-old water heater that hasn’t been flushed in years? It’s a time bomb. Replacing it before it breaks saves you from water damage, emergency service fees, and the stress of a cold shower in January.

High energy bills with less hot water

If your heating bill has crept up over the last year but you’re getting less hot water, your heater is struggling. Sediment buildup, failing elements, or poor insulation all force the system to work harder. That means more electricity or gas used for less output. Compare your bills year-over-year. A 20% increase in energy costs with no change in usage? That’s a red flag. It’s cheaper to replace an old, inefficient heater than to keep paying extra to run it. Newer models are up to 30% more efficient. The payback period? Often under two years.

When to call a professional

You don’t need to be an expert to spot these signs. But once you do, don’t delay. A small leak can turn into a flooded basement in hours. Rusty water means internal damage is already happening. No hot water in winter? That’s a health risk. If you see more than one of these red flags, call a licensed plumber. Don’t try to patch it yourself. Water heaters operate under pressure and high heat. DIY fixes often make things worse. A professional can confirm whether it’s a repairable part-or if you need a full replacement. They can also check your water pressure, anode rod condition, and venting system-all things that affect longevity.

What to do next

If your water heater is showing any of these signs, take action now. First, turn off the power or gas supply. Then shut off the water inlet valve. Drain the tank if it’s leaking heavily to prevent further damage. Take photos of the leaks, rust, or damage. These help when you’re getting quotes. Don’t wait for it to fail on a weekend. Start researching replacements now. Look for Energy Star-rated models with a 10-year warranty. Consider tankless options if you have high demand or want long-term savings. In Toronto, where water is hard and winters are harsh, investing in a quality unit makes sense.