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🍁 Built for Canadian homes — written to Canadian codes and provincial rules. Not intended for use outside Canada.
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Tap water is discoloured or smells off

Off-colour or funny-smelling water is unsettling, but it's often temporary and harmless — sediment stirred up in the main, or just air in the line — and clears on its own.

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Select anything that matches and the checklist below reorders to fit. Not sure? Skip it.
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In Canada, rusty brown or yellow water usually means corrosion — from aging galvanized pipes or the water heater. Rule in cheaply: run the cold tap a few minutes, and check whether it's worse on the hot side or only in the first morning draw. Hot-side-only points at the heater (a flush and anode check can help); persistent rust on the cold side points at the pipes, which is a licensed plumber's job.

Ranked from real-world failure data. The order updates as you select what you’re noticing above.

Likely causes, in the order to check them

Showing the typical order
Beginner-friendly Doable, with care Safety-critical Call a pro

visibilityHow to tell pipe rust from tank rust

  1. Run the COLD tap into a clear glass for a few minutes. If it starts rusty and runs clear, it was likely sediment or the first still water in the pipe; if it stays rusty, corrosion is ongoing.
  2. Now compare hot and cold. If only the HOT is discoloured (or smells of sulphur), the water heater's tank or anode is the likely source. If both hot and cold are rusty, suspect the supply pipes.
  3. Check the first-draw pattern over a couple of mornings. Rust that's worst in the first draw and clears with running points at localized pipe corrosion; a plumber can confirm and locate it.
buildclear-glass schedule10 min

handymanHow to fix it

warning Let the tank cool — the water inside is scaldingA water heater holds many litres of water hot enough to scald in seconds, and the tank is heavy when full. Turn the heater off and let it cool for an hour or two before draining, keep the hose routed to a drain away from your hands and feet, and mind your footing. If wrestling with the anode or the tank isn't for you, a plumber can flush it and swap the anode quickly.

Drain and flush the water heater to clear rust and sediment, and inspect the sacrificial anode — a heavily corroded anode is a cheap swap and often cures a hot-side rust or sulphur smell. Corroded supply pipes, by contrast, are a licensed plumber's repair, not a flush.

  1. Switch the heater to "vacation"/pilot (gas) or OFF at the breaker (electric), and shut the cold-water inlet valve. Let the tank cool for an hour or two so you're not draining scalding water.
  2. Attach a garden hose to the drain valve at the bottom, run it to a floor drain or outside, open a hot tap upstairs to break the vacuum, then open the drain valve and flush until the water runs clear.
  3. To inspect the anode, close the drain, and with the tank still off, unscrew the anode rod from the top (a 1-1/16" socket and breaker bar). If it's heavily eaten down to the wire, fit a new one — switch to an aluminum-zinc anode if you're fighting a sulphur smell.
  4. Close everything up, reopen the inlet, let the tank refill fully (a hot tap will sputter then run steady), then restore power/gas and confirm normal hot water.
schedule60 min savings$20–60
Water-heater sacrificial anode rodMatch the length and thread; choose aluminum-zinc if treating a rotten-egg (sulphur) smell
warning Corroded supply pipes are a plumber's jobYou can safely flush the heater and swap an anode yourself. But if the rust is on the cold side too, or persists after a good flush, the corrosion is in the supply piping — often old galvanized steel. Replacing pipe is a licensed plumber's repair (and in some provinces licensed-only work), not a DIY flush. Route it up rather than chasing it through fixtures.
gavel Check your province first AB: homeowner may do this · BC: homeowner may do this · ON: homeowner may do this · PE: homeowner may do this · QC: homeowner may do this
Flushing the tank, running taps, and replacing the sacrificial anode are owner-permitted maintenance. Replacing corroded supply piping is a licensed plumber's job in most provinces (permit and/or licence); confirm the local rule before treating pipe replacement as DIY.
report On a well, don't assume a sulphur smell is harmless — test itOn municipal water a rotten-egg smell is usually the heater's anode. On a private well the same smell can be nuisance sulphur bacteria — but it can also flag a water-quality problem, so it should be tested, not assumed. Have the well water tested through an accredited lab (your local health unit can point you to one), and use a certified well/water professional for shock chlorination or treatment. If the smell arrived suddenly after flooding or heavy rain, treat it as possible contamination and don't drink the water until it's cleared.
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Why the list is in this order

We don’t sort by likelihood alone. We sort the way a good, honest tradesperson thinks: rule out the free, safe, common causes first. That’s why the cheap checks outrank the expensive repairs — and why anything dangerous gets a hard stop instead of a pep talk. The order exists to save you money, not to sell you anything.