First, work out whether it is just the hot water
This one test tells you most of the story. Run a cold tap into a white cup, then run a hot tap into another. If only the hot side is discoloured, the problem lives in your hot water system, almost always the tank. If both are discoloured, the problem is upstream of your house, typically mains flushing, burst main repairs or hydrant use stirring sediment in the street, and it usually clears within hours. If only one tap in the house runs brown, hot and cold, the issue is local to that fixture or its pipe run, often a corroding galvanised section in an older home.
Diagnosing by pattern
| What you see | Most likely source | What to do |
|---|---|---|
| Hot taps only, brown or rusty tinge | Tank corrosion, spent anode | Book an inspection this week |
| Hot and cold both brown, whole house | Mains disturbance in the street | Run an outside tap 5 to 10 minutes, wait a few hours |
| One fixture only, hot and cold | Corroding pipe run or fixture | Plumber inspection, quote on inspection |
| Brown first thing, clears after a minute | Early tank corrosion or pipe sediment | Monitor, book a check soon |
| Brown plus rumbling, popping tank noises | Heavy sediment and corrosion together | Price a replacement now |
| Brown plus water around the tank base | Tank wall failing | Same-day call, isolate the tank |
Why tanks rust from the inside out
Steel storage tanks survive decades of hot water because of two defences, a glass lining bonded to the steel and a sacrificial anode that corrodes instead of the tank. Both are consumables. The lining develops hairline cracks over years of heating and cooling, and the anode is typically consumed within 3 to 5 years, faster in coastal conditions. Once the anode is spent, corrosion starts on the exposed steel, and the rust you are seeing in the shower is the tank wall dissolving into your hot water. The pattern we see on the Gold Coast is consistent: tanks past 10 years with an original anode are where brown hot water shows up.
Is it dangerous, and will it stain?
Rust-tinted water is unpleasant rather than acutely dangerous, iron discolouration at these levels is mainly an aesthetic and taste issue, but do not drink obviously discoloured water and avoid running hot loads of white washing until it is resolved. The real costs are practical. Rusty water stains laundry and fixtures, sediment clogs mixer cartridges, tempering valves and shower heads, and the underlying corrosion always ends the same way, with a leaking or burst tank, usually at the worst possible time. Brown hot water is the cheap warning. A flooded hallway is the expensive one.
Can it be fixed, or is the tank done?
We will always tell you straight after looking. Caught very early, on a younger tank, a new anode and a tank flush can arrest the process, and both are quoted on inspection. But once a tank past 10 years is producing visibly rusty water, replacement is nearly always the honest answer, because the lining and base are already compromised and money spent on that cylinder is money you will spend again soon. As of 2026 on the Gold Coast, replacement runs $1,300 to $2,400 installed for electric storage, $1,800 to $3,200 for gas storage, $1,900 to $3,500 for gas continuous flow, and $2,500 to $4,500 after rebates for a heat pump, with rebates of $1,000 to $2,500 confirmed against current schemes at quote time. Most swaps are done the same day, so brown water on Tuesday does not need to mean cold showers on Wednesday.
If it is the mains, patience and a tap usually fix it
When both hot and cold run brown across the whole house, check whether neighbours have it too and whether your water supplier has logged works in your street. Running an outside tap for 5 to 10 minutes flushes your service line, and the supply usually clears within a few hours of the works finishing. If whole-house discolouration persists for more than a day, call us, persistent discolouration with no mains explanation can point at old galvanised pipework, which is a different conversation about staged replacement.
Brown hot water? Get a straight answer today. Call Hills Plumbing & Gas on 0472 657 042. We are Gold Coast locals, QBCC licensed (licence 15243081), rated 5.0 stars from 27 Google reviews. We will run the diagnosis, quote repair and replacement as fixed prices side by side, and give you an honest ETA on the call. See our hot water systems page.