Don't Wait for a Cold Shower to Tell You
Hot water systems don't usually fail overnight. They give off warning signs for weeks or months before they pack it in completely. Catching these early means you can plan the replacement on your schedule — not in a panic on a Sunday morning.
Here are the 7 most common signs Perth homeowners miss.
1. The System Is Over 10 Years Old
Most hot water systems have a lifespan of 8–12 years for electric storage tanks, 10–15 years for gas systems, and 15–20 years for solar. If your system is approaching or past these ages, it's living on borrowed time — even if it still works.
You can usually find the manufacture date on the compliance plate attached to the unit. If you can't find it, ask a plumber to check — they can often tell by model number.
2. Rusty or Discoloured Water
If the hot water running from your taps looks brown, orange, or has a metallic smell, the tank lining is corroding internally. This is not a maintenance fix — it means the tank is failing and needs replacing.
Note: discoloured cold water points to a different problem (your pipes or the mains). If it's only the hot water that's affected, it's the system.
3. Water Around the Base of the Tank
A puddle or consistent damp patch around the base of your hot water unit means the tank is leaking. This could be a small relief valve discharge (sometimes normal on hot days) or a cracked tank — which cannot be repaired and must be replaced.
If you notice water around the base, turn off the cold water inlet and call a licensed plumber the same day.
4. Running Out of Hot Water Faster Than Usual
If a household that used to comfortably handle two showers is now running cold mid-way through the first, the heating element (electric) or burner (gas) is losing efficiency. Sediment build-up in the tank reduces capacity over time.
Sometimes a plumber can flush the tank to extend its life by a year or two, but if the system is already old, replacement is usually the better investment.
5. Unusual Noises
Popping, rumbling, or banging sounds coming from your hot water unit are caused by sediment build-up on the heating element. As water heats and bubbles through the sediment layer, it creates noise. This reduces efficiency and accelerates wear.
6. Pressure Relief Valve Keeps Releasing
The temperature and pressure (T&P) relief valve is a safety device that releases water if the system overheats or over-pressurises. A small amount of dripping on very hot Perth days is normal. But if it's constantly discharging or you notice it has corroded shut (equally dangerous), the system needs attention immediately.
Never block or cap a T&P valve — it prevents catastrophic tank failure.
7. Increasing Energy Bills
A declining hot water system works harder and longer to heat the same amount of water. If your electricity or gas bill has crept up without an obvious cause, your ageing hot water system may be the culprit. A modern heat pump system can reduce hot water energy costs by up to 65% compared to a standard electric storage tank.
What's the Cost to Replace in Perth?
| System Type | Supply & Install (Perth) |
|---|---|
| Electric storage (250L) | $1,200–$2,000 |
| Gas storage (170L) | $1,500–$2,500 |
| Gas continuous flow (instantaneous) | $1,800–$3,000 |
| Solar hot water (rooftop) | $3,000–$6,000 |
| Heat pump | $3,000–$5,500 |
Federal and WA government rebates are available for heat pump and solar systems. Ask your plumber about current STC (Small-scale Technology Certificate) rebates — these can reduce the upfront cost by $300–$1,000 depending on your location and system size.
Which System Should You Choose?
For most Perth households, a heat pump or gas continuous flow system offers the best combination of running costs and reliability. Perth's warm climate makes heat pumps especially efficient — they work better here than almost anywhere else in Australia.
Read our full Hot Water Systems Buying Guide for a detailed comparison, or find a licensed Perth plumber to assess your specific situation.