Quick Answer
Watch for rusty water, banging noises, leaks at the base, lukewarm showers, and rising energy bills. Hot water systems typically last 8–12 years — if yours is older and showing any of these signs, replacement is usually cheaper than waiting for a flood.
Hot water systems rarely fail without warning. The trick is knowing what to look for so you can act before you’re standing in a cold shower at 6am or mopping up a flooded laundry.
1. Rusty or Discoloured Hot Water
If only the hot tap runs rusty water (cold runs clear), the inside of your storage tank is corroding. Once the tank wall fails, you’ll have a flood. Time to replace.
2. Strange Noises
Banging, popping, or rumbling sounds usually mean sediment buildup at the bottom of the tank. The sediment overheats and steam pockets explode — reducing efficiency and damaging the tank.
3. Leaks Around the Tank
Any moisture pooling around the base is bad news. Small drips become floods quickly. If the tank itself is leaking (not just a fitting), replacement is the only option.
4. Running Out of Hot Water Fast
If your morning shower goes lukewarm halfway through, you’ve likely got a failing element (electric) or a sediment-fouled burner (gas). Often repairable if caught early.
5. Age of the System
Storage tanks last 8–12 years. Continuous flow units last 15–20. If yours is at or past its lifespan and showing any other sign on this list, replace before it fails.
6. Rising Energy Bills
A failing element or sediment-coated burner has to work harder to heat the same amount of water. If your gas or electricity bill keeps climbing without explanation, your hot water system is often the culprit.
FAQs
How long does a hot water system last?
Storage tanks: 8–12 years. Continuous flow (instantaneous): 15–20 years. Heat pump: 10–15 years.
Can I replace a hot water system myself?
No — in NSW, hot water installation must be done by a licensed plumber (and a licensed gasfitter for gas systems). DIY work voids insurance and warranties.
Hot Water Trouble in Sydney?
Mr. Clog repairs and replaces all hot water systems — gas, electric, and heat pump. Same-day service across Sydney.