John Nighingale — Professional Plumber at Plumb It Right
Signs Your Hot Water System Needs Replacing and What to Do Next
Key Takeaways
- •A leaking tank cannot be repaired, but water pooling at the base can also come from a valve, a fitting or condensation, so diagnose the source first.
- •A unit under eight to ten years old with one failed part is usually worth repairing.
- •Rust, sediment and repeated repairs in two years point to replacement.
- •Gas hot water faults need a licensed gas fitter, and DIY gas work is illegal in WA.
Your hot water runs out, the repair bill arrives, and two months later it happens again. At some point you stop fixing and start throwing money at a dying system. Here is how to tell when that point has arrived, and what to do about it.
How Do You Know Your Hot Water System Is Past Repair?
Age, the type of fault and the repair history decide it.
A relatively new unit with a failed element or thermostat is almost always worth repairing. The part is cheap and the system has years left. An older unit is a different story.
- •Water pooling around the base, which can indicate tank failure but can also come from the pressure relief valve, drain valve, loose fittings or condensation, so the source needs to be diagnosed
- •Rust-coloured water or visible sediment from the hot tap
- •Two or more repairs in the past two years
- •A unit older than eight to ten years that now has a fault
- •Hissing or popping from the unit
- •Hot water that runs out far sooner than it used to
A leaking tank cannot be repaired. Once the tank fails, replacement is the only option, so do not pay for a diagnostic hoping for a patch.
What Should You Do First When You Suspect Failure?
Three quick checks protect your home before the plumber arrives.
If water is pooling, turn the main shut-off valve clockwise to close it fully. That cuts supply to the whole house. Then switch the system off at the unit or breaker.
On an electric storage system, reset a tripped breaker once. If it trips again, stop and call a plumber. Never run an electric storage system dry, because that can burn out the element.
If you smell rotten eggs near a gas unit, leave the building and call a licensed gas fitter on 0408 012 993. Gas hot water repairs and leak fixes must be handled by a licensed gas fitter in WA. Our hot water systems page covers each system type.
What Does Replacing a Hot Water System Involve?
A replacement is a choice of system type, not a like-for-like swap.
Replacing a system means removing the old unit, connecting the new one to the existing water, power or gas supply, and testing it. Many people assume they must buy the same type again. You don’t.
A failure is a good moment to change technology, especially if the old unit gave you high energy bills. Gas units need a licensed gas fitter, and DIY gas work is not permitted in WA.
Our hub article, Perth Hot Water Systems Explained: Heat Pump, Solar, Gas or Electric?, covers the full detail. Below is my ranked shortlist for a typical Perth home replacing a failed unit.
Which Replacement Hot Water System Should You Choose?
Five options, ranked for a typical Perth home replacing a failed unit.
1. Heat pump, best for cutting electricity use
A heat pump uses electricity to move heat from the air into a tank. It needs no gas connection, so no gas fitter is involved. I install these, so weigh my opinion accordingly.
It earns first place on running cost direction, but loses to gas instantaneous on continuous supply. It also needs outdoor space for the unit. See our heat pump page, and our article on what a heat pump costs to run in Perth.
Best suited for: Homeowners replacing an inefficient electric storage unit who want lower power bills. It suits you if you have outdoor space and can accept a higher upfront cost than a basic electric tank.
2. Gas instantaneous, best for endless hot water without a tank
Instantaneous units heat water as it flows, so there is no tank to leak or run out. They suit larger households with back-to-back showers. They need a gas supply, and installation and repairs must be done by a licensed gas fitter.
Our article on gas storage versus gas instantaneous compares them directly.
Best suited for: Households already connected to gas that want continuous hot water. It is a poor fit if you have no gas supply.
3. Solar hot water, best for roof-equipped homes chasing lower energy use
Solar systems collect heat from the sun using roof collectors. They need suitable roof area, which rules out some homes. Our article on solar hot water in Perth covers whether it is worth it and which rebates are available.
Best suited for: Owners of homes with good roof exposure who plan to stay long term. If your roof is shaded, look at a heat pump instead.
4. Gas storage, best for homes with existing gas and simple demand
Gas storage units keep a tank of heated water ready. They need a licensed gas fitter and a tank that eventually corrodes like any other. Simple to replace like for like if the gas connection is already there.
Best suited for: Households with an existing gas connection that want a straightforward swap. Expect the stored volume to limit very heavy back-to-back use.
5. Electric storage, best for the simplest swap with no gas
Electric storage needs no gas and no gas fitter, which is a genuine advantage over options 2 and 4. The drawback is running cost, which is why people on high energy bills often move away from it. Our article on electric storage pros and cons covers when it still makes sense.
Best suited for: Renters, small households or properties with no gas supply that need the simplest replacement. Avoid it if high energy bills are your main complaint.
How Did I Rank These Replacement Options?
Rankings are earned on checkable facts, not preference. I only used criteria that are the same for every Perth home.
Fuel source
The energy the system runs on. It decides your ongoing bills and whether you need a gas connection.
Licensed gas fitter required
Yes or no. Gas work in WA must be done by a licensed gas fitter, which affects who you can hire.
Stores heated water
Yes or no. A tank can run out and can eventually leak.
Site needs
What the home must provide, such as outdoor space or roof area.
Side-by-Side Comparison
| Option | Best for | Fuel source | Licensed gas fitter required | Stores heated water | Site needs |
|---|---|---|---|---|---|
| 1. Heat pump | Homeowners replacing an inefficient electric storage unit who want lower power bills. | Electricity and air heat | No | Yes | Outdoor space |
| 2. Gas instantaneous | Households already connected to gas that want continuous hot water. | Gas | Yes | No | Gas supply |
| 3. Solar hot water | Owners of homes with good roof exposure who plan to stay long term. | Sun | No | Yes | Roof area |
| 4. Gas storage | Households with an existing gas connection that want a straightforward swap. | Gas | Yes | Yes | Gas supply |
| 5. Electric storage | Renters, small households or properties with no gas supply that need the simplest replacement. | Electricity | No | Yes | Tank space |
Which Replacement Fits Your Situation?
Match your situation to the option below, then call to confirm it suits your property.
| If you are… | Look for | Best fit |
|---|---|---|
| Your old electric storage tank leaked and your power bills were high | Lower electricity use and no gas connection | 1. Heat pump |
| You have gas and a large household with back-to-back showers | Continuous supply with no tank | 2. Gas instantaneous |
| You own a sunny, unshaded roof and plan to stay long term | Roof collectors and low energy use | 3. Solar hot water |
| You have gas already connected and want the simplest swap | Like-for-like gas replacement | 4. Gas storage |
| You have no gas and want the simplest, lowest-hassle replacement | No gas fitter and a tank-for-tank swap | 5. Electric storage |
Hot Water Replacement Questions
Straight answers to what Perth homeowners ask most.
How old is too old for a hot water system?
If a unit older than eight to ten years develops a fault, replacement is usually the better bet. Check the label on the unit for its age and tell the plumber when you call.
Can a leaking hot water tank be repaired?
No. Once the tank itself leaks, replacement is the only option. A leak from the pressure relief valve pipe is a different fault and can be assessed separately.
Can I fix a gas hot water fault myself?
No. DIY gas work is illegal in WA. Gas hot water repairs must be done by a licensed gas fitter, so call 0408 012 993.
How much will a replacement cost?
It depends on the system you choose. Plumb It Right uses fixed pricing with no callout fee, so you know the price before work starts.
Ready to Replace Your Hot Water System?
Call or text John on 0408 012 993 for a fixed price with no callout fee. Or send the details through the form and we will get back to you.
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Part of our guide: Perth Hot Water Systems Explained: Heat Pump, Solar, Gas or Electric?
John Nighingale
Professional Plumber · Plumb It Right
John Nightingale has 38+ years’ experience of working in the plumbing industry in Perth Western Australia and previously in the United Kingdom.
