When your hot water system fails, one of the first questions on your mind is how much a replacement will cost. The answer depends on several factors including the type of system you choose, whether you are switching from one fuel type to another, and the complexity of the installation at your Rockingham property. This guide breaks down realistic costs so you can budget accordingly and avoid any surprises.
Average Replacement Costs by System Type
Hot water system replacement costs in Rockingham vary significantly depending on the technology you select. Here is a realistic breakdown of what you can expect to pay in 2026, including supply and standard installation.
Gas Storage Hot Water Systems
A gas storage system is often the most affordable option for a straightforward like-for-like replacement. For a standard 135 to 170-litre unit suitable for two to four people, expect to pay between $1,200 and $2,000 fully installed. Larger 250 to 360-litre units for bigger households typically range from $1,800 to $2,800 installed. These prices assume your existing gas line and fittings are in good condition and the new unit is being installed in the same location.
Continuous Flow Gas Systems
Continuous flow or tankless gas hot water systems cost more upfront but offer long-term savings through lower running costs. A quality continuous flow unit installed in Rockingham typically costs between $1,800 and $3,200. The variation depends on the flow rate capacity you need. A 20-litre-per-minute unit is suitable for most standard homes, while a 26-litre-per-minute model is better for larger homes with multiple bathrooms.
Electric Storage Systems
Electric storage hot water systems have the lowest upfront cost, ranging from $900 to $1,800 fully installed for a standard 125 to 250-litre unit. However, bear in mind that running costs are significantly higher than gas or heat pump alternatives, which means you will pay more over the system’s lifetime.
Heat Pump Systems
Heat pump hot water systems carry the highest upfront price tag, typically $3,000 to $5,500 installed before any rebates. The good news is that government incentives through Small-scale Technology Certificates and state rebates can reduce the effective cost to $1,500 to $3,000 in many cases. Given that running costs are 60 to 75 percent lower than electric storage, the payback period is usually three to five years.
What Factors Affect the Final Price?
Several factors can push your replacement cost higher or lower than the average ranges listed above.
Like-for-like replacement versus system changeover. Replacing an old gas storage unit with a new gas storage unit is the simplest and cheapest scenario. Switching from electric to gas or from gas storage to continuous flow requires additional pipework, fittings, or electrical modifications that add $300 to $1,000 to the total cost.
Location of the unit. If your hot water system is in a straightforward location with easy access, installation is faster and cheaper. Units located in tight spaces, on upper floors, or requiring long pipe runs to the bathroom and kitchen will cost more to install due to additional labour and materials.
Condition of existing infrastructure. Old or corroded gas lines, outdated pressure relief valves, and non-compliant tempering valves may need to be upgraded to meet current Australian Standards. This is not optional, as your plumber is legally required to ensure the installation meets WA plumbing regulations. Budget an additional $150 to $500 for any compliance upgrades.
Disposal of the old unit. Most plumbers include removal and disposal of the old system in their quote, but it is worth confirming this upfront. Disposal fees typically range from $50 to $150 if charged separately.
Emergency versus planned replacement. If your hot water system fails unexpectedly and you need a same-day replacement, you may pay a premium for urgent call-out fees and limited choice of available units. Planning your replacement before the old system completely fails gives you time to compare quotes and choose the best system for your needs.
Government Rebates and Incentives
Australian homeowners upgrading to energy-efficient hot water systems may be eligible for financial incentives that significantly reduce the upfront cost.
Small-scale Technology Certificates (STCs): Heat pump and solar hot water systems qualify for STCs under the federal government’s renewable energy target. The value of STCs fluctuates but typically reduces the purchase price by $700 to $1,000. Most suppliers factor this discount into their quoted price.
State and Local Rebates: Western Australia occasionally offers additional rebates for energy-efficient appliances. Check with your local council or the WA Department of Energy for current programs that may apply to Rockingham residents.
Energy Retailer Incentives: Some gas and electricity retailers offer cashback or discounts when you upgrade to an efficient hot water system. It is worth checking with your energy provider before committing to a purchase.
How to Get the Best Price
To ensure you get a fair price for your hot water system replacement in Rockingham, follow these practical steps.
Get at least two to three written quotes from licensed plumbers. Make sure each quote specifies the brand and model, installation inclusions, and any exclusions. Be wary of quotes that seem unusually low, as they may not include necessary compliance upgrades or quality materials.
Ask about warranty coverage for both the unit and the installation workmanship. A reputable plumber will offer at least a one-year warranty on their labour in addition to the manufacturer’s product warranty, which is typically five to ten years on the tank and one to two years on parts.
Consider the total cost of ownership over 10 to 15 years rather than just the upfront price. A heat pump system that costs $3,500 today but saves $400 per year in running costs will be cheaper over its lifetime than a $1,500 electric storage unit with high ongoing energy bills.
When Should You Replace Rather Than Repair?
As a general rule, if your hot water system is more than 10 years old and requires a repair costing more than $500, replacement is usually the more economical choice. Systems approaching the end of their expected lifespan are more likely to develop additional faults, and parts for older models may be difficult to source.
If you are noticing signs your hot water system needs replacing, do not wait for a complete failure. A planned replacement gives you time to choose the best system and schedule installation at a convenient time.
Get an Accurate Quote for Your Home
Every Rockingham property is different, and the best way to get an accurate replacement cost is to have a licensed plumber inspect your current setup. Plumber Rockingham provides free, no-obligation quotes for hot water system replacement across Rockingham, Baldivis, Port Kennedy, Secret Harbour, and surrounding areas. Contact us today to find out exactly what your replacement will cost and which system is the best fit for your home and budget.
