How the main options differ
The right system depends on the property, household size, available space, energy connections, local climate and how the household uses hot water. No single option will suit every property.
Gas storage
A gas storage system uses a burner to heat water held in a tank. Heat is lost while the water remains stored, and the property needs an ongoing gas supply.
For buyers considering a fully electric home, an existing gas system may become part of a future replacement plan.
Gas continuous flow
A gas continuous flow system heats water as it is needed rather than storing it in a tank. This reduces storage heat loss, although the system still relies on gas supply and suitable installation.
Continuous flow does not necessarily mean hot water reaches the tap immediately. Delivery time still depends on the distance between the system and the outlet.
Electric resistance storage
An electric resistance system uses an electric element to heat water stored in a tank. These systems are generally inexpensive to purchase, although they usually use considerably more electricity than a heat pump.
Some systems can operate on a controlled load or be timed to use electricity during suitable tariff or rooftop solar periods.
Heat pump water heater
A heat pump transfers heat from the surrounding air into the water. Australian Government guidance indicates that a heat pump can use about 30 per cent of the energy required by a conventional electric hot water system.
Heat pumps require suitable space and ventilation. Some units produce noticeable operating noise, so their position relative to bedrooms, outdoor areas and neighbouring properties should be considered.
Performance, noise, controls and suitability vary between models.
Solar hot water
A solar hot water system uses roof mounted collectors to heat water directly. These collectors are different from solar photovoltaic panels, which generate electricity.
An electric or gas booster may be required when there is insufficient solar energy. Buyers should consider collector condition, roof space, orientation, shading, booster type and maintenance history.
Heat pump and solar hot water systems can reduce purchased energy use compared with conventional electric resistance systems. Actual running costs and savings depend on the system, household usage, tariffs, climate, installation and any rooftop solar generation.
Understand the existing system
A few practical checks can help identify whether the current system suits the property and whether replacement should be allowed for.
System type
Identify whether the system uses gas, electric resistance, a heat pump or solar hot water.
Approximate age
Check the manufacturing or installation date where available. Service life varies between systems and depends on installation, use, water quality and maintenance.
Visible condition
Look for corrosion, leaking water, damaged pipework, staining or other signs that further assessment may be worthwhile.
Capacity
Confirm whether the tank size or continuous flow capacity is suitable for the likely number of occupants.
Energy supply
Check whether the system relies on electricity, natural gas, liquefied petroleum gas or solar energy with a booster.
Location and noise
Consider access for servicing, ventilation and the potential effect of operating noise, particularly for heat pumps.
Controls and tariff
Check whether the system uses a controlled load, timer or other setting that affects when it operates.
Documentation
Ask whether installation records, warranties, servicing information or recent invoices are available.
Consider the property as a whole
If replacement is likely, the appropriate option depends on more than the price of the unit. Installation space, plumbing changes, electrical capacity, gas disconnection, household demand and available rooftop solar may all affect the work required.
An appropriately licensed tradesperson can assess the property and recommend a suitable system. An electrician may also need to confirm switchboard capacity, circuit requirements and any changes needed for a new electric system.
Replacing a working system early will not suit every household. For many owners, the most practical time to reconsider the technology is when substantial repairs or replacement become necessary.
Solar and eligible heat pump hot water systems may qualify for Small-scale Technology Certificates. Other government assistance can change over time, so eligibility and current programs should be checked before relying on a rebate or discount.
Hot water in Noosa homes
Noosa's generally warm climate can suit heat pump and solar hot water systems, although product selection, installation and site conditions still matter.
Homes with rooftop solar may be able to schedule an electric hot water system to operate during periods of solar generation. The benefit depends on the system controls, household usage, electricity tariff and amount of surplus solar energy available.
Gas and electric resistance systems remain present in many established properties. Buyers planning future electrification should identify how the hot water system connects with the rest of the home and what work may be required when replacement becomes necessary.
For a broader look at household energy use, electrification and sustainable property features, explore the related NPS guides below.