Gas Hot Water Systems from $869

Continuous Flow vs Gas Storage

The first decision is whether the property needs continuous-flow gas or gas storage. Replacing like-for-like is often the simplest path because the plumbing, gas supply, location and system behaviour are already suited to that technology.

Instant Gas Hot Water Systems

Continuous-flow gas water heaters do not keep a large tank of water hot. When a hot tap opens and the required minimum flow is reached, the burner starts and heats water as it passes through the heat exchanger. This creates a compact system that can continue producing hot water while the unit remains within its flow and heating capacity.

These systems are commonly compared by nominal flow rate, such as 16L/min, 20L/min or 26L/min classes. The advertised flow is not the amount of hot water guaranteed at every temperature. Delivered flow depends on incoming water temperature, selected outlet temperature and how much temperature rise the heater needs to provide.

135L, 170L & High-Recovery Gas Storage

Gas-storage systems keep a tank of hot water ready for use and use a gas burner to recover the cylinder as hot water is drawn. Because the burner can replace heat relatively quickly, a gas-storage system can deliver substantially more hot water over an hour than its nominal tank litres alone suggest.

This is why first-hour delivery and recovery rate are useful when comparing gas storage. Current HWO listings include common 135L and 170L systems, as well as high-recovery premium gas-storage products such as the Rheem Stellar 330.

Natural Gas vs LPG Hot Water Systems

Natural Gas and LPG systems are not interchangeable simply because the appliances look the same. Burner configuration, injectors, gas pressures and certification are matched to the intended fuel. Choose the product variant designed for the property’s existing gas supply.

Natural Gas is normally supplied through a mains network. LPG is typically supplied from cylinders or a site storage arrangement. If the existing appliance label is unclear, confirm the fuel before ordering.

How Do I Size a Gas Hot Water System?

Continuous-flow and storage gas systems are sized differently. Continuous flow is primarily about peak simultaneous flow and temperature rise. Storage is about the combination of tank capacity, burner recovery and how the household uses hot water across the day.

Gas Star Ratings & Running Efficiency

Gas water heaters use energy-rating labels and model efficiency information to help compare gas consumption. Within a comparable product type, a higher star rating generally indicates better gas efficiency. Continuous-flow systems can avoid the standing heat losses associated with keeping a storage tank hot, while modern storage systems can combine insulation with efficient burner design.

Running cost still depends on household hot-water demand, local gas pricing, climate, gas type and system operation. A high star rating does not tell you whether the flow rate or storage capacity is right for the household.

50°C Preset, Higher-Temperature Models & Gas Controllers

Continuous-flow gas systems can be sold with different maximum temperature settings depending on model and application. Some domestic models are factory limited to 50°C, while other versions can provide higher set temperatures and may require suitable temperature control elsewhere in the plumbing installation.

Selected continuous-flow ranges support optional wired or wireless controllers for more convenient temperature selection. Controller compatibility, maximum set temperature and the number of supported controllers vary by brand and model.

Do Gas Hot Water Systems Need Electricity?

Many modern continuous-flow gas water heaters use electricity for electronic ignition, fan operation, controls or anti-frost protection. That means the gas supply alone may not be enough for the appliance to operate during a power outage.

Gas-storage systems can use different ignition and control arrangements depending on the model. Some traditional systems operate without a mains power point, while others use electrical components. Always check the exact product specification rather than assuming all gas water heaters are independent of electricity.

Gas vs Electric Storage vs Heat Pump Hot Water

Replacing an Existing Gas Hot Water System

Like-for-like replacement is often the simplest gas pathway, but model details still matter. A new continuous-flow unit may use a different gas connection, water connection, electrical requirement or physical footprint. Gas-storage systems can differ in tank height, diameter, valve settings and gas input.

What Needs to Match Before Ordering?

Gas connection size and available gas supply need to support the selected appliance. Higher-output continuous-flow units can require substantial gas input, so an existing gas line should not be assumed adequate simply because another gas water heater is already installed.

Water pressure, hot and cold connection positions and valve requirements also vary. Gas-storage systems use pressure and temperature relief valves and may require pressure-control or expansion-control components matched to the exact cylinder. Continuous-flow systems use a different connection and temperature-control arrangement.

Product price only. Delivery, valves, fittings, pipework, installation, gas fitting, electrical work, disposal and compliance work are separate unless expressly included with the selected product.

Gas Hot Water Warranty & Service

Gas-water-heater warranty structures vary between product types. Storage systems may have long cylinder warranties with shorter coverage for burners, controls, valves and labour. Continuous-flow warranties can separate the heat exchanger from other components and labour.

Keep the full model and serial number for service and replacement parts. Gas appliances should be serviced and repaired by appropriately licensed trades, and the exact manufacturer maintenance requirements should be followed.

Common Gas Hot Water Problems

A gas hot water fault does not automatically mean the complete unit needs replacement. Ignition, gas supply, water flow, power, controllers, thermostats, sensors, burners, valves and plumbing can all cause loss of hot water or poor performance.

Buying a Gas Hot Water System Supply Only

Choose the gas system first, then check delivery and add only the valves, pipework, fittings or accessories required for the job. For a replacement, record the existing brand, model, Natural Gas or LPG type, flow rate or storage capacity, dimensions, connections and installation location before selecting the new system.