Gas hot water

Requires gas supply—
Natural gas or LPG
Internal installations require a flue
Efficient - ratings up to 6.9 Stars
Quiet
External installations require
certain window, door and eave
clearances from the flue
Abundant energy resource
Natural Gas supply can provide
similar running costs to
Extended Off-Peak electricity.

Annual Energy Consumption and Star ratings

Gas Continuous Flow

Only heats when water flows through the unit
Rated by the delivery of a continuous stream of hot water. Flow rate is measured in litres per minute of water that the unit can deliver. This is based on an increase of 25oC above the incoming water temperature
An incorrectly sized system may struggle to heat the required amount of water
Require high volumes of gas (200 Mj/hr). Larger units may require even more. Gas pipe work may need to be re-sized in existing dwellings

Require 20mm cold water feed, maybe hard to retrofit into existing homes
Continuous flow water heaters will
deliver reduced flows compared to
mains pressure water heaters. There
is the possibility a customer may be disappointed with the flow rate from
a continuous flow water heater when compared to the flow rate of an existing mains pressure unit that the customer
is replacing
Standard continuous flow water heaters are set at 50o. This can be an issue at the kitchen and laundry where higher temperatures may be desired.
Models set to 60oC are also available.
Customers should be advised that a 50oC tempered line must run to all bathrooms however a separate untempered line (at 60oC) can be run to the kitchen & laundry
Are compact in size. Can be concealed subtly in a recess box to integrate with building design.
Suitable for internal or external installation, although internal units are rare.
Standard 10 year warranty on heat exchanger.
Most models also require 240V power source.
Some models are not suited to colder climates.
Gas continuous flow units may be coupled with solar applications.
No hot water if gas supply is disrupted.

Gas Storage

Cost effective to install in existing applications (12mm copper feed for cold/hot and gas connections, no requirement for 240V)
High efficiency, 10 years warranty models are available.
External installations require certain window, door and eave clearances from the flue
Unlike continuous flow units, gas storage units provide full mains pressure to multiple outlets