Electric Hot Water Systems
Storage tanks and instantaneous electric units, plus element and thermostat repairs.
Learn more →What gas gets you in Mandurah
If your house is already on ATCO mains gas, a gas hot water system is usually the cheapest way to heat water day to day. The gas tariff in WA has historically sat well below the electricity rate per unit of useful heat, and a continuous flow unit only burns gas while a tap is open. That combination is hard for a plain electric storage tank to beat.
Two shapes exist, and they solve different problems.
Continuous flow (instantaneous)
A wall-mounted box with no tank. A burner ignites when water flows and modulates to hold a set temperature. Sizing is done in litres per minute — 16, 20, 26 and 32 L/min are the common Rinnai and Bosch ratings. A 16 handles a small unit or a one-bathroom house; a family of four with two bathrooms is usually a 20 or 26.
The advantages are real: no standing heat loss, no running out, and a small footprint, which matters on the narrow side setbacks common in newer Madora Bay and Lakelands lots. The trade-offs are that flow drops if two showers run simultaneously on an undersized unit, and that a power failure stops the unit — the electronics need mains power even though the heat is gas.
Gas storage
A cylinder with a burner underneath, holding 135 to 360 litres. It delivers full flow to several outlets at once and keeps working during a blackout if it has a standing pilot. Against that, it loses heat through the tank wall around the clock, and the cylinder itself has a finite life.
Installation in practice
Most Mandurah gas installations are external wall mounts on the side or rear of the house, within reach of the existing gas point. A straight replacement of a like unit in the same position is the cheapest job on the board. Costs climb when a new gas run is needed from the meter, when the unit moves, or when you are converting from electric — that conversion is priced in the hot water system cost guide.
Gas connection work in Western Australia must be carried out by a licensed gas fitter, and the plumbing side by a licensed plumbing contractor. A tempering valve is required so bathroom outlets deliver no more than 50°C. The installation page covers what happens on the day and what is included.
Where gas is the wrong answer
We will say so. If you are on bottled LPG and your usage is high, the running cost advantage largely evaporates and a heat pump is often the better long-term buy. If you have no gas at the property at all, the cost of bringing in a connection can exceed the difference in running costs for a decade. And if you already have a good north-facing roof, solar with gas boosting uses far less gas than a gas-only unit.
For a straight comparison of all four fuel types against household size, read the system selection guide, or call (08) 9516 1934 and tell us what is in your meter box.
More services
Explore our other services
Solar Hot Water Systems
Roof-mounted, split and evacuated tube solar with gas or electric boosting.
Learn more →Heat Pump Hot Water Systems
Air-source heat pumps suited to Mandurah's mild winters, standalone or retrofitted.
Learn more →Hot Water System Installation
Like-for-like swaps, relocations and fuel changeovers by licensed WA tradespeople.
Learn more →Hot Water Repairs
No hot water, leaking tanks, pilot light faults and tempering valve failures.
Learn more →
FAQs
Frequently asked questions
Is my Mandurah street connected to natural gas?
Most established Mandurah suburbs sit on the ATCO reticulated natural gas network, including Greenfields, Halls Head, Erskine and Meadow Springs. Coverage thins out in parts of Dawesville, Bouvard and the rural blocks east of the estuary, where bottled LPG is the norm. Check your meter box, or look for an existing gas cooktop or bayonet point, before pricing a gas system.
Continuous flow or gas storage — which is better?
Continuous flow suits households that use hot water in bursts across the day and never want to run out, and it wastes nothing keeping a tank warm. Gas storage suits homes with several showers running at once, or where the unit has to sit a long way from the bathrooms. Continuous flow units also need a minimum flow rate to fire, which can annoy anyone who likes a barely-open tap.
Can a gas hot water unit be installed inside?
Only with a proper flue. The default in Mandurah is an external wall-mounted unit, which avoids flue work entirely and keeps combustion air outside. Internal installations are possible but need clearances, a flue path and a licensed gas fitter's sign-off, and they add materially to the installed price.
How long does a gas hot water system last here?
A continuous flow unit typically gives ten to fifteen years, a gas storage tank around eight to twelve. Coastal streets pull that down: salt attacks the casing, the burner tray and the flue terminal. A unit on a Halls Head or Silver Sands wall that gets rinsed with fresh water occasionally will outlast one that never does.
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