Start with the running cost, not the purchase price
Hot water is typically the second largest energy cost in an Australian home. The gap between the cheapest and most efficient option over a ten year life is usually far larger than the gap in purchase price.
That does not automatically mean buy the expensive one. It means the comparison should be over ten years, not over the quote.
Electric storage
Lowest purchase price, simple, reliable, and works anywhere there is power. It is also the most expensive to run of the four unless you are on a controlled off-peak tariff or have solar panels covering the daytime heating.
Best suited to smaller households, rentals where upfront cost governs, or homes with generous solar export where the tank can soak up the middle of the day.
Gas continuous flow
Endless hot water, compact, no standing heat loss because nothing is stored. Running cost sits in the middle, and it depends on your gas supply charge as much as your usage.
Best for households with variable demand and existing natural gas. Less compelling if you are on bottled LPG, where the fuel cost changes the maths considerably.
Heat pump
Moves heat rather than generating it, and typically uses around a third of the electricity of a resistive electric tank. Rebates are often available and change the payback significantly.
It needs ventilated outdoor space and it does make some noise, so placement matters. Worth checking the position before committing, which is something we look at on the quote visit.
Solar hot water
Lowest running cost of the four when the site suits it: good north facing roof space, unshaded, and a household that uses most of its hot water in the evening after a full day of sun.
Higher upfront cost and it still needs a booster for a run of overcast days. On the wrong roof it disappoints, which is why we would rather look at the roof than quote from a desk.
The short answer
There is not one. Tell us how many people are in the house, when everyone showers, what fuel is already connected and whether you have solar, and the right option is usually obvious within about five minutes of conversation.
Written by the team at Adlington Plumbing. Licensed plumbing and gas fitting across Newcastle, Lake Macquarie and the Central Coast. Licence 384065C.