Hot water systems in Sydney come in five main types: electric storage, gas storage, gas continuous-flow, solar thermal and heat pump. The right one depends on household size, available fuel, roof space and how long you will stay in the home. AHHAC supplies and installs every type as an authorised Rheem and Rinnai supplier, with same-day replacement in most metro areas and stock held at all six showrooms across NSW, VIC, QLD and the ACT.
Reviewed by the AHHAC Technical Team — licensed plumbers & hydronic engineers, NSW Lic 262528C.How we write & review
Cheapest install, highest run cost. Best for holiday homes & solar PV households.
Mature, fast-recovery, lower run cost. Most common Australian choice.
Heat on demand, never run out, smaller footprint, 20+ year unit life.
Greenest options. 80–90% energy reduction. STC rebates apply.
Best paired with existing geothermal heating. COP 4.5–5.5.
Australian-made since 1939. Full range supplied through all six showrooms.
Industry-leading 12-year warranty. Continuous-flow specialists.
Six questions that determine the right system for your home.
Most hot water systems in Sydney are replaced in a hurry, on the morning the shower runs cold. A few warning signs give you time to choose a system instead of taking whatever is on the shelf.
Take a photo of the data plate on your current unit. The manufacture date, capacity and fuel type let us tell you over the phone whether a repair is worth it, and let us quote both a like-for-like swap and an upgrade. Replacing an old electric tank with a heat pump or solar system often makes most sense at this point, because the plumbing is already being opened up.
On the day, we isolate the water and the power or gas, drain and remove the old unit, and set the new one on a compliant base or bracket with the right clearances. Every install is brought up to current rules, not the rules that applied when the old tank went in. Stored water is heated to at least 60 °C to control Legionella, and AS/NZS 3500 requires hot water to be delivered to bathrooms at no more than 50 °C, so a tempering valve is fitted if one is missing. New isolation valves, a pressure-limiting valve where mains pressure is high, and a drain line for the relief valve finish the job. You receive a compliance certificate, we register the warranty, and the old unit leaves with us for disposal.
For capacities and tank linings, see our hot water tanks range. To compare running costs first, read the guide to selecting the best hot water system, or go straight to hot water heat pumps and solar hot water systems, where STCs and other rebates may apply and we check eligibility for you.
Written from on-site experience by the AHHAC Technical Team.
AHHAC's in-house design and service team — licensed plumbers and hydronic engineers (Lic 262528C) who have designed and installed 2,400+ hydronic heating, cooling and hot water systems across Australia since 1998.
Every plumbing and hot water job is assessed on site, carried out by our own licensed plumbers and gasfitters to AS/NZS 3500 (plumbing) and AS/NZS 5601 (gas), pressure-tested and documented, and backed by ongoing service. Nothing is subcontracted out.
Three big factors: household size, available fuel, and how long you'll live in the home. Heat pumps and solar systems pay back fastest if you're staying 5+ years; gas continuous-flow is the safe default for most Australian households; electric storage only if you have nothing else and a tight budget.
Yes — same-day in most metro areas (Sydney, Melbourne, Canberra, Gold Coast/Brisbane). We carry full Rheem and Rinnai stock at all six showrooms, plus Viessmann DHW heat pumps. Compliance certificates and old unit disposal included.
Yes — registered solar and heat pump water heaters earn Small-scale Technology Certificates (STCs). The value depends on the model, your postcode and the year (it declines each year to 2030), and state programs sometimes add more. We confirm current amounts at quote and handle the paperwork.