Japanese-engineered continuous-flow hot water with industry-leading 12-year warranties. AHHAC is an authorised Rinnai installer.
Rinnai hot water systems in Sydney are best known for the Infinity continuous-flow range, sized at 16, 20, 26 or 32 litres per minute and backed by a 12-year heat exchanger warranty. AHHAC is an authorised Rinnai installer across Sydney, Melbourne and Brisbane, fitting Infinity, Builders' Edition and Demand Duo systems, setting up MyRinnai app control on Wi-Fi models, and stocking Rinnai units at all six showrooms for same-day metro replacement.
Reviewed by the AHHAC Technical Team — licensed plumbers & hydronic engineers, NSW Lic 262528C.How we write & review
Rinnai pioneered continuous-flow gas hot water and remains the category leader. Their Infinity range is rated for 6+ outlets simultaneously with stable temperature control.
We install the full Rinnai range including Infinity, Builders' Edition, and the Demand Duo storage-and-continuous-flow hybrid.
Most Rinnai hot water systems we fit in Sydney are Infinity continuous-flow units, and the number in the model name is the decision that matters most. It is the peak flow in litres per minute the unit can deliver at a typical temperature rise, so it should match how many hot outlets run at once in your home.
If a household sits between two sizes, we generally size up. The difference in purchase price is small next to living with a unit that drops temperature when the dishwasher starts mid-shower.
Servicing is what gets an Infinity to the 20-plus years these units are capable of. A periodic service cleans the water inlet filter, checks combustion and the fan, and inspects the heat exchanger. In harder water areas, scale builds up inside the heat exchanger over time, and a descale restores flow and efficiency. A service history also supports any claim under the 12-year heat exchanger warranty, which we register at install.
If your unit stops, look at the controller before you call. Rinnai units display an error code, and telling us the number lets us bring the likely part and often fix it on the first visit. Wi-Fi models with the MyRinnai app show the code on your phone as well.
For how continuous-flow behaves day to day, from pipe runs to temperature controllers, see our instantaneous hot water systems guide. For gas supply and flue requirements, read gas hot water systems, or compare the Rheem hot water range.
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.
Japanese engineering quality, 12-year heat exchanger warranty (industry-leading), reliable temperature control even with multiple draws, smartphone integration via MyRinnai app, available with optional pre-heat for instant hot water. They simply work for 20+ years.
Infinity range covers most homes — sized 16, 20, 26 or 32 (litres-per-minute peak flow). Larger Demand Duo combines storage + continuous-flow for very high demand. We'll size based on number of bathrooms and simultaneous use scenarios.
Yes — MyRinnai app integrates with Wi-Fi-equipped models. View energy use, set scheduled temperature changes, get error alerts. Compatible with Google Home and Amazon Alexa.
"AHHAC delivered our 22-zone underfloor system on time, on budget and to spec. The crew were tidy, the documentation was thorough, and the commissioning was textbook."
"We've worked with AHHAC for 17 years. They've installed and serviced our hot water plant across three commercial buildings — and they pick up the phone on weekends."
"Three mobs quoted us; AHHAC's design was the only one based on a proper heat-loss calculation. The system runs beautifully — the others would've been oversized and expensive."