Storage tanks from 50L (point-of-use) to 1,000L+ (commercial). Stainless steel, vitreous-enamel-lined, glass-lined — every type for every application.
Hot water tanks store heated water for taps and showers, while buffer tanks store heating water to smooth the output of a heat pump or boiler; both range from 50 L to over 1,000 L. Allow about 50 L of hot water storage per person, so a four-person home needs 200 L or more. AHHAC supplies and installs vitreous-enamel, stainless and glass-lined tanks, buffer tanks and thermal stores, with tank warranties typically of 5–12 years.
Reviewed by the AHHAC Technical Team — licensed plumbers & hydronic engineers, NSW Lic 262528C.How we write & review
Tank choice affects warranty period (typically 5–12 years), heat loss, water quality, and total system cost. We supply Rheem, Rinnai, Aquamax, Sanden, Apricus, Stiebel Eltron and Wiseliving.
For hydronic systems we often spec a thermal store — a large insulated tank that buffers heat from multiple sources (boiler, solar, heat pump) and delivers it to both heating and hot water on demand.
Premium insulated thermal store designed for hydronic + hot water buffering. Stainless construction, 10+ year warranty.
A storage tank is one of the simplest parts of a hot water or hydronic system, which is exactly why it gets ignored until it leaks. Most of the early failures we replace come down to a handful of avoidable things.
They look similar but do different jobs. A hot water tank stores drinking-quality water for taps and showers. A buffer tank holds the heating water itself, giving a heat pump or boiler enough volume to run long, efficient cycles instead of short-cycling. Some homes need both, and a thermal store can combine the two. Size the hot water tank to the household and the buffer to the heat source.
For help choosing the heater itself, see selecting the best hot water system. Our DHW cylinders and buffer tanks for hydronic page covers twin-coil and stratified stores, and if your water is hard, water filtration helps protect the tank as well.
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.
We only specify equipment after a heat-loss and system-compatibility check, then supply, install and commission it with our own licensed plumbers to AS/NZS 3500 (plumbing) and AS/NZS 5601 (gas), register the manufacturer warranty and service it for the life of the system.
Storage tanks: 50L per person is the rule of thumb. So a 4-person household needs 200L+; add buffer for spas/bathtubs/large shower heads. Thermal stores (for hydronic): sized to buffer your boiler/heat pump output, typically 200–500L.
Vitreous-enamel: cheapest, 5–10 year warranty, fine for most homes. Stainless: more expensive, 10–25 year warranty, better for hard-water areas. We test your water and recommend.
A large insulated tank that buffers heat from multiple sources (boiler, solar, heat pump, wood burner) and delivers it to both heating and hot water on demand. Essential for solar thermal and biomass systems; useful for grid-tied heat pumps too.
"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."