Complete domestic and commercial hot water solutions — DHW tanks, buffer tanks, thermal stores and heat-pump hot water. AHHAC supplies the Latento WP-S stratified tank, Nexus tanks and the MAXA hot water heat pump range.
DHW cylinders and buffer tanks for hydronic systems do two different jobs: a DHW cylinder stores drinking-quality hot water for taps and showers, while a buffer tank holds heating water so the heat pump runs long, steady cycles instead of short-cycling. AHHAC supplies and installs the Latento WP-S stratified thermal store, Nexus 200–315 L single and twin-coil DHW cylinders and Nexus 100–200 L buffer tanks, paired with MAXA heat pumps that make hot water up to 78 °C.
Reviewed by the AHHAC Technical Team — licensed plumbers & hydronic engineers, NSW Lic 262528C.How we write & review
Hot water is where domestic and commercial hydronics meet. Whether it's a family of five or a 200-room hotel, the principles are the same: generate heat efficiently (heat pump, boiler or solar), store it intelligently (a well-stratified tank or thermal store), and deliver it on demand without running out.
AHHAC supplies a complete hot water package — the Latento WP-S stratified thermal store (which layers hot water at the top and cool at the bottom for maximum usable capacity), the Nexus DHW and buffer tank range (100 L, 200 L, single and twin-coil 315 L), and MAXA hot water heat pumps for the heat source. For larger commercial demand, see our dedicated MAXA HWA2 commercial range.
Domestic: a single DHW cylinder or thermal store (200-315 L) heated by a heat pump or boiler covers most homes. A twin-coil tank lets two heat sources (e.g. solar + heat pump) feed the same store. Commercial: cascaded heat pumps feeding multiple large stores, sized to peak simultaneous demand with redundancy. AHHAC sizes the storage to your draw profile and the heat source to your recovery requirement. For full commercial plant, see the MAXA HWA2 reversible chillers and heat pumps.
Stratified thermal store that layers hot water at the top and cool at the bottom — maximises usable hot water from a heat pump and smooths demand peaks. Ideal for heat-pump DHW.
Twin-coil cylinder lets two heat sources (solar + heat pump, or boiler + heat pump) feed one store. Also available single-coil.
Buffer tanks decouple the heat pump from the distribution system — reducing short-cycling and extending compressor life.
R290 monoblock delivering domestic hot water up to 78°C. Pairs with the Latento or Nexus stores for an all-electric DHW solution.
Storage is where a good heat pump system is often let down. The heat pump gets all the attention, then it is connected to a cylinder with a coil sized for a gas boiler, or straight onto a network of small zones with no buffer at all. Here is how we decide what goes in.
Where two heat sources share a store, the twin-coil 315 L cylinder lets solar feed the lower coil while the heat pump or boiler tops up the upper one. The connections matter: piping a return into the wrong port mixes the layers and wastes the stratification you paid for.
We also plan for hygiene and convenience. A heat pump such as the Maxa i-290 can lift stored water to 78 °C, so a periodic high-temperature cycle for legionella control does not have to rely on an electric element. And we place the cylinder as close to the main bathrooms as the plant layout allows, because long pipe runs mean waiting for hot water and losing heat along the way.
For solar-fed stores, see solar hydronic heating. For hotel, aged-care and apartment-scale plant, our commercial hot water heat pumps page covers the MAXA HWA2 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.
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.
"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."