Rinnai HydraHeat 340L

The Rinnai HydraHeat 340L is the larger tank size in the same integrated heat pump water heater range as the 275 L unit: a removable head unit manufactured in New Zealand sits on top of a mains-pressure enamel storage cylinder manufactured in China. It uses only 150 g of R290 refrigerant and has no electric backup element in Standard mode; it is factory preset to continually heat water to 60 degrees C, with a 4.7 COP at 19 degrees C ambient (water heated 19 to 55 degrees C) and a 45 dB(A) operating noise level. The system is designed to operate efficiently across -10 to 42 degrees C ambient (the electric element, used only for Boost/High Usage/Element Only modes, keeps the system running down to -10 degrees C and up to 45 degrees C at reduced efficiency).

This is a genuinely New Zealand-specific product line, distinct from the “Enviroflo” and “Hotflo Plus” ranges Rinnai sells in Australia - there is no shared model naming between the two markets. The cylinder can be purchased on its own, with the heat pump head unit added later (“heat pump ready” design). Other modes: Boost (one-off 70 degrees C), Eco 50/55 (continuous 50/55 degrees C), High Usage (continuous 70 degrees C, heat pump plus element), Element Only (70 degrees C, element only, used if the heat pump faults), and Shutdown.

Tested and certified to AS/NZS 5125, AS/NZS 60335.1/60335.2.40, AS/NZS 4692.1 (cylinder), AS/NZS 4020, AS/NZS CISPR 14.1, AS/NZS 2712, and AS/NZS 4234:2021. Rinnai NZ backs the product for 5 years with 1 year labour, recommends a service every two years, and the cylinder anode should be replaced every 5 years or more frequently in hard-water areas.