HJ Cooper Stainless Steel Mains Pressure Hot Water Cylinder 180L - 550x1295 3kW

Product code: MS18055030



Please note: For off shore island or international purchases you will need to create a 'Quote List' or simply contact any store and our friendly team will assist you.

HJ Cooper by Rinnai stainless steel mains pressure hot water cylinders are constructed from high grade duplex stainless steel and packed with features to benefit specifiers, installers and homeowners, making them exceptional value for money.

  • MS18055030 = 180 L (3 kW) 550x1295

Peace of mind

This range of mains pressure electric hot water cylinders comes with a 20 year limited warranty on the inner cylinder*. You won't find a longer warranty on any other electric hot water cylinder in New Zealand! Whats more, it's backed by Rinnai after sales support.

  • Energy efficient
  • Curved element design ensures 98% of water is heated.
  • Cold water inlet dip tubes deliver water to the bottom of the tank to avoid mixing of water
  • No cylinder wraps required, all HJ Cooper cylinders meet NZ MEPS

MEPS = Minimum Energy Performance Standard

Future proof your home

Connect to a hot water heat pump or solar system with the extra eco inlet connection**, either now or in the future. Install as a low pressure system then connect, without replacing your cylinder, to the luxury of mains pressure when you are ready.


  • Lightweight, stainless steel makes transport and installation are a breeze
  • Low maintenance, no sacrificial anode to maintain
  • Future proofed, auto reset thermostat option means these cylinders can be solar and hot water heat pump ready

Innovative design

The 250 and 300 L cylinders have the option of a second element making recovery times quicker and making it less likely you'll run out of hot water.

* Please see the owner and installer guide, in the 'Specifications' tab, for full warranty details

** Excludes 135 L cylinder

OTHER Models and capacities available

  • MS13555020 = 135 L (2 kW)
  • MS13555030 = 135 L (3 kW)
  • MS18055020 = 180 L (2 kW)
  • MS25055020 = 250 L (2 kW)
  • MS25055030 = 250 L (3 kW)
  • MS30055020 = 300 L (2 kW)
  • MS30055030 = 300 L (3 kW)

Within the range there are different element sizes and configurations, and thermostat options.

  A(mm) B(mm) C(mm) D(mm) E(mm) Height (mm)

Diam (mm)

135L 310 NA 325 NA 690 1023 ø 550
180L 310 460 325 NA 970 1295 ø 550
250L 310 460 325 1080 1410 1730 ø 550
300L 310 460 325 1380 1725 2047 ø 550

Suitable for

  • Indoor installations
  • Mains and low pressure systems
  • Domestic and commercial water heating applications
  • Left or right hand plumbing connections
  • Connection to open loop solar or hot water heat pump systems

Not suitable as a pool or spa heater.

Water quality

HJ Cooper water heaters are manufactured to suit most New Zealand council water supplies. However some water supplies can have a detrimental effect on the water heater, its operation and life expectancy. Water supplies with a high level of calcium carbonate (hard water) can cause scaling on hot surfaces. We recommend a water temperature of no more than 65

Installation Guide Download
Pocket Guide Download
Retrofit Installation Download
Spares Download
Supplier Declaration Download