Stainless Steel Low-Medium Pressure Indoor Cylinders


These premium low pressure hot water cylinders are an ideal replacement option

Constructed from high grade duplex stainless steel and packed with features to benefit specifiers, installers and homeowners, making them exceptional value for money.

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

With the 180 L or 250 L, connect to a hot water heat pump or solar system with the extra eco inlet connection now or in the future. The 250 L cylinder also has the option of a second element making recovery times quicker and making it less likely you'll run out of water.


Read More

Product Details

Suitable for:

  • indoor installations only
  • indoor low-medium pressure systems
  • residential 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
Rinnai cylinders are manufactured to suit most NZ council water supplies. However some supplies can have a detrimental effect on the cylinder, its operation and life expectancy.  Stainless steel cylinders are not suitable for bore or tank water.

Water supplies with a high level of calcium carbonate (hard water) can cause scaling on hot surfaces. We recommend a temperature of no more than 65 °C to minimise scale buildup. Scale reducing or water softening devices should be considered in hard water areas.  The unit is not guaranteed against damage due to scaling.

Technical Specifications


550 mm

IP rating



10 years


Not required


Hot and cold water connections ¾ " (20 mm)


Inner cylinder: High grade duplex stainless steel
Outer casing: Galvanised steel


Incoloy 825 alloy sheath element positioned at the bottom of the tank.

Operating pressures

Maximum inlet pressure = 120 kPa
Maximum working pressure = 120 kPa

Thermal insulation

CFC-free polyurethane foam, compliant with MEPS standard


Robert Shaw 30 A contact thermostat, manually resettable at 85 °C. Thermostat can be upgraded to an auto-reset thermostat for solar and hot water heat pump applications.

Model Weight empty Weight full
135 L 26.5 kg 161.5 kg
180 L 31.5 kg 211.5 kg
250 L 41 kg 291 kg
Cylinder recovery times (theoretical)

Based on a thermostat temp. setting of 60 °C and an incoming water temp. of 15 °C.

  • 135 L = 3 hrs 56 mins (2 kW), 2 hrs 37 mins (3 kW)
  • 180 L = 5 hrs 15 mins (2 kW), 3 hrs 30 mins (3 kW)
  • 250 L = 7 hrs 17 mins (2 kW), 4 hrs 51 mins (3 kW)
  • 250 L = 3 hrs 39 mins (2 x 2 kW), 2 hrs 25 mins (2 x 3 kW)

No cylinder wrap required. All Rinnai cylinders meet the NZ Minimum Energy Performance Standard (MEPS).

Order codes - standard lower element
  • LS13555020 135 L 2 kW (height 1020 mm)
  • LS13555030 135 L 3 kW (height 1020 mm)
  • LS18055020 180 L 2 KW (height 1295 mm)
  • LS18055030 180 L 3 kW (height 1295 mm)
  • LS25055020 250 L 2 kW (height 1740 mm)
  • LS25055030 250 L 3 kW (height 1740 mm)
Order codes - standard dual element
  • LS250550D20 250 L 2 x 2 kW (height 1740 mm)
  • LS250550D30 250 L 2 x 3 kW (height 1740 mm)
Order codes - standard upper element
  • LS250550U20 250 L 2 kW (height 1740 mm)
  • LS250550U30 250 L 3 kW (height 1740 mm)
Order codes solar lower element (ART thermostat)
  • LS18055020A 180 L 2 kW (height 1295 mm)
  • LS18055030A 180 L 3 kW (height 1295 mm)
  • LS25055020A 250 L 2 kW (height 1740 mm)
  • LS25055030A 250 L 3 kW (height 1740 mm)
Order codes solar dual element (ART thermostat)
  • LS250550D20A 250 L 2 x 2 kW (height 1740 mm)
  • LS250550D30A 250 L 2 x 3 kW (height 1740 mm)
Order codes solar upper element (ART thermostat)
  • LS250550U20A 250 L 2 kW (height 1740 mm)
  • LS250550U30A 250 L 3 kW (height 1740 mm)


In all Rinnai cylinder instructions, we mandate the use of a drip tray. This is because all cylinders have the potential to leak water and cause extensive damage.

Our instructions state: The Rinnai warranty does not cover any consequential loss from leaks to the cylinder, so it’s important a suitably drained drip tray/catch pan is fitted as per AS/NZ 3500.4:2015 5.4 and G12/AS1 6.11.3. Like-for-like replacements are a grey area as most installers will only replace the cylinder to the same configuration as the cylinder that is being replaced. In these instances, Rinnai still maintains that a drip tray should be fitted. This protects the homeowner and the building from any future problems should a leak occur.

If a drip tray cannot be fitted, then look at other possible options such as:
• Locating the cylinder outside
• Using a continuous flow gas hot water heater

  • As the world’s largest gas appliance manufacturer, Rinnai is widely regarded as the industry leader.
  • Rinnai products are known throughout the world for their superior quality, safety, technology and sophisticated control systems, all factories are ISO 9001 and/or ISO 14001 certified.
  • We have an established 40 year history in New Zealand.
  • Rinnai are happy to advise that we now have an IANZ accredited Test Lab for MEPS testing on Hot Water Cylinders. The lab uses the latest in test equipment and can test all type of Hot Water Cylinders for MEPS heat loss testing.

We realise there's a lot of information out there. Water heating is important and it's better to spend the time up front deciding on what you need and what's important.

We have an experienced customer service team that can walk you through the process. For those more complicated projects we also have a free specification service. Give us a call: 0800 RINNAI (0800 746 624)

Installation costs are difficult to provide as every installation is different. Factors such as the length of pipe required, whether you have accessories fitted, how far away you live and choosing an internal or an external unit all influence the overall cost.

If you’re interested in a Rinnai hot water heating solution, we highly recommend you contact a plumber/gas fitter who will be able to explain all the options to you.