Enamel Mains Pressure Indoor Cylinders

High quality hot water cylinders

Easy replacement for your old electric cylinder

Rinnai enamel mains pressure indoor hot water cylinders offer exceptional performance and reliability under a wide variety of water conditions. With a range of slim diameters, they are an easy replacement option for your old electric cylinder.

  • large range of sizes (30-300 L), there's a cylinder to suit every need
  • easy replacement, 488 and 590 mm diameter sizes, matches traditional NZ cylinder sizes

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Product Details

Suitable for:

  • indoor installations only
  • mains and low pressure systems
  • residential water heating applications only

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.  

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


7 years

IP rating





High performance anode fitted


Hot and cold water connections ¾ " (20 mm)


Inner cylinder: High quality glass lined (vitreous enamel) 
Outer casing: Galvanised steel


Long-life Superloy 825 alloy sheathed element. Incorporated into an easily removable outer plate should replacement be necessary.

Maximum operating pressure

850 kPa

Pressure testing

To 15 bar

Thermal insulation

CFC-free polyurethane foam, compliant with MEPS standard


Robert Shaw 30 A contact thermostat, manually resettable at 85 °C

TPR valve

Rating of TPR supplied with cylinder— factory set to 850 kPa and 90 °C.

Model Weight empty  Weight full
30 L 15 kg 45 kg
50 L 20 kg 70 kg
135 L 47 kg 182 kg
180 L 64 kg 244 kg
250 L 81.5 kg 331.5 kg
300 L 98.5 kg 398.5 kg
Cylinder recovery times (theoretical)

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

  • 30 L = 1 hr 10 mins (1.5 kW), 35 mins (3 kW)
  • 50 L = 1 hr 56 mins (1.5 kW), 58 mins (3 kW)
  • 135 L = 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)
  • 300 L = 8 hrs 45 mins (2 kW), 5 hrs 50 mins (3 kW)
  • 300 L = 4 hr 22 mins (2 x 2 kW), 2 hrs 55 mins (2 x 3 kW)

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

Market release

Late 2017

Order codes - undersink
  • MEUS03040015 30 L 1.5 kW (diam. 400 mm, height 540 mm)
  • MEUS03040030 30 L 3.0 kW (diam. 400 mm, height 540 mm)
  • MEUS05048815 50 L 1.5 kW ((diam. 488 mm, height 615 mm)
  • MEUS05048830 50 L 3.0 kW (diam. 488 mm, height 615 mm)
Order codes - standard lower element
  • ME13559030 135 L 3 kW (diam. 590 mm, height 910 mm)
  • ME18059020 180 L 2 kW (diam. 590 mm, height 1200 mm)
  • ME18059030 180 L 3 kW (diam. 590 mm, height 1200 mm)
  • ME25059020 250 L 2 kW (diam. 590 mm, height 1595 mm)
  • ME25059030 250 L 3 kW (diam. 590 mm, height 1595 mm)
  • ME30059020 300 L 2 kW (diam. 590 mm, height 1805 mm)
  • ME30059030 300 L 3 kW (diam. 590 mm, height 1805 mm)
Order codes - standard dual element
  • ME250590D20 250 L 2 x 2 kW (diam. 590 mm, height 1595 mm)
  • ME250590D30 250 L 2 x 3 kW (diam. 590 mm, height 1595 mm)
  • ME300590D20 300 L 2 x 2 kW (diam. 590 mm, height 1805 mm)
  • ME300590D30 300 L 2 x 3 kW (diam. 590 mm, height 1805 mm)

CAD/BIM Downloads


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.