Enamel Mains Pressure Indoor 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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Suitable for 

  • indoor and outdoor installations
  • mains and low pressure systems
  • residential and commercial water heating applications
  • right hand plumbing connections (90, 135, 180 L)
  • left or right hand plumbing connections (215, 275, 340 L)

Hard or aggressive water will need to be treated in order to use this product, please test before use.

Not suitable as a spa or pool 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.


Warranty 7 Years

IP rating IPX1

TPR Supplied


Cylinder Recovery Times (theorectical)

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

• 90 L 2 hrs 38 mins 2 kW (34.3 L/h) 1 hr 45 mins 3 kW (51.7 L/h)

• 135 L 3 hrs 56 mins 2 kW (34.6 L/h) 2 hrs 37 mins 3 kW (51.3 L/h)

• 180 L 5 hrs 15 mins 2 kW (34.3 L/h) 3 hrs 30 mins 3 kW (51.4 L/h)

• 215 L 3 hrs 29 mins 3.6 kW (61.8 L/h) -

• 275 L 4 hrs 28 mins 3.6 kW (61.7 L/h) -

• 340 L 5 hrs 31 mins 3.6 kW (61.7 L/h) -


Pressure Limiting Valve

500 kPa (approx.) all models


Hot and cold water connections ¾ " (20 mm)


High quality glass lined (vitreous enamel) inner cylinder. Sturdy corrosion resistant outer casing, and high density expanded polyurethane foam insulation.


cTech element positioned at the bottom of the cylinder

Maximum working pressure

850 kPa

Pressure testing

To 15 Bar


Thermal insulation

CFC-free polyurethane foam, compliant with MEPS standard


The thermostat setting is between 60-75 °C. Maximum thermostat setting, in order to maintain the warranty, is 75 °C.


TPR valve

Rating of the TPR supplied with the cylinder is 10 kW / 850 kPa, 99 °C


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



Is a safe tray required for a like-for-like HWC replacement?

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


There are so many similar products around, what does Rinnai provide that the others don't?

  • 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.

I'm not really clear on any option and it's all getting a bit too confusing, what should I do?

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.

I’m trying to factor costs and then compare what’s best. I can find out the cost of the different products but what about installation costs?

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.