MP indoor SS single thermosiphon wetback coil Ø550mm

Overview

Discontinued

Superseded Jul 2022 by the improved Ø560mm cylinders.

Wetback is something that you mostly associate with an old house with a low pressure copper cylinder connected to an old wood burner. With a Rinnai thermosiphon cylinder you can now have a new modern house with mains pressure water heated by your wetback fire, saving you money on your power bill.

Thermosiphon coil for wetback
Water is circulated through a coil inside the cylinder by a thermosiphon effect, i.e. warmer water rises and cooler water falls, creating a natural flow. This means there is no need for a pump to circulate water, you can still heat your water even if there's a power cut.

Eco inlet
Added benefit of an eco inlet that allows connection to an open loop* (potable) solar system, or a hot water heat pump.

* For open loop solar systems the potable water (suitable for drinking and food preparation) from the cylinder flows through the collector—water that flows through the system is used directly by the household.

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Product Details

Suitable for:
- indoor installations only
- mains and low pressure systems
- connection to a wetback fire and/or an open loop solar system or hot water heat pump
- residential and light commercial water heating applications

No suitable as a pool or spa heater, or for underfloor heating.

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.

Single thermosiphon coil lower element
For new builds and renovations connecting to a wetback fire, where the homeowner will have full electric boost when there is not enough heat from the wetback fire. System can also be connected to an open loop solar or hot water heat pump.

Single thermosiphon coil dual element
For new builds and renovations connecting to a wetback fire, where the homeowner wants faster recovery times, and to reduce the risk of running out of hot water. Cylinder will have higher running costs. System can also be connected via the eco inlet to an open loop solar system or hot water heat pump.

Single thermosiphon coil upper element
For new builds and renovations connecting to a wetback fire, where the homeowner relies heavily on heat from the wetback and/or open loop solar system or hot water heat pump. Upper element is only used to quickly heat water in the top of the cylinder.

Technical Specifications

Warranty

10 years

IP rating

IPX1

TPR

supplied


Single thermosiphon coil lower element codes
  • 190 L 2 kW - MS190550CT20
  • 190 L 3 kW - MS190550CT30
  • 250 L 2 kW - MS250550CT20
  • 250 L 3 kW - MS250550CT30
  • 300 L 2 kW - MS300550CT20
  • 300 L 3 kW - MS300550CT30
Single thermosiphon coil upper element codes
  • 250 L 2 kW - MS250550CTU20
  • 250 L 3 kW - MS250550CTU30
  • 300 L 2 kW - MS300550CTU20
  • 300 L 3 kW - MS300550CTU30
Single thermosiphon coil dual element codes
  • 250 L 2 kW - MS250550CTD20
  • 250 L 3 kW - MS250550CTD30
  • 300 L 2 kW - MS300550CTD20
  • 300 L 3 kW - MS300550CTD30
Construction

Inner, high grade duplex stainless steel
Outer, galvanised steel

Insulation

CFC free polyurethane foam, compliant with NZ MEPS

Coil
  • Wetback thermosiphon coil 1 " 25 mm diameter
  • Length = 10 m (0.785 m2)
  • Maximum kW rating 13.4 kW
Element

Incoloy 825 alloy sheath element, options; 2 kW, 3 kW, 2 x 2 kW, and 2 x 3 kW

Thermostat

Robert Shaw 30 A contact auto-reset (red dial)

TPR

TPR supplied, 850 kPa, 99 °C, 46 kW

Weights
Model Empty Full
190 L 42 kg 232 kg
250 L 48 kg 298 kg
300 L 56 kg 356 kg
Compliance

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

Market release

September 2017: 250 L and 300 L 
September 2018: 190 L

Superseded

Superseded Jul 2022 by the improved Ø560mm cylinders.

Common spares
  • Thermostat Robert Shaw red dial (ART solar) - 30015
  • Element MP SS 2 kW curved - 30002
  • Element MP SS 3 kW curved - 30004
  • TPR MP 850 kPa HT575 20 mm 99 °C, 46 kW - BE11004781