Twin coil systems, save money on power in summer using solar water heating through the standard coil, and in winter heat the water by the wetback fire using the thermosiphon coil.
The thermosiphon coil for wetback has the water circulating 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's no need for a pump to circulate the water, you can still heat your water even if there's a power cut.
Product Details
Suitable for:
- indoor installations only
- mains and low pressure systems
- connection to a wetback fire and closed loop* solar system
- residential and light commercial water heating applications
Not 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.
Twin coil lower element
- For new builds and renovations connecting to a wetback fire and a closed loop solar system, where the homeowner will have full electric boost when there is not enough heat from the supplementary heating sources.
Twin coil dual element
- For new builds and renovations connecting to a wetback fire and a closed loop solar system, where the homeowner wants faster recovery times, and to reduce the risk of running out of hot water. Cylinder will have higher running costs.
Twin coil upper element
- For new builds and renovations connecting to a wetback fire and closed loop solar system, where the homeowner relies heavily on heat from the supplementary heating sources. Upper element is only used to quickly heat water in the top of the cylinder.
* For closed loop solar systems the heat transfer fluid is circulated through the solar collector on the roof where it is heated by the sun. The heated transfer fluid then passes through the cylinder coil, which acts like a very large element to heat the water.
Technical Specifications
Twin coil lower element codes
- 250 L 2 kW - MS250560CCT20
- 250 L 3 kW - MS250560CCT30
- 300 L 2 kW - MS300560CCT20
- 300 L 3 kW - MS300560CCT30
Twin coil upper element
- 250 L 2 kW - MS250560CCTU20
- 250 L 3 kW - MS250560CCTU30
- 300 L 2 kW - MS300560CCTU20
- 300 L 3 kW - MS300560CCTU30
Twin coil dual elements
- 250 L 2 kW - MS250560CCTD20
- 250 L 3 kW - MS250560CCTD30
- 300 L 2 kW - MS300560CCTD20
- 300 L 3 kW - MS300560CCTD30
Construction
- Inner, high grade duplex stainless steel
- Outer, galvanised steel
Insulation
- CFC free polyurethane foam, compliant with NZ MEPS
Connections
- Hot and cold connections " (20 mm)
- TPR " (20 mm)
Coil wetback
- Wetback thermosiphon coil 1 " 25 mm
- Length = 10 m (0.785 m2)
- Maximum kW rating 13.4 kW
Coil solar
- Solar coil " 20 mm diameter
- Length 14 m (1.1 m2)
- Maximum kW output 21.4 kW
Element
- Incoloy 825 alloy sheath element, options; 2 kW, 3 kW, 2 x 2 kW, 2 x 3 kW
Thermostat
- Robert Shaw 30 A contact auto-reset (red dial)
TPR
- TPR supplied, 850 kPa, 99 °C, 46 kW
Pressure limiting valve
- This cylinder MUST be installed with a 500 kPa or less pressure limiting valve and appropriate cold water expansion valve
Weights
| Model | Empty | Full |
| 250 L | 55 kg | 305 kg |
| 300 L | 62 kg | 362 kg |
Compliance
- No cylinder wrap required. All Rinnai cylinders meet the NZ Minimum Energy Performance Standard (MEPS).