Twin Coil Unvented

Our Twin Coil models have all the features and benefits of the Indirect models but come with an additional coil for use with a renewable heat source, or an additional boiler.

The models feature large dedicated renewable volumes, making them suitable for use with solar thermal systems in line with the recommendations in the Domestic Building Services Compliance Guide 2010.

The renewable coil (the lower of the two coils) has a large surface area to maximise the use of available low grade heat from a renewable resource. The cylinder thermostats for both coils are factory-fitted and an immersion heater is supplied for back-up. All Twin Coil models feature a dedicated 22mm connection for use with a secondary return (pumped circulation).

Purchase Info
Warmflow Hot Water Cylinders, Twin Coil Unvented hot water cylinder UK, Ireland, Northern Ireland Product

Key features

  • 1 of the top 3 performing cylinders in the UK
  • Efficient coil-in-coil design
  • Duplex Stainless Steel
  • Part L Approved
  • Seamless Welding
  • WRAS Approved
  • KIWA Approved
  • Recycled materials used in construction
  • Honeywell Diverter Valve

Good to know

Because we use a thicker layer of high quality polyurethane insulation our cylinder range has amongst the lowest fully certified heat loss levels currently on the market, saving precious fuel and reducing carbon dioxide emissions.

Our insulation is also CFC/HCFC-free, has a zero Ozone Depletion Potential (ODP) and a Global Warming Potential of only 2. Due to the large surface areas of our coil-in-coil heat exchangers it is also possible for a condensing boiler to work in condensing mode for longer, and cycle less frequently when heating the hot water, thereby helping to further reduce fuel use and emissions.

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Cylinder Stats

  • TW210UV (210L)
    TW250UV (250L)
    TW300UV
  • Overall height (mm)
    1517
    1767
    2077
  • Secondary return connection (mm)
    1223
    1473
    1783
  • Primary coil upper connection (mm)
    1078
    1078
    1388
  • Primary coil lower connection (mm)
    978
    978
    1288
  • Renewable coil upper connection (mm)
    532
    532
    532
  • Cold inlet connection (mm)
    482
    482
    482
  • Renewable coil lower connection (mm)
    432
    432
    432
  • Cold water capacity (litres)
    201
    240
    290
  • Weight when full (kg)
    242
    287
    340
  • Standing heat loss (kWh/24h)
    1.74
    1.99
    2.32
  • Dedicated renewable volume (litres)
    100
    100
    150
  • Primary coil rating @ 15/L/min (kW)
    21.3
    20.2
    21.0
  • Renewable coil rating @ 15/L/min (kW)
    22.3
    22.0
    20.7
  • Heat up time (EN12897) by primary coil (mins)
    16
    23
    22
  • ErP Rating boiler icon

View our Cylinders range

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