Direct Unvented

The electrically heated Direct cylinders are designed for instances where the use of fossil fuels is impractical / unavailable. 

Featuring two immersion heaters*, one heating the entire cylinder volume and the other heating a boost volume at the top, the cylinders are able to make use of the Economy 7 tariff in order to minimise the cost of hot water. 

If used in this way, the cylinder should be sized to provide the complete anticipated daily hot water use, thereby reducing the use of the boost element which runs on the more expensive standard tariff.

Purchase Info
Warmflow Hot Water Cylinders, Direct 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

  • DI90UV (90l)
    DI120UV (120l)
    DI150UV (150l)
    DI180UV (180l)
    DI210UV (210l)
    DI250UV (250l)
    2077
  • Overall height (mm)
    767
    952
    1142
    1327
    1517
    1767
    2077
  • Secondary return connection (mm)
    n/a
    n/a
    n/a
    n/a
    1223
    1473
    1783
  • Primary coil upper connection (mm)
    n/a
    482
    577
    670
    765
    890
    1045
  • Primary coil lower connection (mm)
    243
    243
    243
    243
    243
    243
    243
  • Cold water capacity (litres)
    89
    118
    148
    178
    208
    248
    298
  • Weight when full (kg)
    109
    142
    175
    207
    243
    286
    340
  • Standing heat loss (kWh/24h)
    0.97
    1.16
    1.36
    1.55
    1.74
    1.99
    2.32
  • Heat up time by lower immersion (mins)
    95
    126
    157
    189
    220
    262
    315
  • Heat up time by upper immersion (mins)
    n/a
    63
    79
    95
    110
    131
    157

View our Cylinders range

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Warmflow Hot Water Cylinders, Direct Unvented hot water cylinder UK, Ireland, Northern Ireland Product

Direct Unvented

The electrically heated Direct cylinders are designed for instances where the use of fossil fuels is impractical / unavailable.

View >