Main Direct Unvented 120L Hot Water Cylinder - 720635901

£488.02 (Inc. VAT)

In Stock




Main Unvented Hot Water Cylinders are designed help save the environment and minimise fuel bills. The range has six direct and six indirect models, which are designed to work with Main Eco Elite System boilers, providing the complete solution for your project. The indirect heating coil is fitted with an electric immersion heater as back up, so you can be confident of having hot water, whenever you need it.

The cylinders are easy to install, with front access to controls and connections. The coil-in-coil heat exchanger ensures rapid heat recovery and 50mm of factory injected polyurethane foam ensures that heat loss and running costs are kept to a minimum. The high grade stainless steel inner cylinder ensures a long product life with low maintenance.


  • One year parts and labour warranty*
  • 25 year warranty on stainless steel inner vessel*
  • Indirect heating coil (factory fitted with an electric immersion heater as back up)
  • Coil-in-coil heat exchanger
  • High grade stainless steel cylinder
  • Low heat loss
  • Incoloy 800 alloy sheathed elements
  • KIWA approved
  • Manufactured in the UK
  • *Subject to registration

Fixing - Feet on bottom moulding for floor mounting.

Plumbing connections - Inlet/Outlet, 22mm compression fittings / ¾" BSP

parallel thread.

Primary coil - 22mm compression fittings / ¾" BSP parallel thread.

Temperature and pressure relief valve - 15mm compression outlet.

Cold water control - Integrated cold water control set comprising pressure

reducing valve and strainer - factory set at 3.5 bar, expansion relief valve -

factory set at 6 bar and check valve. 22mm compression fittings.

Mains pressure - Min 1.5 bar, Max 16 bar. A 2-port motorised valve is

supplied with indirect models.

Flow rates - Up to 55 litres per minute @ 6 bar pressure.

Operating pressure - 3.5 bar.

Expansion relief valve pressure - 6.0 bar.

Operating temperature - Recommended 60°C. Adjustable 10-70°C.

Water expansion - Remote expansion vessel

12 litre vessel supplied with 120 and 150 litre models.

18 litre vessel supplied with 170 and 210 litre models.

24 litre vessel supplied with 250 and 300 litre models.

Minimum water supply requirements - Recommended minimum supply

pressure - 1.5 bar/20 l/min flow rate.

Secondary circulation - Via 22 x 22 x 15mm swept tee, which should be fitted

to the inlet pipework. Secondary Circulation is not recommended for direct units

being used with off-peak electricity tariffs.

Pressure testing - Units are tested to 15 bar.

Tundish - 15mm compression inlet and 22mm compression outlet.


Indirect models - Controls should be wired to the boiler, programmer etc,

in accordance with the control scheme being used.

Direct models - Connection is direct to terminals in the immersion heater which

must be permanently connected to the supply through a double-pole lined

isolating switch with a minimum breaking capacity of 13A.

All electrical wiring must conform to the latest IEE Wiring Regulations.

Making the decision on the most suitable kind of Cylinder is an important decision. After you decide that Direct Unvented Cylinders deliver the right solution then the Main Direct Unvented 120L Hot Water Cylinder - 720635901 is without doubt worth adding to the shortlist.


Main Direct Unvented 120L Hot Water Cylinder - 720635901 Specifications
Mounting Floor
Diameter (mm) 550
Capacity (Litres) 120
Material Stainless Steel
Connection Size 2.5 mm
Range Main
EAN 5033313021573
MPN 720635901
Product Code 176182
Cylinder Type Unvented Cylinder
Indirect / Direct Cylinder Direct
Colour White
Warranty (Years) 25
Height (mm) 931
Weight (Kg) 25
Orientation Vertical

Main Direct Unvented 120L Hot Water Cylinder - 720635901


£488.02 (Inc. VAT)

Stock status: In Stock

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30 Day Returns

Returns Policy - Changed Your Mind?

If you change your mind about the product when you receive it you can notify us any time within 30 days and return it for a full refund at your own cost. Any refunds will be made within 30 days of receiving your returned item. You are expected to cover the cost to return the item and your initial delivery charge will not be refunded.

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