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22
MHG Heating Ltd Unit 4 Epsom Dow ns Metro Centre, Waterfield, Tadw orth, Surrey KT20 5LR
Telephone 01737 358000 Fax 08456 448803 Email
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010717
8.0 Filling The System
The Initial filling of a sealed heating system, and subsequent refilling, must be by a method that has been
approved by the Water Regulation Advisory Scheme (WRAS) for that type of heating system.
i.e
Non Domestic (Other than
In-House
)
Fluid Category 4 (
C-4
)
For Category 4 systems, the approved method of filling must comprise of the following components in the
arrangement shown;
Control Valve.
Strainer.
Verifiable Backflow Device with Reduced
Pressure Zone (RPZ Valve)
Incorporating a ‘Type BA’ Air Gap.
Tundish.
Control Valve.
Furthermore, in accordance with BS 6644: 2011 system with an input greater than 70kW (nett), an automatic
water replenishment unit shall be installed to automatically replenish any lost or evaporated water.
Please refer to BS 6644: 2011 for allowable water replenishment methods for use with sealed/pressurized
heating systems.
For information on a comprehensive range of pressurization units that comply with current British
Standards and WRAS Regulations, please contact MHG Heating Ltd Sales.
