MODENA 80 E
10
Fig. 9
Central Heating
Detailed recommendations are given in BS6798, BS5449, BS6700 and CP342 Part 2. Pipework not forming part of
the useful heating surface should be insulated to prevent any heat losses or possible freezing (i.e. in roof spaces or
ventilated underfloor spaces). Drain taps should be positioned at the lowest point of the system in accessible
locations to permit the whole system to be drained down. The drain taps should be in accordance with BS2879.
Copper tubing to BS2871, Part 1 is recommended for water carrying pipework. Pipework in horizontal runs should
have a gradient where possible to facilitate the removal of air. Ensure that the boiler heat exchanger is not a natural
point for air collection. A typical heating system with domestic hot water circuit is illustrated in fig. 9.
Important - If thermostatic radiator vales are fitted a bypass must be fitted to ensure a minimum flow rate through
the boiler of 6 l/min. The bypass should be fitted as far as possible from the boiler.
Make Up Water
Provision must be made for replacing water lost from the sealed system. Reference should be made to BS6798, for
methods of filling and making up sealed systems. There must be no direct connection between the boiler's central
heating system and the mains water supply. The use of mains water to charge and pressurise the system directly,
is conditional upon the Local Water Byelaws. Again any such connection must be disconnected after use. A typical
temporary filling loop is shown in fig. 10.
Domestic Hot Water
Always fit a scale reducer in "hard water areas" (18 clarke degrees or over)". A 15mm copper connection point on
the boiler for attaching to the main supply is provided. The maximum domestic water pressure for the inlet supply
is 10 bar (145 P.S.I.). If the cold mains supply exceeds 5 bar (72 P.S.I.), a water governor or pressure reducing
valve must be fitted by the installer into the mains supply in an inconspicuous but accessible position preferable
between 3 and 5 metres (10-16ft) before the appliance. Such a valve must be approved by the Water Research Council.
Attention - is drawn to the Model Water Byelaws.
Fittings manufactured from duplex (alpha-beta) brass are not acceptable for underground use and certain water
undertakings will not accept their use above ground.
Ensure all pipework is adequately supported
Gas
Cold water
Additional expansion
vessel C.H. (if required)
Filling
point
C.H.
Bypass
NOTE: A bypass that will ensure a minimum flow
rate of 6 L/m at all times must be fitted as far as
possible from the boiler if thermostatic radiator
valves are fitted.
Key
1. Filling point C.H.
2. Temporary connection
3. Cold water supply Fig. 10
