Ferroli DOMINA N 80 DGT, Installation, Service And User Manual

Page: 10 / 48

DOMINA N 80 DGT
10
NOTE: A bypass that will ensure a minimum fl ow rate of
6 l/min. at all all time must be fi tted as far as possible
from the boiler if thermostatic radiator valves are fi tted
thoughout.
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 underfl oor 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 fi g. 9.
Important - If thermostatic radiator vales are fi tted a bypass must be fi tted to ensure a minimum fl ow rate through
the boiler of 6 l/min . The bypass should be fi tted 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 fi lling 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 fi lling loop is shown in fi g. 10.
Domestic Hot Water
Always fi t 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 fi tted 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.
Filling
point C.H.
Bypass
Fig. 10
Key
1. Filling point C.H.
2. Temporary connection
3. Cold water supply