Potterton 80e, Инструкция по установке и обслуживанию, Страница: 13 / 52

Installation Requirements - Page 12
External Controls
To obtain economical use of the appliance it is advisable to
fit external controls. The controls can take the form of:-
a) Time clock (two internal options are available
Part No. 31-19053 - Electro-mechanical)
Part No. 31-19054 - Electronic).
b) Room thermostat
c) Thermostatic radiator valves (TRV's)
d) Zone valves
A combination of these controls will produce economical and
effective use of the heat generated by the boiler. It is
advisable to control the temperature of the main living area
with a room thermostat and other areas by TRV's.
Frost Protection
The appliance is fitted with an internal Frost Thermostat,
however this device is purely for the protection of the
appliance. If any other part of the central heating system
requires frost protection, an external frost thermostat must
be fitted in the usual manner, refer to Fig. 12 for wiring.
1.6 Mains Water Feed: Central Heating
A connection must be incorporated into the central heating
system to facilitate filling. There must be no direct
connection to the mains water supply, even through a non-
return valve, without the approval of the Local Water
Authority.
PERMISSIBLE METHODS OF FILLING
Note: The Puma combination boiler range is fitted with a
diverter valve design which does not have a manual
operation lever to aid filling. Therefore to ease filling of the
central heating system an air bleed valve is fitted to this
diverter and must be opened during filling until water flows
out. The valve should then be closed. (Fig.16).
(1) DIRECT METHOD
(Fig. 8)
A detachable flexible hose is connected to a stop valve fitted
to an outlet on the service main. The other end of the hose
is connected to a second stop valve and a double check
valve. The double check valve is fitted to an inlet connection
on the central heating return pipe under the appliance. The
hose should be disconnected after filling. Where the mains
pressure is excessive a pressure reducing valve shall be
used to make filling easier. The following fittings shall form a
permanent part of the system and shall be fitted in the order
stated.
a) A stop valve complying with the requirements of BS
1010 Part 2, (the temporary hose from the draw off tap
shall be connected to this fitting).
b) Double check valve of an accepted type.
(2) BOOSTER PUMP METHOD
The system may be filled through a self contained unit
comprising a cistern, pressure booster pump and if
necessary, an automatic pressure-reducing valve or flow
restrictor.
The pressure booster pump must be capable of pressurising
the system to a minimum of 1.0 bar (14 p.s.i.) measured at
the appliance.
The cistern should be supplied through a temporary
connection from a service pipe or cold water distributing
pipe. The unit may remain permanently connected to the
heating system to provide limited water make-up.
Provisions for make up water
Provision should be made for replacing water loss from the
system by re-pressurisation of the system. See section on
Methods of Filling.
Reference should be made to British Gas Publications
"Material and Installation Specifications for Domestic Central
Heating and Hot Water".
1.7 Installation to an Existing Central
Heating System
The boilers are designed to operate on a sealed system
only, therefore if the existing system is of the open type it will
have to be modified to comply with BS 6798.
Before installing a new combination boiler to an existing
system flush out the old system with a recommended
descaling/flushing agent at least twice.
Also check pipework and renew any corroded pipework or
fittings. Valve glands must be re-packed or replaced
wherever necessary and any defective controls replaced.
1.8 Hard Water Areas
If the area of installation is recognised as a hard water area,
(above 200 p.p.m.) it is essential that a suitable water
treatment device of an electronic, magnetic or galvanic type
be installed in the mains water supply.