Installation & Servicing Instructions - Grant UK

For long term protection against
corrosion and scale, after flushing, it is
recommended that an inhibitor such as
Betzdearborn's Sentinel X100 or Fernox
MB-1 is dosed in accordance with the
guidelines given in BS 7593:1992.
Failure to implement these guidelines
will invalidate the warranty.
We recommend that both antifreeze
and corrosion inhibitor be used in the
primary water system.
4.8 Heating System Design
Considerations
To achieve the maximum efficiency
possible from the Grant VORTEX Pro
boiler, the heating system should be
designed to the following parameters:
Radiators:-
• Flow temperature 70°C
• Return temperature 50°C
• Differential 20°C
Underfloor:-
• Flow temperature 50°C
• Return temperature 40°C
• Differential 10°C
Size radiators with a mean water
temperature of 60°C.
Design system controls with programmable
room thermostats or use weather
compensating controls to maintain return
temperatures below 55°C.
!
NOTE
The boiler should not be allowed to
operate with return temperatures of
less than 40°C when the system is up
to operating temperature.
The use of a pipe thermostat is
recommended to control the return
temperature when using weather
compensating controls.
Refer to Section 2.5 for the size and type
of the connections and Section 5 for the
position of the connections.
4.9 Underfloor Heating Systems
In underfloor systems it is essential
that the return temperature must be
maintained above 40°C to prevent
internal corrosion of the boiler water
jacket.
4.10 Pipework Materials
Grant boilers are compatible with both
copper and plastic pipe. Where plastic
pipe is used it must be of the oxygen
barrier type and be of the correct
class (to BS 7291:Part 1:2001) for the
application concerned.
!
WARNING
The first metre of pipework connected
to both the heating flow and return
connections of the boiler must be
made in copper on all types of system
- sealed or open-vented.
4.11 Sealed Systems
If plastic pipe is to be used, the installer
must check with the plastic pipe
manufacturer that the pipe to be used
is suitable for the temperature and
pressures concerned.
Plastic pipe must be Class S to
BS 7291: Part 1:2001.
! NOTE
WARNING
!
The system must incorporate a lowpressure
switch to shut off power to
the boiler if the system pressure drops
below 0.2 bar. A suitable low pressure
switch kit is available to purchase
from Grant UK, Part No. MPCBS 63.
4.12 Underfloor Pipework
Plastic pipe may be used on Underfloor
systems where the plastic pipe is fitted
after the thermostatic mixing valve.
Copper tube must be used for at least
the first metre of flow and return primary
pipework between the boiler and the
underfloor mixing/blending valves.
Boiler Installation
Information
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