8
classic m -
Installation & Servicing
GENERAL
Ecl 1604
3
OPEN VENT SYSTEM REQUIREMENTS
4
SCHEMATIC PIPEWORK AND SYSTEM BALANCING
The boiler does not normally need a
bypass but at least some radiators on the
heating circuit, of load at least 10% of the
minimum boiler output, must be provided
with twin lockshield valves so that this
minimum heating load is always available
(see footnote re. thermostatic radiator
valves).
Balancing
1.
Set the programmer to ON for both
CH and HW. Turn the cylinder
thermostat down. Close the manual
or thermostatic valves on all radiators,
leaving the twin lockshield valves (on
the radiators referred to above) in the
open position. Turn up the room
thermostat and adjust these lockshield
valves to give boiler flow and return
temperatures not more than 20
o
C
apart. These valves should now be left
as set.
2.
Open all manual or thermostatic
radiator valves and adjust the
lockshield valves on remaining
radiators to give around 11
o
C
temperature drop at each radiator.
3.
Turn up the cylinder thermostat and
adjust the cylinder balancing valve so
that the cylinder achieves a maximum
flow consistent with adequate flow to
the radiators. Check that with only the
domestic hot water loop in circuit a
differential temperature of 20
o
C
across the boiler is not exceeded.
4.
Adjust room and cylinder thermostats
and programmer to NORMAL settings.
The system should be vented directly off the boiler flow pipe, as close to the
boiler as possible. The cold feed entry should be inverted and MUST be
positioned between the pump and the vent, and not more than 150mm (6")
away from the vent connection.
Note.
Combined feed and vent pipes may also be fitted.
There should be a minimum height, 450mm (18"), of open vent above the
cistern water level. If this is not possible refer to
Frame 5
.
The vertical distance between the highest point of the system and
the feed/expansion cistern water level MUST not be less than 450 mm (18").
The pump must be fitted on the flow side of the boiler.
A suitable pump is a domestic circulator capable of providing a maximum
11
o
C (20
o
F) temperature differential across the boiler with the whole of the
heating circuit open (e.g. Grundfos UPS 15/50, 15/60 or equivalent). With the
minimum flow circuit allowed by the controls the differential must not exceed
25
o
C.
The vertical distance between the pump and feed/expansion cistern MUST
comply with the pump manufacturer's minimum requirements, to avoid
cavitation. Should these conditions not apply either lower the pump position
or raise the cistern above the minimum requirement specified by
Caradon
Plumbing Ltd.
The isolation valves should be fitted as close to the pump as
possible.
Ecl 1605
Note.
Systems incorporating zone valves which
could completely shut off the flow through
the system, must be wired such that the
boiler will not fire or continue to fire when
this occurs.
Содержание Classic m3050
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