GENERAL
8
Mexico Slimline CF440 -
Installation & Servicing
1.
Open vent and cold feed connections must be made to the
boiler flow and return tappings, according to the options shown
in Frame 1.
2.
The boiler is assumed to be the highest point of the circulating
system.
3.
The circulating pump is positioned on the FLOW and the vertical
distance, between the pump and feed/ expansion tank, 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 feed/ expansion tank
above the minimum requirements of
Caradon Ideal Limited.
4.
The water velocity through the boiler flow/return pipes is
assumed to be below 1 m/s (3 ft./s), whilst the pump flow rate is
set to provide a temperature difference of 11
o
C (20
o
F) across
the boiler flow/return, at design input.
5.
This information is intended as a GUIDE ONLY and cannot take
into account instantaneous changes in heat caused by the
operation of motorised valves, pumps etc.
Due allowance MUST be made if surging is liable to occur.
If in any doubt, contact
Caradon Ideal Limited.
3
MINIMUM REQUIREMENTS
Fully pumped systems
4
GRAVITY HOT WATER & PUMPED CENTRAL HEATING
1.
Separate flow and return connections are used for each service.
All possible configurations are given in Frame 1 but
ONLY those
shown should be used.
2.
The use of a cylinder thermostat is recommended. This will
prevent excessive DHW temperatures and thus reduce gas
consumption.
3.
The schematic pipework graph is based on the assumption that
NO MORE than 8 elbows are used in the gravity loop, including
entry to the boiler.
4.
For each extra elbow in excess of 8, (R) MUST be reduced by 300
mm (12") or (H) increased by 100 mm (4")
5.
Whatever value is selected for (R) the value of (H) MUST be at
least that indicated by the graph.
Notes.
a.
Flow and return pipes should rise vertically on leaving
the boiler.
b.
Horizontal pipes should be ABOVE ceiling level and as
short as possible.
c.
A MINIMUM inclination of 25 mm per 3 m run (1" per 10')
is required to avoid air locks.
If the above conditions cannot be met pumped primaries
should be used.
R
= the horizontal distance between the centre line of the
cylinder and the boiler tappings used (measured
along the pipe run).
H
= the vertical distance between the top of the boiler
and the base of the cylinder.
200946-1.p65
3/9/2004, 3:30 PM
8
