9
isar -
Installation and Servicing
GENERAL
4
SYSTEM REQUIREMENTS - CH (continued) and Hot Water
General
1. The installation must comply with all relevant national and
local regulations.
2. The installation should be designed to work with flow
temperatures of up to 82
o
C.
3. All components of the system must be suitable for a working
pressure of 3 bar and temperature of 110
o
C. Extra care should
be taken in making all connections so that the risk of leakage
is minimised.
The following components are incorporated within the
appliance:
a.
Circulating pump.
b.
Safety valve, with a non-adjustable preset lift pressure of
3 bar.
c.
Pressure gauge, covering a range of 0 to 6 bar.
d.
An 8-litre expansion vessel, with an initial charge pressure
of 0.75 bar.
4. 'Make-up' Water. Provision must be made for replacing water
loss from the system, either :
a.
From a manually filled 'make-up' vessel with a readily
visible water level. The vessel should be mounted at
least 150mm above the highest point of the system and
be connected through a non-return valve to the system,
fitted at least 150mm below the 'make-up' vessel on the
return side of the radiators.
or
b.
Where access to a 'make-up' vessel would be difficult,
by pre-pressurisation of the system.
The maximum cold water capacity of the system should
not exceed 143 litres, if not pressurized. However, if
the system is to be pressurized, the efficiency of the
expansion vessel will be reduced and a larger vessel
(or smaller system volume) may be necessary. If the
capacity of the vessel is not considered sufficient for
this, or for any other reason, an additional vessel
MUST be installed on the return to the boiler.
Guidance on vessel sizing is given in Frame 3.
5. Filling. The system may be filled by the following method:
a.
Through a temporary hose connection from a 'draw-off'
tap, supplied from a service pipe under mains pressure.
Where the mains pressure is excessive a pressure
reducing valve must be used to facilitate filling.
When installing the filling device it must be connected as
shown below, to fully comply with the water regulations.
This may involve the fitting of an additional WRAS
approved isolator valve to the mains supply.
i. Thoroughly flush out the whole system with
cold water.
ii. Fill and vent the system until the pressure
gauge registers 1.5 bar and examine for leaks.
iii. Check the operation of the safety valve by
raising the water pressure until the valve lifts.
This should occur within 0.3 bar of the preset lift
pressure.
iv. Release water from the system until the
minimum system design pressure is reached;
1.0 bar if the system is to be pre-pressurised.
Water Flow Rate and Pressure Loss
Max CH Output
kW
23.4
(Btu/h)
(80 000)
Water flow rate
l/sec
0.37
(gal/min)
4.8
Temperature Differential
o
C
15
(
o
F)
(27)
Head available for
m.w.g.
2.3
system pump.
(ft.w.g.)
7.5
DOMESTIC HOT WATER
1. The domestic hot water service must be in accordance
with BS 5546 and BS 6700.
2. Refer to Table 1 for minimum and maximum working
pressures.
3. The boilers are suitable for connection to most types of
washing machine and dishwasher appliances.
4. When connecting to suitable showers, ensure that:
a.
The cold inlet to the boiler is fitted with an approved
anti-vacuum or syphon non-return valve.
b.
Hot and cold water supplies to the shower are of equal
pressure.
5. Hard Water Areas
Where the water hardness exceeds 200mg/litre, it is
recommended that a proprietary scale reducing device is
fitted into the boiler cold supply within the requirements of
the local water company.
IMPORTANT
Provision MUST be made to accommodate the expansion of
DHW contained within the appliance, if a non-return valve is
fitted to the DHW inlet.
CH Return
Ecl 6053
Hose unions
Mains
water supply
Temporary hose
(disconnect after filling)
Additional
stop valve
Double check valve
assembly
(
note direction of flow
)
Summary of Contents for isar m30100
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