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Service Call 0844 736 9138, Technical Help (Chargeable) Call 0906 802 0253
General
This boiler is designed for use as part of a sealed water central
heating system with fully pumped circulation. The pump,
expansion vessel and associated safety devices are all fi tted
within the boiler.
Safety valve
The safety valve is an integral part of the boiler and it cannot
be adjusted. The pipe from the safety discharge valve must
discharge safely in accordance with standards.
Expansion vessel
The boiler has an integral expansion vessel with a capacity of 8
litres (1.76 gallons), with a charge pressure of 0.75bar.
The heating system volume should be calculated to
ensure that the expansion vessel is suitable, it may
be necessary to add an additional vessel.
- In GB, Guidance on vessel sizing is also given in the current
issue of BS5449 and BS7074 Part 1.
- In IE, current edition of I.S.813 “Domestic Gas Installations”.
Bypass
The boiler is fi tted with an automatic bypass.
• Ensure that under no circumstances does the fl ow rate drop
below the fi gure specifi ed, refer to chapter "Technical data".
Filling the sealed system
Suitable external fi lling systems are shown diagrammatically,
see diagram - Heating circuit design.
The system should be pressurised to 1.0bar, indicated on the
digital display with no heating demand.
Drain points
Drain taps must be provided at all low points of the system,
which will allow the entire system to be drained.
Drain taps shall be to the current issue of BS2879.
Water treatment
Existing system
- It is essential that prior to installing the new
boiler the system is thoroughly fl ushed.
New system
- For optimum performance after installation, the
boiler and its associated central heating system should also be
fl ushed.
Flushing shall be carried out in accordance with BS 7593, a
chemical cleanser can be used either Sentinel X300, X400 or
Fernox F3 are suitable.
It is recommended to fl ush existing systems fi rst before fi tting
the new boiler.
• Ensure all cleanser is removed from the whole system before
adding an inhibitor.
For long-term corrosion protection after fl ushing, an inhibitor
suitable for stainless steel heat exchangers can be used. Either
Sentinel X100 or Fernox F1 inhibitor can be used.
The boiler is suitable for use on systems using softened water.
7.3
Dimensions
425
24kW=
310
28kW=
340
130
740
7.4
Mounting
• Make sure that the equipment used for implementing the
installation is compatible with that of the appliance.
• Determine the assembly location. See the "Appliance
location" chapter.
