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10.2
HEATING BOILERS
10.2.1
GENERAL
The Mini Copper-Fin boiler requires a minimum water flow rate through the heat exchanger. A suitably sized
primary circulating pump is available from Lochinvar Limited as an ancillary option.
Recommended pipework layouts are available; please contact Lochinvar Limited for details. When multiple units
are connected using common pipework, it is recommended that a reverse-return arrangement is used to ensure
equal flow through each unit.
The requirements of minimum water flow are given in Table 10.4. Recommendations for the water circulation
system are given in BS6644 and CP 342. The following notes are of particular importance.
1.
Circulating pipework not forming part of the useful heating surface should be insulated. Cisterns,
expansion vessels and pipework situated in areas exposed to freezing conditions should also be
insulated.
2.
When the unit is being utilised as a combined central heating and domestic hot water boiler the hot water
vessel must be of the indirect type.
3.
Drain valves must be located in accessible positions that will permit draining of the entire system
including the unit.
4.
Tapping sizes for connection to the heating system are detailed in Table 3.1.
5.
Ideally, individual valves should be fitted to each unit to enable isolation from the system. The
arrangement must comply with the requirements of BS6644.
6.
Every system should be provided with a water gauge complete with isolating valve so that the pressure
of the system may be displayed for commissioning and maintenance purposes.
10.2.2
OPEN VENTED SYSTEM ARRANGEMENT
The Lochinvar Mini Copper-Fin can be used in an open vented arrangement provided that a vent pipe in
accordance with CP342 or BS6644 as appropriate is fitted. The minimum static head requirement for an open
vented system is 0.5 bar.
10.2.3
SEALED SYSTEM ARRANGEMENT
If a sealed system arrangement is required, a suitable pressurisation unit is available from Lochinvar Limited on
request. Sealed systems should incorporate a safety valve with a lift pressure no greater than the maximum
pressure rating of any component in the heating system. The maximum working pressure of the boiler is 11.0 bar.
A suitably sized expansion vessel should also be fitted to the system.
10.2.4
DRAIN VALVES
Each unit should be provided with a 15mm drain valve fitted into the return to enable the heat exchanger to be
drained without draining the entire system.
