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System Details - Page 7
3.3 Pipework
1. The sizes of the flow and return pipes from the boiler
should be determined by normal methods according to the
requirements of the system.
2. It is recommended that the system is designed for an
11°C (20° F) drop in temperature across the system.
3.4 System Controls
1. For optimum operating conditions, the system in which
the appliance is installed should include a control system.
2. Such a system would comprise a timer control and a
separate room and/or cylinder thermostat as appropriate.
3. The boiler should be controlled so that it operates on
demand only.
4. It is not economical to rely on the boiler thermostat to
control operation of the system.
3.5 Fully Pumped System
(Fig. 3)
1. The sizes of the system pipes should be determined by
normal methods.
2. The open vent pipe should be a minimum of 22mm and
must rise continuously to a point above the teed and
expansion tank.
3. The flow pipe from the boiler may form part of the vent
pipe. No part of the open vent should contain a valve.
