Heating System Design - gledhill TORRENT DIRECT Design, Installation & Servicing Instructions

4.1 BALL VALVE AND OVERFLOW
4.1.1 Torrent Direct models
The Torrent Direct models are designed for supplying hot water only and the feed and expansion
cistern only supplies the thermal store. The feed and expansion cistern can be filled manually if
required e.g. using a hose pipe fitted with a double check valve.
In this situation an overflow pipe can still be fitted if required to ensure that if a leak occurs on the
internal dhw heat exchanger it can be discharged safely to the outside of the building.
Note: If a ball valve is fitted, then a warning/overflow pipe must always be fitted.
4.1.2 Torrent Indirect and Torrent RE-Solar models
These models are supplied with a feed and expansion cistern, ball valve and float. In most
installations these supply the whole primary/heating system and therefore a ball valve and
overflow pipe must be installed in the feed and expansion cistern.
4.2 WATER TREATMENT
In all Torrent models, the primary (i.e. non-potable) water is stored and the domestic hot water is
heated instantaneously by means of heat exchangers. Therefore treating the primary water will
not contaminate the domestic hot water supply.
Although the Torrent primary store has no special water treatment requirements, the radiators
and other parts of the circuit will require the application of a scale and corrosion inhibitor. The
volumes and concentration should be calculated in accordance with the manufacturers
instructions and when calculating the system volume (i.e. the water content), the volume of the
Torrent should be taken into account.
4.3 TORRENT DIRECT SYSTEM DESIGN
The Torrent Direct model shown in figure 1.1, has been designed to generally operate with an off-
peak supply and is provided with two side entry 3kW immersion heaters. The lower immersion
heater heats the whole of the store and is normally connected to the off-peak supply. The top
immersion heater heats 50 – 70 litres of water (depending upon the model) at the top of the store
This is connected to the unrestricted on-peak supply and is switched on manually for a pre-set
time period by the householder using the off-peak controller to boost the hot water if and when
required.
The schematic arrangement of the wiring for the Torrent Direct is shown in figure 4.1. The whole
of the electrical installation shall be designed and installed by a competent person and fully in
accordance with the latest edition of the 'Requirements for Electrical Installations, BS 7671'

HEATING SYSTEM DESIGN

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