Operating instructions

(Models GCB and GEB Only)

In a domestic hot water system, the hot water storage

vessel must be of the indirect cylinder of calorifier type.

The hot water storage vessel should be insulated,

preferably, with not less than 75mm thick mineral fibre, or

its equivalent.

Pipework not forming part of the useful heating surface

should be insulated to help prevent heat loss and possible

freezing, particularly where pipes are run through roof

spaces and ventilated under floor spaces. Cisterns

situated in areas which may be exposed to freezing

conditions should also be insulated.

Draining taps must be located in accessible positions

which permit the draining of the whole system, including

the boiler and hot water storage vessel.

Draining taps should be at least

/2 inch nominal size. The

use of horizontal pipe runs should be avoided wherever

possible in order to prevent the collection of air in the

system. If horizontal runs are unavoidable, the pipes

should rise upwards in the direction away from the boiler.

Hot water systems should be in accordance with the

relevant recommendations.

Water Circulation System

(Models GCB and GEB only)

The cooker boiler should be connected to a cistern water

supply and subject to a maximum head of 18.25m and

minimum 1m.

The 28mm minimum diameter primary air flow pipe must

rise continuously from the cooker boiler to the cylinder to

ensure good gravity circulation and have an open vent.

The 28mm diameter primary flow return pipes must not

exceed 5.5m in length and be well insulated.

Water Connections

(Models GCB and GEB only)

The two 28mm copper flow and return pipes from the

boiler can be obtained for right or left hand connections.

Hot Water Storage Vessel

It is recommended that an indirect 190 litre (40 gallon) hot

water storage cylinder of the double feed type should be

lagged and fixed vertically as near as possible to the

cooker.

The water draw-off pipes to the taps must be dead leg

connection from the vent/expansion pipe.

A drain tap must be fitted at the lowest point of the

system.

THE HOT WATER SYSTEM