Ferroli Optima 901 Installation Instructions Manual page 3

Wall mounted, room sealed, fan assisted, gas combination boiler

Table of Contents

General Description

The Ferroli

901 is a wall mounted, room sealed, fan assisted, combination boiler for Central Heating

(C.H.) and domestic Hot Water (D.H.W.).

The boiler is of light weight construction and the heat exchanger provides Central Heating and Domestic

Hot Water from an integrally designed unit. The boiler contains its own expansion vessel for sealed systems.

The wall mounting jig contains all the isolating cocks for the water and gas supplies which can be fitted to

the wall and provided with all the necessary gas and water connections prior to the boiler being attached.

The flue can either be left hand, right hand or rear. There are three flue lengths available and they are 0.75

metres (for wall thickness up to 565 mm), 2 metres (for wall thickness up to 1815 mm) and 3 metres (for wall

thickness up to 2815 mm). These wall thicknesses assume a rear flue aoutlet. For side flue outlet the effective

wall thickness for each flue length is reduced by 91 mm plus the distance of the appliance from the side wall.

The Central Heating and the Domestic Hot Water temperature is controlled by the Honeywell Modureg valve

in conjunction with the P.C.B. The boiler is fitted with its own Central Heating pump. The pump is switched

ON/OFF by the time clock and/or a 24 Volt room thermostat. The pump circuit also has a 6 minute over-run

time. There is a Domestic Hot Water flow switch fitted and when there is a demand for Domestic Hot

Water (flow of more than 0.5 gallon/minute, 2.5 litre/minute) the Central Heating pump is switched off

making available the maximum output of the gas burner for Domestic Hot Water. On the P.C.B. the output

for Central Heating can be set. However, this is not required for the majorities of installations as the boiler

will automatically adjust its output to the system demand-AUTO-MISER control. This does not influence the

maximum output for domestic hot water. The appliance is not suitable for external installation.

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Optima 701