VOKERA Option Installation And Servicing Instructions

INTRODUCTION
The Vokèra Option is a combined central heating and
domestic hot water appliance. By design, it incorpo-
rates full sequence electronic ignition, circulating pump,
expansion vessel, safety valve, pressure gauge, and
mechanical timeclock.
The appliance is produced as a room sealed boiler,
suitable for wall mounted applications only. It is pro-
vided with a fan powered flue outlet with an annular co-
axial combustion air intake located on the top rear of the
appliance.
The appliance has been designed for use with a sealed
heating system, consequently it is not intended for use
with an open vented system.
2 4
2 3
2 2
2 1
2 0
1 9
1 8
1 7
1 6
1 5
Fig. 1
1
1 4 1 3
The appliance can be used in conjunction with an 'Y' or
'S' Plan system when stored hot water via an in-direct
cylinder is required.
An automatic range-rating facility is incorporated in the
boiler, which automatically adjusts boiler output to match
the current demand.
Domestic hot water is provided directly, via the bi-
thermic heat exchanger
2
Fig.1 General Layout
1 Flue Analysis Test Point
2 Pressure Tube Negative
3
3 Fan Assembly
4 Heat Exchanger
4
5 Secondary thermistor
6 Combustion chamber
5
7 Burner
8 Expansion vessel
6
9 Water pressure switch
10 Domestic Hot Water Flow Switch
11 Gas Valve
7
12 Mode selector switch
13 Fault indicator led
8 14 Timeclock
15 Low pressure indicator led
16 Pressure gauge
9
17 Safety valve
18 Pump
1 0
19 Auto air vent
1 1
20 Electrode
21 High limit thermistor
22 Primary thermistor
23 Air chamber (with cover removed)
24 Air pressure switch
25 Auto by pass (fig. 2)
26 Water flow restrictor (fig. 2)
1 2
1