VOKERA Rain24, Rain bi, Rain 28 Installation And Servicing Instructions
InstallationInstallation
InstallationInstallation
Installation
& Servicing& Servicing
& Servicing& Servicing
& Servicing
InstructionsInstructions
InstructionsInstructions
Instructions
THESE INSTRUCTIONS
TO BE RETAINED
BY USER
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Contents
Design principles and operating sequence Page
1.1 Principle components 2
1.2 Mode of operation 2
1.3 Safety devices 2
Technical data Page
2.1 Central heating 3
2.2 Gas pressure 3
2.3 Expansion vessel 3
2.4 Dimensions 3
2.5 Clearances 3
2.6 Connections 3
2.7 Electrical 3
2.8 Flue details 3
2.9 Emissions 3
2.10 Pump duty 4
General requirements Page
3A.1 Related documents 5
3A.2 Location of appliance 5
3A.3 Gas supply 5
3A.4 Flue system 5
3A.5 Air supply 5
3A.6 Water circulation 5
3A.6.1 Pipework 5
3A.6.2 Automatic by-pass 5
3A.6.3 Drain cocks 5
3A.6.4 Air release points 5
3A.6.5 Expans ion vessel 5
3A.6.6 Filling point 5
3A.6.7 Low pressure sealed system 6
3A.6.8 Frequent filling 6
3A.7 Electrical supply 6
3A.8 Mounting on a combustible surface 6
3A.9 Timber framed building 6
3A.10 Inhibitors 6
3A.11 Declaration of conformity 6
Installation Page
4.1 Delivery 7
4.1.2 RAIN application 7
4.1.3 RAIN bi application 7
4.2 Contents (appliance carton) 7
4.3.1 Unpacking 7
4.3.2 Preparation for mounting
the appliance (external application) 7
4.3.3 Important 7
4.4.1 External applications using the enclosure 7
4.4.2 External applications without the enclosure 8
4.5 Fitting the flue 8
4.5.1 Concentric horizontal flue 8
4.5.2 Concentric vertical flue 10
4.5.3 Vokera twin flue application 10
4.6 Connecting the gas and water 10
4.6.1 Gas 10
4.6.2 Flow and return 10
4.6.3 Safety valve 10
4.7 Electrical connections 10
4.8.1 Electrical connection 10
4.8.2 Connecting the mains (230V) input 10
4.7.1 Internal access 11
Commissioning Page
5.1 Gas supply installation 11
5.2 The heating system 11
5.3 Initial filling of the system 11
5.4 Initial flushing 11
5.5 Pre-operation checks 11
5.6 Initial lighting 11
5.7 Checking the burner pressure 11
5.8 Final flushing of the heating system 12
5.8.1 Inhibtors 12
5.9 Setting the boiler operating temperature 12
5.10 Setting the system design pressure 12
5.11 Regulating the central heating system 12
5.12 Final checks 12
5.13 Instructing the user 12
Servicing instructions Page
6.1 General 13
6.2 Routine annual servicing 13
6.3 Replacement of components 13
6.4 Component removal procedure 13
Checks, adjustments and fault finding page
7.1 Checking appliance operation 14
7.2 Appliance mode of operation 14
7.2.1 Selector switch in the OFF position 14
7.2.2 Selector switch in the ON position 14
7.2.3 Appliance functions 14
7.2.4 Heating mode 14
7.2.5 Heating parameters 15
7.3 Checking & adjusting burner pressure 15
7.3.1 Setting the maximum burner pressure 15
7.3.2 Setting the minimum burner pressure 15
7.4 Combustion analysis test 15
7.5 Checking the expansion vessel 16
7.6 External faults 16
7.6.1 Installation faults 16
7.7 Electrical checks 16
7.7.1 Earth continuity test 16
7.7.2 Short circuit check 16
7.7.3 Polarity check 16
7.7.4 Reversed polarity or supply fault 16
7.7.5 Resistance to earth check 17
7.8 Fault finding 17
7.8.1 Replacing the main PCB 17
7.9 Fault codes 17
Wiring diagrams Page
8.1 External wiring 18
8.2 Typical control applications 18
8.3 Room thermostat 18
8.4 Other controls 18
Functional diagram 19
Exploded diagrams Page
Table 1-5 21-24
L.P.G. instructions Page
10.1 Technical data 25
10.2 Converting the appliance gas supply 25
10.3 Gas supply installation 25
10.4 Checking & adjusting burner pressure 25
10.4.1 Setting the maximum burner pressure 25
10.4.2 Setting the minimum burner pressure 25
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INTRODUCTION
Fig.1/1A General Layout
1 Safety valve
2 Hydraulic manifold
3 Pressure switch
4 Pump
5 Auto air vent (AAV)
6 Main heat exchanger
7 High limit thermostat
8 Primary NTC sensor
9 Differential pressure switch
10 Flue outlet
11 Flue gas analysis test point
12 Silicone pressure tube (-)
13 Fan assembly
14 Expansion vessel
15 Combustion chamber
16 Main burner
17 Electrode
18 Transformer
19 Gas valve
20 Pressure gauge
21 Electrical connection box
22 Main switch
23 Led for working mode
24 Central heating control
The Vokera Rain & Rain bi appliances are central heating boilers, which - by design - incorporates electronic
ignition, circulating pump, expansion vessel, safety valve,
pressure gauge and automatic by-pass.
They are produced as category II2H3+ appliances, suitable for wall mounting applications only. They are provided with a fan powered flue outlet with an annular coaxial combustion air intake that can be rotated - horizontally - through 360 degrees for various horizontal or
vertical applications. The Rain & Rain bi appliances, can
also be used with the Vokera twin flue system.
These appliances are designed for use with a sealed
system only; consequently they are not intended for use
on open vented systems.
The provision of stored hot water is possible by the
addition of an indirect cylinder.
22 23 24
Fig. 1
Fig. 1A
Fig. 1B
Central heating
Gas
Return Flow
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SECTION 1 DESIGN PRINCIPLES AND OPERATING SEQUENCE
Fig. 2
1.1 PRINCIPLE COMPONENTS
● A fully integrated electronic control board fea-
turing electronic temperature control, anti-cycle control, pump over-run, self-diagnostic fault
indicator, continuous gas modulation.
● Low-water content copper heat exchanger.
● Electronic ignition with flame supervision.
● Integral pump.
● Fan.
● Expansion vessel.
● Differential air pressure switch.
● Water pressure switch.
● Two-stage gas valve.
● Pressure gauge.
● Safety valve.
1.2 MODE OF OPERATION
When there is a request for heat and/or hot water
via the programmer/time clock and/or any external control, the pump and fan are started, the fan
proves the differential air pressure switch which
in-turn allows an ignition sequence to begin.
Ignition is sensed by the electronic circuitry to
ensure flame stability at the burner. Once successful ignition has been achieved, the electronic
circuitry increases the gas rate to 75% for a
period of 15 minutes. Thereafter, the boiler’s
output will either be increase to maximum or
modulate to suit the set requirement.
When the appliance reaches the desired temperature the burner will shut down and the boiler
will perform a three-minute anti-cycle (timer delay).
When the request for heat and/or hot water has
been satisfied the appliance pump and fan may
continue to operate to dissipate any residual heat
within the appliance.
1.3 SAFETY DEVICES
When the appliance is in use, safe operation is
ensured by:
● A water pressure switch that monitors system
water pressure and will de-activate the pump,
fan and burner should the system water pressure drop below the rated tolerance.
● A high limit thermostat that over-rides the tem-
perature control circuit to prevent or interrupt
the operation of the burner.
● A differential air pressure switch that checks
the operation of the fan and flue thereby allowing safe operation of the burner.
● A safety valve which releases excess pressure
from the primary circuit.
CH
returnCHflow
automatic
by-pass
flue outlet air intake
pressure
switch
main heat
exchanger
CH water drain tap
main
burner
gas valve
pressure
switch
safety
valve
pump
bottom
AAV
expansion
vessel
primary
NTC sensor
fan
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SECTION 2 TECHNICAL DATA
Ref. Condition 15 °C , 1013,25 mbar, dry gas
NOTE: L.P.G. data refer to section 10
2.1 Central heating
Heat input (kW) 26.3 30.5
Heat output (max) 24.0 27.6
Heat output (min) 9.4 10.5
Minimum working pressure 0.5 bar
Maximum working pressure 3.0 bar
Minimum flow rate 350 l/h
2.2 Gas pressures
Inlet pressure G20 20.0 mbar
Maximum burner pressure 10.1 mbar 11.3 mbar
Minimum burner pressure 1.9 mbar 2.25 mbar
Gas rate 2.78 m3/h 3.23 m3/h
Injectors size 12 x 1.35 mm 13 x 1.35 mm
2.3 Expansion vessel
Capacity 8 litres
Maximum system volume 91 litres
Pre-charge pressure 1.0 bar
2.4 Dimensions
Height 810 mm (1223 box) 810 mm (1223 box)
Width 450 mm (654 box) 450 mm (654 box)
Depth 250 mm (257box) 250 mm (257box)
Dry weight 35 kg - 31 kg 35 kg - 31 kg
2.5 Clearances
Sides 12 mm
Top 150 mm from casing or 25 mm above flue elbow, whichever is applicable
Bottom 150 mm
Front 600 mm
2.6 Connections
Flow & return 22 mm (compression)
Gas 15 mm (compression)
Safety valve 15 mm copper
2.7 Electrical
Voltage 230V/~ 50hz
Power consumption 125 W
Internal fuse 2 AL
External fuse 3 A
2.8 Flue details (concentric)
Maximum horizontal flue length (concentric) 1.0 m 1.0 m
Maximum vertical flue length (concentric) 1.0 m 1.0 m
Maximum twin flue length (horizontal ir vertical) 20m/20m + terminal 14,5m/14,5m + terminal
2.9 Emissions
NOx (max-min) PPM 140 - 110 140 - 110
CO (max-min) PPM 100 - 130 80 - 150
CO2 (max-min) % 6.95 - 2.60 6.80 - 2.60
CO/CO2 ratio (max) 0.0014 to 1 0.0011 to 1
CO/CO
2
ratio (min) 0.005 to 1 0.0057 to 1
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2.10 PUMP DUTY
Fig. 3 shows the flow-rate available - after
allowing for pressure loss through the appliance - against system pressure loss. When
using this graph apply only the pressure loss
of the system. The graph is based on a 20 ºC
temperature differential.
Fig. 4
SECTION 3 GENERAL REQUIREMENTS
Key Location Minimum distance
A Below an opening (window, air-brick, etc.) 300 mm
B Above an opening (window, air-brick, etc.) 300 mm
C To the side of an opening (window, air-brick, etc.) 300 mm
D Below gutter, drain-pipe, etc. 75 mm
E Below eaves 200 mm
F Below balcony, car-port roof, etc. 200 mm
G To the side of a soil/drain-pipe, etc. 150 mm
H From internal/external corner or boundary 300 mm
I Above ground, roof, or balcony level 300 mm
J From a surface or boundary facing the terminal 600 mm
K From a terminal facing a terminal 1200 mm
L From an opening in the car-port into the building 1200 mm
M Vertically from a terminal on the same wall 1500 mm
N Horizontally from a terminal on the same wall 300 mm
P From a structure to the side of the vertical terminal 300 mm
Q From the top of the vertical terminal to the roof flashing As determined by the fixed collar
of the vertical terminal
Fig. 3
Water pressure (mbar)
Litres Per Hour (x100)
100
200
300
400
500
600
0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400
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This appliance must be installed by a competent
person in accordance with and defined by, the
Standard Specification (Domestic Gas Installations) Declaration (I.S. 813).
3A.1 RELATED DOCUMENTS
The installation of this boiler must be in accordance with the relevant requirements of the local
building regulations, the current ETCI National
Rules for Electrical Installations, and the bylaws
of the local water undertaking.
It should be in accordance also with any relevant
requirements of the local and/or district authority.
3A.2 LOCATION OF APPLIANCE
The appliance may be installed in any room or
internal space, although particular attention is
drawn to the requirements of the current ETCI
National Rules for Electrical Installations, and I.S.
813, Annex K.
When an appliance is installed in a room or internal space containing a bath or shower, the
appliance or any control pertaining to it must not
be within reach of a person using the bath or
shower. The location chosen for the appliance
must permit the provision of a safe and satisfactory flue and termination. The location must also
permit an adequate air supply for combustion purposes and an adequate space for servicing and
air circulation around the appliance. Where the
installation of the appliance will be in an unusual
location special procedures may be necessary,
refer to I.S. 813 for detailed guidance on this
aspect. A compartment used to enclose the
appliance must be designed and constructed
specifically for this purpose. An existing
compartment/cupboard may be utilised provided
that it is modified to suit.
The appliance can be installed external to a property or dwelling provide the installation has been
carried out in accordance with these instructions
and the provisions of I.S. 813.
3A.3 GAS SUPPLY
The gas meter - as supplied by the gas supplier
- must be checked to ensure that it is of adequate
size to deal with the maximum rated input of all
the appliances that it serves. Installation pipes
must be fitted in accordance with I.S. 813. Pipe
work from the meter to the appliance must be of
adequate size. Pipes of a smaller size than the
appliance gas inlet connection must not be used.
The installation must be tested for soundness in
accordance with I.S. 813. If the gas supply serves
more than one appliance, it must be ensured that
an adequate supply is maintained to each appliance when they are in use at the same time.
3A.4 FLUE SYSTEM
The terminal should be located where the dispersal of combustion products is not impeded and
with due regard for the damage and discoloration
that may occur to building products located nearby.
The terminal must not be located in a place where
it is likely to cause a nuisance (see I.S. 813). In
cold and/or humid weather, water vapour may
condense on leaving the terminal; the effect of
such pluming must be considered. If installed
less than 2m above a pavement or platform to
which people have access (including balconies or
flat roofs) the terminal must be protected by a
guard of durable material. The guard must be
fitted centrally over the terminal. Refer to I.S.
813, when the terminal is 0.5 metres (or less)
below plastic guttering or 1 metre (or less) below
painted eaves.
3A.5 AIR SUPPLY
The following notes are intended for general
guidance only.
This appliance is a fan-flued boiler, approved for
use with certain Type ‘B’ and Type ‘C’ applications. Consequently it may require a permanent
air vent for combustion air supply.
Guidance on the requirements for combustion air
and instructions for Type B22 applications can be
found in Section 4.
3A.6 WATER CIRCULATION
Specific recommendations are given in I.S. 813.
The following notes are for general guidance only.
3A.6.1 PIPEWORK
It is recommended that copper tubing be used in
conjunction with soldered capillary joints.
Where possible pipes should have a gradient to
ensure air is carried naturally to air release points
and that water flows naturally to drain cocks.
Except where providing useful heat, pipes should
be insulated to avoid heat loss and in particular to
avoid the possibility of freezing. Particular attention should be paid to pipes passing through
ventilated areas such as under floors, loft space,
and void areas.
3A.6.2 AUTOMATIC BY-PASS
The appliance has a built-in automatic by-pass.
However it may be necessary to fit an external
bypass should the design of the heating system
require such. In any case, the design of the
system should be such that it prevents boiler
‘cycling’.
3A.6.3 DRAIN COCKS
These must be located in accessible positions to
facilitate draining of the appliance and all water
pipes connected to the appliance.
3A.6.4 AIR RELEASE POINTS
These must be positioned at the highest points in
the system where air is likely to be trapped. They
should be used to expel trapped air and allow
complete filling of the system.
3A.6.5 EXPANSION VESSEL
The appliance has an integral expansion vessel
to accommodate the increased volume of water
when the system is heated. It can accept up to 8
litres of expansion from within the system, generally this is sufficient, however if the system has an
unusually high water content, it may be necessary to provide additional expansion capacity
(see 6.19).
3A.6.6 FILLING POINT
An approved method for initial filling of the system
and replacing water lost during servicing etc. is
required (see fig. 5). This method of filling must
comply with local water regulations and/or I.S.
813.
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3A.6.7 LOW PRESSURE SEALED SYSTEM
An alternative method of filling the system would
be from an independent make-up vessel or tank
mounted in a position at least 1-metre above the
highest point in the system and at least 5-metres
above the boiler (see fig. 5A).
The cold feed from the make-up vessel or tank
must be fitted with an approved non-return valve
and stopcock for isolation purposes. The feed
pipe should be connected to the return pipe as
close to the boiler as possible.
3A.6.8 FREQUENT FILLING
Frequent filling or venting of the system may be
indicative of a leak. Care should be taken during
the installation of the appliance to ensure all
aspects of the system are capable of withstanding pressures up to at least 3 bar.
3A.7 ELECTRICAL SUPPLY
The appliance is supplied for operation on 230V @
50Hz electrical supply; it must be protected with a
3-amp fuse. The method of connection to the
mains electricity supply must allow for complete
isolation from the supply. The preferred method is
by using a double-pole switch with a contact separation of at least 3mm. The switch must only supply
the appliance and its corresponding controls, i.e.
time clock, room thermostat, etc.
3A.8 MOUNTING ON A COMBUSTIBLE SURFACE
If the appliance is to be fitted on a wall of
combustible material, a sheet of fireproof material must protect the wall.
3A.9 TIMBER FRAMED BUILDINGS
If the appliance is to be fitted in a timber framed
building, it should be fitted in accordance with I.S.
813 and local Building Regulations.
The Institute of Gas Engineers publication (IGE/
UP/7) ‘Guide for Gas Installations in Timber
Frame Buildings’ gives specific advice on this
type of installation.
3A.10 INHIBITORS
Vokera recommend that an inhibitor - suitable for
use with copper heat exchangers - is used to
protect the boiler and system from the effects of
corrosion and/or electrolytic action. The inhibitor
must be administered in strict accordance with
the manufacturers instructions*.
*Water treatment of the complete heating system
- including the boiler - should be carried out in
accordance with I.S. 813 and the Domestic Water
Treatment Association’s (DWTA) code of practice.
3A.11 DECLARATION OF CONFORMITY
A Declaration of Conformity (as defined in I.S.
813) must be provided on completion of the installation.
A copy of the declaration must be given to the
responsible person and also to the gas supplier if
required.
Fig. 5a
Make-up vessel
or tank
Automatic
air-vent
Non-return
valve
Stopcock
5.0 metres minimum
Heating
return
Fig. 5
control valve
temporary
connection
control valve
supply pipe
double check
valve
flow/return pipe
Fig. 6
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SECTION 4 INSTALLATION
Fig. 7External
installation
Internal
installation
Fig. 7ARain bi Boiler
4.1 DELIVERY
Due to the weight of the appliance it may be
necessary for two people to lift and attach the
appliance to its mounting. The appliance is
contained within a heavy-duty cardboard carton. Lay the carton on the floor with the writing
the correct way up. The appliance enclosure (if
required) is also supplied within a heavy-duty
cardboard carton.
4.1.2 RAIN APPLICATION
The ‘Rain’ can be installed within the property or
external to the property. Although the appliance
is certified IPx5D, if it’s to be installed externally,
it may be necessary to use the rain-cover (not
supplied) and provide reasonable protection from
heavy or persistent rain (see fig. 7). Alternatively,
the appliance enclosure (see figs. 1 & 7A) can be
used (not supplied).
4.1.3 RAIN bi APPLICATION
The ‘Rain bi’ must be installed within the purpose
made enclosure (not supplied) see figs. 1 & 7A.
4.2 CONTENTS (appliance carton)
Contained within the carton is:
● the appliance
● the documentation
● service valves & accessories
● flue restrictors
● appliance template
● appliance wall bracket.
4.3.1 UNPACKING
At the top of the carton pull both sides open - do
not use a knife - unfold the rest of the carton from
around the appliance, carefully remove all protective packaging from the appliance, and lay the
accessories etc. to one side. Protective gloves
should be used to lift the appliance, the appliance
back-frame should be used for lifting points.
4.3.2 PREPARATION FOR MOUNTING THE APPLIANCE (external application)
The appliance and/or the appliance enclosure
should be mounted on a smooth, vertical, noncombustible surface, which must be capable of
supporting the full weight of the appliance and/or
enclosure. Care should be exercised when determining the position of the appliance with respect
to hidden obstructions such as pipes, cables, etc.
When the position of the appliance has been
decided - using the template supplied - carefully
mark the position of the wall-mounting bracket
(see fig. 6) and flue-hole (if applicable).
4.3.3 IMPORTANT
The Rain/Rain bi can be used on various
applications (4.1.2). The following instructions relate to external applications, i.e. external to the property or dwelling.
4.4.1 EXTERNAL APPLICATIONS USING THE ENCLOSURE
Both the Rain and Rain bi boilers can be used with
the enclosure. The Enclosure has been designed
to be recessed into an external wall or surface to
give a flush finish. It can however, be mounted
onto an external wall if required.
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