Grant VORTEX Pro Combi Series, VORTEX Pro Combi 21e, VORTEX Pro Combi 26e, VORTEX Pro Combi 36e Installation & Servicing Instructions Manual
Grant VORTEX Pro Internal Combi
Combi 21e, Combi 26e and Combi 36e Condensing Oil Boiler Range
Installation & Servicing Instructions
Part No. DOC 88. Rev 00. May 2012
Commissioning Report
2
Commissioning
Report
GRANT ENGINEERING (UK) LIMITED
Hopton House, Hopton Industrial Estate, Devizes, Wiltshire SN10 2EU
Tel: 01380 736920 Fax: 01380 736991
Email: sales@grantuk.com www.grantuk.com
This manual is accurate at the date of printing but will be superseded and should be disregarded if specifications and/or
appearances are changed in the interests of continued product improvement.
All good sold are subject to our official Conditions of Sale, a copy of which may be obtained on application.
© Grant Engineering (UK) Limited 2012. No part of this manual may be reproduced by any means without prior written consent.
For use with Kerosene* only.
After installing the boiler leave these
instructions with the User.
This appliance is deemed a controlled
service and specific regional statutory
requirements may be applicable.
*Operation on Bio-fuel
All Grant Vortex Pro condensing boilers,
manufactured since May 2011, are
suitable for operation on both standard
kerosene (Class C2 to BS2869) and
also bio-kerosene – up to a 30% blend
(B30K).
All burner settings and nozzle sizes (as
detailed in Section 2.3 of this manual)
are correct for both standard kerosene
and bio-kerosene (B30K).
In order to operate this boiler on
bio-kerosene it will be necessary to
take the following actions:
a) Use a bio-kerosene (B30K)
compatible flexible oil line in place of
the oil line supplied with this boiler.
b) Have your oil storage tank and oil
supply line (including all pipework, sight
gauges, filters, isolating valves, fire
valves, de-aeration devices, etc.)
checked for their compatibility with
bio-kerosene (B30K).
Where necessary some, or all, of these
items may have to be replaced with a
bio-kerosene compatible alternative.
c) Check the suitability of the flue
system with Grant UK.
d) Use only bio-kerosene (B30K) that
conforms to OPS24.
IMPORTANT
Under no circumstances should the
boiler be used with bio-kerosene
without the above actions being taken
first.
Date:
Commissioning engineer:
Tel. No:
Boiler model: Boiler output: kW
Fuel type: Kerosene
Nozzle size: Pump pressure:
Air setting: Flue gas % CO
2
:
Net flue gas temp: Smoke No:
System flushed: Yes / No
Corrosion inhibitor added: Yes / No
Antifreeze added: Yes / No
(where there is a Yes / No - please circle appropriate answer)
For sealed systems only:
Expansion vessel size : litres
Expansion vessel change pressure : bar
Sealed system fill pressure (cold) : bar
Service Log
It is recommended that the boiler should be regularly serviced, at least once a year,
and the details entered in the Boiler Handbook by the service engineer.
Contents
Contents
3
1 Introduction 4
1.1 How a Condensing Boiler Works 4
1.2 Boiler Description 4
1.3 Boiler Components 5
2 Technical Data 6
2.1 Boiler Technical Data 6
2.2 Burner Settings 7
2.3 Vortex Combi e Boilers using
Class C2 Kerosene 7
2.4 Flue Gas Analysis 7
2.5 Boiler Dimensions 8
3 Oil Storage & Supply System 10
3.1 Fuel Supply 10
3.2 Burner Oil Connection 13
4 Boiler Installation Information 14
4.1 Introduction 14
4.2 Boiler Location 14
4.3 Preparation for Installation 14
4.4 Installing the Boiler 14
4.5 Expansion Vessel 14
4.6 Filling and Venting the System 14
4.7 Regulations Compliance Requirements 15
4.8 Completion 15
4.9 Before you Commission 15
4.10 Underfloor Heating Systems 15
4.11 Pipework Materials 15
4.12 Sealed Systems 15
4.13 Underfloor Pipework 15
5 Pipe Connections 16
5.1 Water Connections 16
5.2 Making the Water Connections 16
5.3 Domestic Hot Water System 17
5.4 To use the Water Hardness Kit 17
6 Condensate Disposal 18
6.1 General Requirements 19
6.2 Connections 18
6.3 Pipework 18
6.4 External Pipework 18
6.5 Condensate Soakaway 18
6.6 Condensate Trap 19
6.7 Condensate Disposal Pipework 19
6.8 Inspection and Cleaning of Trap 19
6.9 External Condensate Trap Fitting 19
7 Sealed Systems 21
7.1 System Models 21
8 Electrical 22
8.1 Connecting the Power Supply 22
8.2 Connecting the Controls - Heating Only 24
8.3 Connecting the Controls - Heating
and Hot Water 28
8.4 Connecting an External Frost Thermostat 31
9 Flue System & Air Supply 32
9.1 Air Supply 32
9.2 Conventional Flue Systems 33
9.3 Connecting a Conventional Flue 35
9.4 Balanced Flue Systems 35
9.5 Prepare the Wall 39
9.6 High Level and Vertical Balanced Flue 39
10 Commissioning 40
10.1 Boiler Controls 41
10.2 Commissioning the Vortex Pro
Combi 21e Riello RDB Burner 41
10.3 Information for the User 42
10.4 Balancing the System 42
10.5 Completion 42
10.6 Air Adjuster Disc - Combi 21 only 43
10.7 Information for the User 43
11 Boiler Servicing 44
11.1 Checking before Servicing 44
11.2 Dismantling Prior to Servicing 44
11.3 Cleaning the Boiler 44
11.4 Cleaning the Burner 46
12 Fault Finding 47
12.1 Initial Checklist - for Installer or
Service Engineers 47
12.2 Main Fault Finding Procedures 48
12.3 Poor Hot Water Checklist 51
12.4 Riello RDB Burner Fault Finding 52
13 Spare Parts 53
14 Health & Safety Information 55
14.1 Insulation Materials 55
14.2 Insulation Materials 55
14.3 Kerosene and Gas Oil Fuels (mineral oils) 55
15 EC Declaration of Conformity 56
16 Warranty 56
16.1 The Vortex Oil Boiler Warranty 56
16.2 Extended Warranty 57
1 Introduction
4
Introduction
Warning of possible human injury as
a consequence of not following the
instructions in the warning.
To ensure maximum efficiency, the boiler
return temperature should be 55° C or
less, this will enable the latent heat to be
condensed out of the flue gases.
The boiler will achieve net thermal
efficiencies of 100%.
To achieve maximum performance from
the Grant VORTEX Pro Combi e boilers,
it is recommended that the heating
system is designed so that a
temperature differential of 20° C
between the flow and return is
maintained.
The Vortex Pro Combi e boilers will
however still operate at extremely high
efficiencies even when it is not in
condensing mode and therefore is
suitable for fitting to an existing heating
system without alteration to the radiator
sizes. The boiler is capable of a
maximum flow temperature of 78° C.
1.2 Boiler Description
The Vortex Pro Combi e boilers are
automatic pressure jet oil boilers
designed for use with a sealed central
heating system and will provide
domestic hot water at mains pressure.
All boilers are supplied with the control
panel and burner factory fitted.
All boilers can be connected to either a
conventional flue system or a balanced
flue system, as required.
The boilers are suitable for use in sealed
central heating systems only.
All models are supplied with the control
panel and burner factory fitted. The
boilers can be connected to either a
conventional flue system or a balanced
flue system, as required.
For Conventional Flue Applications
Where a chimney is to be lined - Grant
recommends the use of the Grant
‘Orange’ flue system, specifically
designed for the Vortex range of
condensing boilers. Refer to Section 9.2
for further details.
Caution concerning likely damage to
equipment or tools as a
consequence of not following the
instructions in the caution.
The flue system materials and
construction MUST be suitable for
use with oil-fired condensing boilers.
Failure to fit a suitable conventional
flue may invalidate the warranty on
the boiler.
For Balanced Flue Applications
The following flue kits are available from
Grant UK.
Refer to Section 9 for further details.
Yellow System
Standard low level concentric balanced
flue - components available:
•
Low level concentric balanced flue
short
•
Extensions 225mm, 450mm and
675mm
•
90° extension elbow
•
45° extension elbow
•
45° elbow
• Plume Diverter Kit
Green System
Standard external high level/vertical flue
starter kit (room sealed) - components
available:
• External high level/vertical flue
starter kit short (room sealed)
• Extensions 150mm, 250mm,
450mm, 950mm and adjustable
195 to 270mm
• 45° elbow
• High level terminal
• Vertical terminal
Note text. Used for emphasis or
information not directly concerned
with the surrounding text but of
importance to the reader.
1.1 How a Condensing
Boiler Works
During the combustion process,
hydrogen and oxygen combine to
produce heat and water vapour. The
water vapour produced is in the form of
superheated steam in the heat
exchanger. This superheated steam
contains sensible heat (available heat)
and latent heat (heat locked up in the
flue gas). A conventional boiler cannot
recover any of the latent heat and this
energy is lost to the atmosphere
through the flue.
The Grant VORTEX Pro Combi
condensing boilers contain an extra
heat exchanger which is designed to
recover the latent heat normally lost by
a conventional boiler. It does this by
cooling the flue gases to below 90° C,
thus extracting more sensible heat and
some of the latent heat. This is achieved
by cooling the flue gases to their dew
point (approximately 55° C).
!
WARNING
!
CAUTION
!
NOTE
!
NOTE
Where a rigid conventional flue - internal
to external - is required, Grant
recommends the use of a hybrid system
consisting of Grant 'Green' and
'Orange' flue system components. As
no flue adaptor is supplied with the
boiler it will be necessary to purchase
the Grant CF adaptor kit to connect this
system to the boiler correctly.
Flue adaptor kit - Ref. CFA15/70 - is
used for all models as they all use the
100mm 'Green' and 'Orange' system
components to construct a flue of
maximum vertical height 8 metres.
This manual is intended to guide
engineers in the installation and
maintenance of Grant Pro Internal
Combi e boilers. A separate manual
is available to guide users in the
operation of these boilers, and is
printed inverted at the end of this
manual.
The following special text formats are
used in this manual for the purposes
listed below:
Introduction
5
White System
High level concentric balanced flue kit components available:
• Vertical concentric balanced flue kit.
• Extensions 225mm, 450mm,
950mm and adjustable 275 to
450mm.
• 45° elbow.
Red System (for Combi 21e and 26e
only)
A flexible vertical balanced flue system
designed to be fitted inside an existing
masonry chimney.
Consisting of three sections:
• Concentric white painted flue pipe
connected to the boiler.
• Vertical concentric flexible flue
(flexible stainless steel flue liner
inside a flexible plastic air inlet liner).
• Terminal assembly for chimney top
mounting.
Flue extensions and 45° elbows from the
White system may be used.
Fitting instructions for the Low level,
High level and Vertical balanced flue
systems are supplied with the kits.
1.3 Boiler Components
The Vortex Pro Combi e boilers are only
suitable for use with Kerosene.
All burners are ready to connect to a
single pipe system with a loose flexible
fuel line (900mm) and
3
/8" to 1/4" BSP
male adaptor supplied with the boiler. If
required, an additional flexible fuel line
(900mm) and
3
/8" to 1/4" BSP male
adaptor are available to purchase from
Grant Engineering (UK) Limited, for
two-pipe oil supply system, Part No.
RBS36.
The temperature of the water leaving
the boiler to heat the radiators is User
adjustable.
The setting of the boiler thermostat on
the Vortex Pro Combi boilers has no
effect on the hot water performance.
The boiler is fitted with an overheat
thermostat (which allows it to be used
on a sealed central heating system)
which will automatically switch off the
boiler if the heat exchanger exceeds a
pre-set temperature of 111°C ± 3°C.
Figure 1-1 shows the components in
the Vortex Pro Combi e boilers and the
position of the control panel. Figure 1-2
shows the details of the control panel.
The control panel is fitted with an ON/OFF switch, Heating switch, Hot
water switch, Indicator lights, Boiler (heating), Pressure gauge and
manual reset button for the overheat thermostat.
Figure 1-1: Vortex Pro Combi e boiler with front panel removed
Figure 1-2: Vortex Pro Combi e boiler control panel
Heating (CH)
pump
Hot water (DHW) pump
Plug-in
programmer
position
(if fitted)
Heating
switch
Hot water
switch
Boiler
thermostat
Over heat
reset
button
(under
black cap)
Boiler
On / Off
switch
Indicator
lights
Pressure
gauge
Non return
valve
Non return
valve
Expansion vessel
Condensate trap
Burner lock-out button
2 Technical Data
6
2.1 Boiler Technical Data
Vortex Pro Combi Vortex Pro Combi Vortex Pro Combi
Model 21e 26e 36e
Boiler water content Litres 48.0 48.5 53.5
(including 32 litre primary store) Gal 10.6 10.7 11.8
Weight (dry)* kg 146 188 218
lbs 322 415 481
Connections: Heating flow and return mm 22 22 28
Cold water mains inlet mm 15 15 22
Domestic hot water outlet mm 15 15 22
Pressure relief valve discharge mm 15
Condensate connection 22mm plastic pipe
Flue size (conventional) 100 mm (4 in) diameter
Waterside resistance Flow/Return temp.
diff. of 10°C
mbar 28.5 26.0
Waterside resistance Flow/Return temp.
diff. of 20°C
mbar 10.0 9.5
Boiler thermostat range °C 65 to 78
Limit (safety) thermostat switch off temp. °C 111°C +0 -3
Maximum heating system pressure (cold) bar 1.0
Minimum heating system pressure (cold) bar 0.5
Pressure relief valve bar 2.5
Expansion vessel (pre-charged at 1 bar) litres 10 12 14
Maximum heating system volume** litres 106 128 148
Maximum operating pressure bar 2.5
Minimum domestic hot water flow rate 3.0 litres/min (0.66 gal/min)
Maximum domestic hot water temperature °C 65 (factory set)
Maximum mains water inlet pressure bar 8.0
Minimum recommended mains water
inlet pressure
bar 2.5
Maximum hearth temperature °C Less than 50
Electricity supply 230V ~ 50Hz Fused at 5 Amp
Motor power 90 W max.
Starting current Amp 4.2 2.60
Running current Amp 0.85
Oil connection
1
/4" Male BSP (on end of flexible fuel line)
Conventional flue Minimum flue draught - 8.7 N/m² (0.035 in wg)
Maximum flue draught - 37 N/m² (0.15 in wg)
* Weight includes burner but excludes flue
** Based on expansion vessel charge and initial cold system pressure of 0.5 bar
Technical Data
Technical Data
7
Heat
SEDBUK
Nozzle Oil Smoke Burner Fuel Flue gas CO
2
output
SAP 2009
pressure
number head flow temp
Model Burner type kW Btu/h
%
bar kg/h °C %
21e Riello RDB 2.2 21.0 71,650 89.5 0.60/80ºEH 9.0 0-1 T1 1.83
80 (flue)
12
235 (door)
26e Riello RDB 1 26.0 88,700 90.2 0.75/80ºEH 8.0 0-1 T2 2.16 75 - 80 12
36e Riello RDB 2.2 36.0 123,000 91.6 1.00/80ºEH 9.1 0-1 T5 3.01 78 12
2.2 Burner Settings
Burners are supplied factory set at
the outputs shown.
When commissioning, the air damper
must be adjusted to obtain the
correct CO
2
level and the Installer
must amend the data label.
2.3 Vortex Combi e Boilers using Class C2 Kerosene
Vortex Combi e boilers are only for
use with kerosene.
!
NOTE
!
NOTE
The data given below is approximate
only and is based on the boiler being
used with a low level balanced flue.
The above settings may have to be
adjusted on site for the correct
operation of the burner.
Gas Oil is not suitable for use with a
Grant Vortex Pro Combi e boiler.
The net flue gas temperatures given
above are ± 10%.
When commissioning the air damper
must be adjusted to obtain the correct
CO
2
level.
The combustion door test point may be
used for CO
2
and smoke readings only.
Do not use this test point for
temperature or efficiency readings.
2.4 Flue Gas Analysis
To allow the boiler to be commissioned
and serviced, the boiler is supplied with
a combustion test point on the front
cleaning door. When this test point is
used please note the following:
• The test point is for CO
2
and smoke
readings only.
• The boiler efficiency and
temperature must be taken from the
flue test point on high level, vertical
and conventional flue adaptors.
• Concentric low level flues do not
contain a test point. The temperature
and efficiency readings must be
taken from the flue terminal.
8
Technical Data
Figure 2-1: Vortex Pro Combi Internal 21e and 26e dimensions
2.5 Boiler Dimensions
All dimensions in the diagram above are in millimetres.
2 Technical Data
Right Side View
Plan View
Left Side View
Rear View
External drain trap
exit (left hand)
Internal drain trap
exit (left hand)
high level
Internal drain trap
exit (left hand)
low level
108
227
441
19
98
35
190190 210
62
90
62
90
15
ø155
ø31
590
295
140
125
697
587
142
98
860
691
Technical Data
9
Figure 2-2: Vortex Pro Combi 36e dimensions
All dimensions in the diagram above are in millimetres.
Right Side ViewLeft Side View
External drain trap
exit (left hand)
Internal drain trap
exit (left hand)
high level
Internal drain trap exit
(left hand) low level
190
60
14
Rear View
182.5182.5 250
62
90
615
554
170
694.5
170
695
900
456
82
86
307.5
Plan View
101
605
ø185
ø31
ø31
10
Oil Storage &
Supply System
3.1 Fuel Supply
Fuel Storage
The tank should be positioned in
accordance with the recommendations
given in BS 5410:1:1997, which gives
details of filling, maintenance and
protection from fire.
A steel tank may be used and must be
constructed to BS 799:5:1987 and OFS
T200.
A galvanised tank must NOT be used.
A plastic tank may be used and must
comply with OFS T100.
Plastic tanks should be adequately
and uniformly supported on a
smooth level surface, across their
entire load bearing base area, that is,
the area in contact with the ground.
Fuel Pipes
For gravity fuel supply systems, fuel
supply pipes should be of copper tubing
with an external diameter of at least
10 mm.
Flexible pipes must NOT be used
outside the boiler case.
A remote sensing fire valve must be
installed in the fuel supply line (outside)
where it enters the building, with the
sensing head located above the burner.
Recommendations are given in
BS 5410:1:1997.
A metal bowl type filter with a
replaceable micronic filter must be fitted
in the fuel supply line adjacent to the
boiler. A shut-off valve should be fitted
before the filter, to allow the filter to be
serviced.
A flexible fuel line, adaptor and
1
/4" BSP
isolation valve are supplied loose with
the boiler for the final connection to the
burner. If a two pipe system or Tiger
Loop system is used, an additional
flexible fuel line (900mm) and
3
/8" to 1/4"
BSP male adaptor are available from
Grant Engineering (UK) Limited (Part No.
RBS36).
Metal braided flexible pipes should be
replaced annually when the boiler is
serviced. Long life flexible pipes should
be inspected annually and replaced at
least every 60 months.
!
CAUTION
!
CAUTION
Galvanised pipe must not be used.
All pipe connections should preferably
use flared fittings. Soldered connections
must not be used on oil pipes.
!
CAUTION
!
NOTE
Grant UK recommend that a fire valve
with a temperature rating of 95°C be
installed on any Grant Vortex Pro
Combi.
!
NOTE
3 Oil Storage & Supply System
Oil Storage &
Supply System
11
Single Pipe System
Where the storage tank outlet is above
the burner the single pipe system
should be used. The height of the tank
above the burner limits the length of
pipe run from the tank to the burner.
As supplied the burner is suitable for a
single pipe system.
Head A Max Pipe Length (m)
(m) ø 8mm ø 10mm
0.5 10 20
12040
1.5 40 80
2 60 100
Figure 3-1: Single pipe system
Two Pipe System
With the storage tank outlet below the
burner, a two pipe system should be
used. The pipe runs should
be as shown in Figure 3-2. The return
pipe should be at the same level in the
tank as the supply pipe,
both being 75 to 100 mm above the
base of the tank. The pipe ends should
be a sufficient distance apart
so as to prevent any sediment disturbed
by the return entering the supply pipe.
Avoid the bottom of the tank being
more than 3.5m below the burner.
A non-return valve should be fitted in
the supply pipe together with the filter
and fire valve. A non return valve should
be fitted in the return pipe if the top of
the tank is above the burner.
The pump vacuum should not exceed
0.4 bar. Beyond this limit gas is released
from the oil.
For guidance on installation of top
outlet fuel tanks and suction oil
supply sizing, see OFTEC technical
book 3.
Available at www.oftec.org.uk.
Figure 3-2: Two pipe system
Head A Max Pipe Length (m)
(m) ø 8mm ø 10mm
0 35 100
0.5 30 100
1 25 100
1.5 20 90
21570
3830
3.5 6 20
Fire
valve
Fire valve sensor
Vent pipe
Fill pipe
Sludge
valve
Shut-off
valve
Shut-off
valve
Level
gauge
Filter
Fuel
storage
tank
Pump (see section 3.2)
Pump (see section 3.2)
Fire
valve
Fire
valve
sensor
Vent
pipe
Fill
pipe
Sludge
valve
Shut-off
valve
Shut-off
valve
Shut-off valve
Level gauge
Non
return
valve
Filter
Fuel
storage
tank
A
Supply
Return
12
Oil Storage &
Supply System
Fire valve
Supply
Return
Fire valve sensor
Vent pipe
Fill pipe
Sludge
valve
Tiger Loop System (See Figures 3-3 and 3-4)
When The storage tank is below the
burner, an alternative to a two pipe
system can be achieved using a 'Tiger
Loop' type oil de-aerator. This effectively
removes the air from the oil supply on a
single pipe lift.
The de-aerator is connected close to
the boiler as a two pipe system (omitting
the non-return valve) as shown in Fig. 3-
3. Refer to the manufacturers
instructions supplied with the deaerator. The de-aerator must be
mounted vertically, as shown in Figures
3-3 and 3-4.
To prevent any possibility of fuel
fumes entering the building, the
de-aerator must be fitted outside in
accordance with BS 5410:1:1997.
!
WARNING
Tankmaster
Fuel
storage
tank
De-aeration device e.g
Tiger Loop see Figure 3-4
Pump (see section 3.2)
Figure 3-3: De-aeration device system
Figure 3-4: Tiger loop de-aeration device
To burner
From burner
From tank
Oil Storage &
Supply System
13
Figure 3-5: Burner pump connections
3.2 Burner Oil Connection
The fuel pump is supplied for use with a
single pipe fuel supply system. For use
on a two pipe system, it is necessary to
fit the By-pass screw into the tapping in
the return port. See Figure 3-5.
The By-pass screw is supplied in the
boiler accessory pack.
The procedure is as follows:
1. Remove the plastic burner cover
(two screws).
2. Remove and discard the blanking
plug from the return connection of
the pump and fit the By-pass screw
using a hexagonal key.
3. Connect the return oil flexible fuel
line to the pump.
4. Connect the
3
/8" to 1/4" BSP
adaptor to the flexible fuel line.
Flexible fuel lines and adaptors are
available to purchase from Grant
Engineering (UK) Ltd.
The burner cover may be left off until the
boiler is commissioned.
Oil inlet
connection
Return connection
By-pass screw
Pressure gauge connection
Pressure adjuster
Vacuum gauge connection
Solenoid
Supply to
nozzle
The blanking plug supplied in the
inlet (suction) port may now be
plastic and will not provide an oil
tight seal when the pump is running.
Ensure the supply from the tank is
connected to this port and the plastic
plug is discarded.
!
WARNING
14
Oil Storage &
Supply System
4 Boiler Installation Information
4.1 Introduction
The boiler is supplied already fully
assembled in a carton which is carefully
packed with packing materials. The
installation procedure therefore begins
with unpacking and uninstalling of the
packed boiler.
4.2 Boiler Location
The boiler must stand on a surface that
is firm and level. It does not require a
special hearth as the temperature of the
boiler base is less than 50°C.
Sufficient clearance must be allowed at
the front of the boiler to remove the
burner and baffles for servicing.
The Vortex Pro Combi 21e and 26e
boilers can be serviced from the front,
but it is preferable for any worktop
above the boiler to be removable.
The Vortex Pro Combi 36e requires a
removable section of worktop above the
boiler to provide access to components
on top of the boiler and for servicing.
Care should be taken when siting the
condensate trap if it is to be fitted
outside the boiler. Refer to Section 6.
4.3 Preparation for Installation
Carefully remove the packaging from the
boiler and remove it from the transit
pallet.
Pull off the boiler front panel and remove
the literature pack.
Lift off the two parts of the case top and
remove the water connecting fittings.
4.4 Installing the Boiler
You are now ready to install the boiler.
The main procedures are as follows:
• Make the water connections - see
section 5.2.
• Fit flue terminal - see section 9.
• Check the expansion vessel - see
section 4.5 below.
• Connect the power supply.
• Connect the fuel supply - see
section 3.
• Fill and vent the system - see
section 4.5.
4.5 Expansion Vessel
The expansion vessel fitted is supplied
with a charge pressure of 1.0 bar
(equivalent to a max. static head of 10.2
metres). The charge pressure must not
be less than the actual static head at
the point of connection. Do not
pressurise the vessel above 1.5 bar.
The central heating system volume,
using the expansion vessel as
supplied, must not exceed the
recommended volumes. Refer to
Section 2.1. If the system volume is
greater, an extra expansion vessel
(complying with BS4841) must be
fitted as close as possible to the
central heating return connection on
the boiler. The charge pressure of the
extra vessel must be the same as the
vessel fitted in the boiler.
Refer to BS7074:1:1989 for further
guidance.
The air charge pressure may be
checked using a tyre pressure gauge on
the expansion vessel Schraeder valve.
The vessel may be re-pressurised using
a suitable pump. When checking the air
pressure the water in the heating
system must be cold and the system
pressure reduced to zero.
4.6 Filling and venting the
system
The expansion vessel fitted is supplied
with a charge pressure of 1.0 bar
(equivalent to a max. static head of 10.2
metres). The charge pressure must not
be less than the actual static head at
the point of connection. Do not
pressurise the vessel above 1.5 bar.
Automatic and Manual Air Vents
The boiler is fitted with two Automatic
air vents at the top of the boiler, located
as follows:
• One on the top of the primary store.
• One on the heating flow pipe.
Refer to Figure 5-1.
Check that the small black plug on the
side of each air vent is screwed in fully.
Then unscrew it one complete turn - the
cap remains in this position thereafter.
A single manual air vent is also fitted at
the top of the boiler - on the return pipe.
Unscrew the cap one turn vent air from
the pipe during filling and then fully close
the cap.
Filling loop
If the flexible filling loop is used to fill the
system, ensure it is connected and that
the valve connecting it to the boiler is
open and the valve at the front is
closed.
A valve is open when the operating lever
is in line with the valve, and closed
when it is at right angles to it.
Ensure that the mains cold water supply
valve is open (operating lever in line with
the valve), then turn on the mains cold
water supply and gradually open the
front valve on the filling loop until water
is heard to flow.
Vent each radiator in turn, starting with
the lowest one in the system, to remove
air.
It is important the circulating pumps are
properly vented to avoid them running
dry and the bearings being damaged.
To gain access to the heating pump in
the Vortex Pro Combi e, it is necessary
to lower the control panel.
Loosen (but do not remove) the four
fixing screws securing the control panel
to the side panels, hinge the panel
forward to gain access to the pump.
Unscrew and remove the plug from the
centre of the pump. Using a suitable
screwdriver rotate the exposed spindle
about one turn. When water starts to
trickle out, replace the plug.
The Hot water pump must also be
vented as described above.
Check the operation of the safety valve
by turning the head anticlockwise until it
clicks. The click is the safety valve head
lifting off its seat allowing water to
escape from the system. Check that
this is actually happening.
Continue to fill the system until the
pressure gauge indicates between 0.5
and 1.0 bar. Close the fill point valve
and check the system for water
soundness, rectifying where necessary.
Water may be released from the system
by manually operating the safety valve
until the system design pressure is
obtained.
The air pressure in the vessel must
be checked annually.
!
NOTE
Boiler Installation
Information
15
The system design pressure (cold)
should be between 0.5 bar and 1.0 bar.
The pressure is equivalent to the
maximum static head in bar + 0.3 (1 bar
= 10.2 metres of water), where the
static head is the vertical height from the
centre of the expansion vessel to the
highest point of the system.
Close the valves either side of the filling
loop and disconnect the loop.
4.7 Regulatory Compliance
Requirements
Installation of a Grant VORTEX Pro
Combi e boiler must be in accordance
with the following recommendations:-
• Building Regulations for England
and Wales, and the Building
Standards for Scotland issued by
the Department of the Environment
and any local Byelaws which you
must check with the local authority
for the area.
• Model and local Water Undertaking
Byelaws.
• Applicable Control of Pollution
Regulations.
• The following OFTEC requirements:
• OFS T100 Polythene oil storage
tanks for distillate fuels.
• OFS T200 Fuel oil storage tanks
and tank bunds for use with
distillate fuels, lubrication oils and
waste oils.
Further information may be obtained
from the OFTEC Technical Book 3
(Installation requirements for oil storage
tanks) and OFTEC Technical Book 4
(Installation requirements for oil fired
boilers).
The installation should also be in
accordance with the latest edition of the
following British Standard Codes of
Practice:
• BS 715 Metal flue pipes, fittings,
terminals and accessories.
• BS 799:5 Oil storage tanks.
• BS 4543:3 Factory made insulated
chimneys for oil fired appliances.
• BS 4876 Performance requirements
for oil burning appliances.
• BS 5410:1 Code of Practice for oil
firing appliances.
• BS 5449 Forced circulation hot
water systems.
4.8 Completion
Please ensure that the OFTEC CD/10
installation completion report (provided
with the boiler) is completed in full.
Leave the top copy with the User.
Retain the carbon copy.
Ensure that the User Information pack
(supplied with the boiler) is handed over
to the Householder.
4.9 Before you Commission
To avoid the danger of dirt and foreign
matter entering the boiler the complete
heating system should be thoroughly
flushed out - before the boiler is
connected and then again after the
system has been heated and is still hot.
This is especially important where the
boiler is used on an old system.
For optimum performance after
installation, this boiler and its associated
central heating system must be flushed
in accordance with the guidelines given
in BS 7593:1992 'Treatment of water in
domestic hot water central heating
systems'.
This must involve the use of a
proprietary cleaner, such as Betz
Dearborn's Sentinel X300 or X400, or
Fernox Restorer. Full instructions are
supplied with the products, but for more
details of Betz Dearborn’s products,
view the website www.sentinelsolutions.net and for more details of
Fernox products view the website
www.fernox.com.
For Long term protection against
corrosion and scale, after flushing, it is
recommended that an inhibitor such as
Betz Dearborn's Sentinel X100 or
Fernox MB-1 is dosed in accordance
with the guidelines given in BS
7593:1992.
Failure to implement the guidelines will
invalidate the warranty.
4.10 Underfloor Heating
Systems
In underfloor systems it is essential that
the return temperature must be maintained
above 40°C to prevent internal
corrosion of the boiler water jacket.
4.11 Pipework Materials
In Grant boilers are compatible with
both copper and plastic pipe. Where
plastic pipe is used it must be of the
oxygen barrier type and be of the
correct class (to BS 7291:Part 1:2001)
for the application concerned.
4.12 Sealed Systems
If plastic pipe is used, the installer must
check with the plastic pipe
manufacturer that the pipe to be used
is suitable for the temperature and
pressures concerned.
Plastic pipe must be Class S to
BS 7291: Part 1:2001.
4.13 Underfloor Pipework
Plastic pipe may be used on Underfloor
systems where the plastic pipe is fitted
after the thermostatic mixing valve.
Copper tube must be used for at least
the first metre of flow and return primary
pipework between the boiler and the
underfloor mixing/blending valves.
• BS 7593 Code of Practice for
treatment of water in heating
systems.
• BS 7671 Requirements for electrical
installations, IEE Wiring Regulations.
Failure to install and commission
appliances correctly may invalidate
the boiler warranty.
!
NOTE
Before starting any work on the
boiler, or fuel supply please read the
health and safety information given in
Section 14.
!
WARNING
The first metre of pipework
connected to both the heating flow
and return connections of the boiler
must be made in copper on all types
of system - sealed or open-vented.
!
NOTE
The boiler incorporates a lowpressure switch to shut off power to
the boiler if the system pressure
drops below 0.2 bar.
!
WARNING
5 Pipe Connections
16
Pipe Connections
5.1 Water Connections
Water connections may be from the
rear, left or right hand side. If using low
level side exit flue, connections must be
on the opposite side to the flue.
Flow and return connections - All
models are supplied with a push-fit
elbow connection for the heating flow
and return - 22 mm (Vortex Pro Combi
21e and 26e) or 28 mm (Vortex Pro
Combi 36e).
Hot water connections - All models are
supplied with push-fit elbow
connections for the cold water mains
inlet pipe and hot water outlet pipe.
These are 15mm for the Vortex Pro
Combi 21e and 26e, and 22mm for the
Vortex Pro Combi 36e.
5.2 Making the Water
Connections
Flow and return pipework can be routed
to either side of the boiler, dependant on
the flue system used, from the push-fit
elbows (supplied) on the flow and return
connection. Refer to Figure 5-1.
Holes are provided in the rear of the
casing side panels to allow the
condensate pipe to be run through the
back of the boiler. It will be necessary to
remove the back panel from the boiler
casing to fit this pipework, and to refit
the panel before placing the boiler in its
final position. See Figure 6-3.
If access will be restricted, make any
connections to the boiler before placing
it in its final position.
If using a balanced flue system - Install
the balanced flue system before
connecting the heating system
pipework to the boiler.
All Models
A 15 mm discharge pipe must be
connected to the safety valve outlet
connection. The pipework between the
safety valve and the boiler must be
unrestricted, that is, no valves. The
discharge pipe should be run to the
outside of the building and terminate so
that it cannot cause injury to persons or
property.
A drain tap is provided at the bottom on
the front of the boiler (and also on the
hot water store on the Vortex Pro
Combi e).
All pipes to be fitted into the push-fit
connectors provided should be cut
using a pipe slicer or pipe cutter - to
leave the pipe ends with a slight
radius and free from any burrs or
sharp edges.
Pipes to be used with these fittings
should not be cut square using a
hacksaw.
!
CAUTION
Figure 5-1: Vortex Pro Combi e pipe positions
Heating flow
connection
Heating circulating
pump
Heating
return
Flow switch
Cold water inlet
isolating valve
Cold water inlet
Automatic air vent
Safety valve
Pressure
switch
Manual
air vent
Primary return
isolating valve
Non return
valve
Automatic
air vents
Boiler flow
sensor and
overheat
thermostat
bulb
Safety valve
outlet
Condensate
Disposal
17
5.3 Domestic Hot Water
System
To maintain a longer and more
consistent hot water temperature, a flow
restrictor is factory fitted to all models
except the Vortex Pro Combi 36e, to
limit the flow rate to approximately 15
litres/minute.
The flow restrictor is located in the
outlet side of the cold water inlet
isolating valve.
The incoming mains water pressure
should be between 1 and 8 bar to
ensure efficient operation.
If the pressure is above 8 bar a pressure
reducing valve must be fitted.
The boiler may still operate down to a
pressure of 1.0 bar but with a reduced
flow rate. The minimum flow rate
needed for the flow switch to operate is
3 litres/minute.
To ensure economic use, the pipe runs
between the boiler and hot taps should
be as short as possible and in 15 mm
copper pipe or 22 mm for the Vortex
Pro Combi 36e only. Where possible the
pipework should be insulated to reduce
heat loss.
All taps and mixing valves used in the
domestic hot water system must be
suitable for operating at a mains
pressure of up to 8 bar.
If required, a shower may be fitted in the
domestic hot water system. It is
recommended that thermostatically
controlled shower valves are used to
protect against a flow of water at too
high a temperature. If a fixed head type
shower is used, no anti-syphonage
devices are required. If a loose or
flexible head type shower is used, it
must be arranged so that the head
cannot fall closer than 25 mm above the
top of the bath, thereby preventing
immersion in the bath water. If this is not
practicable, an anti-syphonage device
must be fitted at the point of the flexible
hose connection.
The supply of hot and cold mains water
direct to a bidet is allowed (subject to
local Water Undertaking requirements)
provided that the bidet is of the over-rim
flushing type. The outlets should be
shrouded and unable to have a
temporary hand held spray attached.
Arrangements for antisyphonage are not
necessary.
5.4 To use the Water Hardness
Kit
Fill a clean container with a sample of
water from the mains cold water supply
to the boiler.
Immerse the test strip in the water for
approximately one second, ensuring
that all the test zones are fully wetted.
Shake off the surplus water and wait for
one minute.
Assess the colouration of the test zones
using the following chart.
If the hardness reading is found to be in
the medium to very hard range (the
shaded area), it is essential that some
form of water conditioner or softener is
fitted to reduce scale formation within
the combination boiler. Failure to do so
may invalidate both the manufacturers
warranty and any extended warranty
covering the appliance.
The water conditioner or softener
should be fitted to the cold water supply
serving the appliance and in accordance
with the manufacturer’s instructions.
Grant Engineering (UK) Ltd. cannot be
held responsible for any damage or
misuse caused by the fitting of any
water conditioning device.
Before the mains water supply pipe is
connected to the boiler, it should be
thoroughly flushed out to avoid the
danger of dirt or foreign matter entering
the boiler.
The mains water connection to the
boiler must be the first connection from
the mains supply.
Please protect the domestic hot
water system from harmful effects
of scale. Problems caused by the
build-up of limescale are not covered
under the terms of the warranty.
!
CAUTION
A water hardness test kit is supplied
with the boiler. Should the total
hardness of the water supply exceed
125 ppm, an in-line scale inhibitor
should be fitted in the cold water
supply to the boiler.
Consult the local Water Undertaking
if in doubt.
Do not immerse the test strip in
running water and avoid contact.
!
NOTE
Green Areas Violet Areas Hardness Total Hardness mg/l (ppm)
4 0 Very Soft <50 mg/l calcium Carbonate
3 1 Soft <70 mg/l calcium Carbonate
2 2 Medium <125 mg/l calcium Carbonate
1 3 Hard <250 mg/l calcium Carbonate
0 4 Very Hard <370 mg/l calcium Carbonate
Note: (1mg/l = 1 ppm (part per million)
6 Condensate Disposal
18
Condensate
Disposal
6.1 General Requirements
When in condensing mode the Grant
Vortex PRO Combi e boilers produce
condensate from the water vapour in the
flue gases. This condensate is slightly
acidic with a ph value of around 3
(similar to vinegar). Provision must be
made for the safe and effective disposal
of this condensate.
Condensate can be disposed of using
one of the following methods of
connection:
Internal Connection (preferred option):
• Into an internal domestic waste
system (from kitchen sink, washing
machine, etc.).
• Directly into the soil stack.
External Connection:
• Into an external soil stack.
• Into an external drain or gulley.
• Into a rainwater hopper (that is part
of a combined system where sewer
caries both rainwater and foul water).
• Purpose made soakaway.
All condensate disposal pipes must
be fitted with a trap - whether they are
connected internally or externally to a
domestic waste system/soil stack or run
externally to a gully, hopper or soakaway.
6.2 Connections
Connections into a rainwater hopper,
external drain or gulley should be
terminated inside the hopper/
drain/gulley below the grid level but
above the water level.
Condensate disposal pipes should not
be connected directly into rainwater
downpipes or to waste/soil systems
connected to septic tanks.
Condensate should not be discharged
into ’grey water’ systems that re-use
water used in the home (not including
water from toilets).
It should be noted that connection of a
condensate pipe to the drain may be
subject to local Building Control
requirements.
6.3 Pipework
Condensate disposal pipework must be
plastic (plastic waste or overflow pipe is
suitable).
Condensate disposal pipes should
have a minimum ‘nominal’ diameter of
22mm (
3
/4”) - e.g. use 21.5mm OD
polypropylene overflow pipe.
Condensate disposal pipes must be
fitted with a fall (away from the boiler) of
at least 2.5° (~45mm fall per metre run).
Copper or steel pipe is NOT suitable
and MUST NOT be used.
For a boiler installed in an unheated
area such as an outhouse or garage,
all condensate pipework should be
considered as an ‘external’.
6.5. Condensate Soakaway
To keep external pipework to a
minimum, locate the soakaway as close
as possible to the boiler but ensure it is
at least 500mm from building
foundations and away from other
services, e.g. gas, electricity, etc.
The condensate pipe may be run above
or below ground level and can enter
either the top or side of the soakaway
tube. Refer to Figure 6-1.
Ensure that the drainage holes in the
soakaway tube face away from the
building.
Backfill both the soakaway tube and the
hole around it, with 10mm limestone
chippings.
Only use a soakaway where the soil is
porous and drains easily. Do not use in
clay soils or where the soil is poorly
drained.
Any damage due to condensate
backing up into the boiler due to a
high water table, in the case of a
soakaway, or flooded drains when
the condensate disposal is via a
gulley or soil stack, is not covered by
the Grant product warranty.
Where it is not possible for the pipe
to fall towards the point of discharge
- either internally into a waste system
or externally to a gulley (e.g. for
boilers installed in a basement), it will
be necessary to use a condensate
pump.
Condensate disposal pipes should be
kept as short as possible and the
number of bends kept to a minimum.
Pipes should be adequately fixed to
prevent sagging, i.e. at no more than
0.5 metre intervals.
6.4 External Pipework
Ideally, external pipework, or pipework
in unheated areas, should be avoided. If
unavoidable, external pipework should
be kept as short as possible (less than 3
metres) and 32mm waste pipe used to
minimise the risk of ice blocking the
pipe in freezing conditions.
The number of bends, fittings and joints
on external pipes should be kept to a
minimum to reduce the risk of trapping
condensate.
!
NOTE
!
NOTE
!
NOTE
!
CAUTION
Figure 6-1: Purpose made condensate soakaway
32mm waste pipe
external to the building
Two rows of 3 x 12mm
holes at 25mm centres and
50mm from the bottom of
the tube. Holes facing away
from the property.
Backfill with
10mm limestone
chippings
Sealed
end
100mm
plastic tube
Cement seal
Ground level
2.5° fall
25mm
300mm
400mm min.
Condensate
Disposal
19
6.6 Condensate Trap
Grant Vortex PRO boilers are supplied
with a factory-fitted condensate trap to
provide the required 75mm water seal in
the condensate discharge pipe from the
boiler.
This trap incorporates a float (which will
create a seal when the trap is empty)
and an overflow warning outlet (fitted
with a plastic sealing cap).
See Figure 6-2.
6.9 External Condensate Trap
Fitting
To re-locate the factory-fitted trap
outside the boiler casing, use the
following procedure:
6.8 Inspection and Cleaning of
Trap
The trap must be checked at regular
intervals (e.g. on every annual service)
and cleaned as necessary to ensure
that it is clear and able to operate.
To inspect and clean the trap, perform
the following procedure:
1. Disconnect flexible condensate
hose from inlet connector.
2. Unscrew the inlet connection nut.
3. Remove the ‘top hat’ inlet
connector and nut from trap.
4. Disconnect the condensate disposal
pipe from the trap outlet.
5. Remove trap from bracket.
6. Remove float from trap - clean if
necessary.
7. Inspect inside of trap and clean as
necessary.
8. Re-assemble trap, re-fit to boiler
and re-connect flexible hose. Ensure
that hose is fully pushed onto the
‘top hat’ inlet connector.
With the trap fitted inside the boiler
casing, the sealing cap must be
fitted. If the trap is re-located outside
the boiler then the following applies:
• If connecting the condensate discharge
- either internally or externally - into a
waste system or soil stack - the sealing
cap must be fitted in the trap outlet.
• On external discharge systems to a
hopper, gully or soakaway, the
sealing cap should be removed from
the trap outlet.
• If there is any discharge of
condensate from the overflow
outlet, this could indicate a
blockage (possibly due to freezing).
Turn off the boiler and investigate
the cause. If necessary contact your
service engineer for assistance.
6.7 Condensate Disposal
Pipework
The condense trap outlet is at an angle
of 48° below the horizontal. This is to
automatically gives a 3° fall on any
‘horizontal’ runs of condense disposal
pipe. Refer to Figure 6-1 and see trap
outlet/pipe.
The outlet of the trap will accept
21.5mm OD to 23mm OD
Polypropylene overflow pipe for the
condensate discharge pipe.
This discharge pipe can exit through the
left side of the boiler through one of two
pre-cut ‘knock-outs’ in the lower part of
the left casing panel. Push out the
‘knock-out’ from the required hole
taking care not to distort the side panel.
Refer to Figure 2-1 for this on the Pro
Combi 21e or 26e, or Figure 2-2 for this
on the Pro Combi 36e.
The trap is factory-fitted inside the boiler
casing - mounted on the inside of the
left side panel - in an accessible position
to allow for routine maintenance.
A flexible hose connects the outlet of
the condensing heat exchanger to the
trap inlet. Ensure the straight connector
on the hose is fully pushed onto the ‘top
hat’ inlet connector of the trap.
Figure 6-2: Condensate trap
If required, this condensate trap may
be re-located outside the boiler
casing. Refer to procedure given in
‘external condensate trap’. This
procedure must be carried out
before the boiler is installed.
!
NOTE
The bottom bowl is sealed to the trap
body and cannot be removed.
!
NOTE
End cap is sealed to trap body. DO
NOT attempt to remove it for cleaning.
!
NOTE
Failure to regularly check and clean
the condensate trap may result in
damage to the boiler and will not be
covered by the Product Warranty.
!
NOTE
Condensate
drain pipe
from boiler
Unscrew
this cap for
maintenance
access
Overflow
warning
outlet
(with cap)
Condensate
trap
Condensate
outlet to
drain
End cap
Care should be taken when siting the
trap such that the overflow outlet is
readily visible and that any
condensate overflowing from the
outlet cannot cause either a hazard
to persons or damage to surrounding
property or equipment.
!
WARNING
20
Condensate
Disposal
6 Condensate Disposal
Figure 6-3: Gaining access to the
condensate outlet
This procedure must be carried out
before the boiler is installed.
!
NOTE
The top of the trap must be below
the condensate connection on the
boiler.
!
NOTE
The flexible hose must fall
continuously from the outlet to the
top of the trap.
!
NOTE
1. Remove both the top casing
panel(s) from the boiler.
2. Unscrew and remove the screws
fastening the left side panel to the
rear casing panel of the boiler.
3. Carefully separate the left side and
rear panels just enough to gain
access to the condensate outlet on
the left rear of the condensing heat
exchanger (see Figure 6-3).
4. Push out pre-cut ‘knock-out’ from
condensate outlet hole in rear of left
side casing panel.
5. Remove right angle end of flexible
condensate discharge hose from
outlet connection on condensing
heat exchanger.
6. From front of boiler, remove straight
connector end of flexible hose from
top of condensate trap.
7. Reverse flexible hose and pass the
straight connector end through the
new hole in the left hand casing
panel. Push the straight connector
firmly onto the condensate outlet
connection of the condensing heat
exchanger as far as possible.
8. Refit the left hand casing panel to
the rear panel using the reverse
procedure, ensuring all fixing screws
are used.
9. Remove the trap from the mounting
bracket.
10. Unscrew and remove the trap
mounting bracket from the left side
panel.
11. Fix the trap mounting bracket to the
wall adjacent to the boiler in the
required position.
12. Re-fit the trap to the mounting
bracket. The mounting bracket
supplied with the trap must be used
- the trap should not be supported
by the condensate pipework only.
13. Connect the flexible condensate
hose to the trap - pushing the right
angle hose connector onto the trap
inlet connection.
Rear
panel
Left hand
side panel
Sealed Systems
21
7 Sealed Systems
7.1 System Models
All Grant Vortex Pro Combi e boilers are
supplied for use as part of a sealed
system complying with the requirements
of BS 5449.
The maximum temperature of the
central heating water is 78° C.
• Pressure relief safety valve
complying with BS 6759 and set to
operate at 2.5 bar. The discharge
pipe must be routed clear of the
boiler to a drain, in such a manner
that it can be seen, but cannot
cause injury to persons or property.
• Automatic air vent, fitted to the top
of the boiler, ensures the boiler is
vented.
• Filling loop. This must be isolated
and disconnected after filling the
system.
Refer to Section 4.5 for further details of
the expansion vessel.
The expansion vessel charge pressure
should always be slightly greater than
the maximum static head of the system,
in bar, at the level of the vessel (1 bar =
10.2 metres of water). See Figure 7-1.
The boilers are supplied with the
following items factory fitted:
• A diaphragm expansion vessel
complying with BS 4814, precharged at 1.0 bar, size as follows:
10 litre for Vortex Pro Combi 21e
12 litre for Vortex Pro Combi 26e
14 litre for Vortex Pro Combi 36e.
System pressure gauge, with an
operating range of 1 to 4 bar.
The system fill pressure (cold) should be
0.2-0.3 bar greater than the vessel
charge pressure - giving typical system
fill pressures of approx 0.5 bar for a
bungalow and 1.0 bar for a two-storey
house. Refer to the Domestic Heating
Design Guide for more information if
required.
If thermostatic radiator valves are fitted
to all radiators, a system by-pass must
be fitted. The bypass must be an
automatic type.
Provision should be made to replace
water lost from the system. This may be
done manually (where allowed by the
local Water Undertaking) using the filling
loop arrangement supplied with the
boiler.
Filling of the system must be carried out
in a manner approved by the local
Water Undertaking.
Where allowed, the system may be filled
via the filling loop supplied (the loop
arrangement includes a double check
valve assembly).
All fittings used in the system must be
able to withstand pressures up to 3 bar.
Radiator valves must comply with the
requirements of BS 2767(10):1972.
One or more drain taps (to BS 2879)
must be used to allow the system to be
completely drained.
The expansion vessel is connected via a
flexible hose to allow it to be moved to
gain access to the baffle cleaning cover.
When replacing the vessel, care should
be taken to ensure that the flexible
connecting hose is not twisted.
Figure 7-1: Sealed system
Static head of system
Heating flow
Heating
return
By-pass if required
(automatic type)
350mm
Boiler
Expansion
vessel
If thermostatic radiator valves
are fitted, the system must
incorporate an adequate by-pass.
When designing a system, the pump
head, expansion vessel size, and
radiator mean temperature are
amongst the factors that must be
considered. See Section 4.5.
!
NOTE
Ensure that the expansion vessel is
of sufficient size for the system
volume (including the volume of the
boiler). If necessary a second vessel
may need to be fitted to the system.
Refer to Section 2.1 for system
volume. To determine total vessel
volume required refer to
BS7074:1:1989 or the Domestic
Heating Design Guide.
!
NOTE
Stop valve
Water mains
Domestic
hot water
Domestic
cold water
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