To supplement the detailed technical brochures, technical advice on the application and use of products in the
Hamworthy Heating range is available from our technical team in Poole and our accredited agents.
Site Assembly 01202 662555
Hamworthy offer a service of site assembly for many of our products in instances where plant room area is restricted.
Using our trained staff we offer a higher quality of build and assurance of a boiler built and tested by the manufacturer.
Commissioning 01202 662555
Commissioning of equipment by our own engineers, accredited agents or specialist sub – contractors will ensure the
equipment is operating safely and efficiently.
Maintenance Agreements 01202 662555
Regular routine servicing of equipment by Hamworthy service engineers inspects the safety and integrity of the plant,
reducing the risk of failure and improving performance and efficiency. Maintenance agreements enable our customers to
plan and budget more efficiently.
Hamworthy provide a rapid response breakdown, repair or replacement service through head office at Poole and accredited agents throughout the UK.
Spare Parts 01202 662525
A comprehensive spare parts service is operated from our factory in Poole, providing replacement parts for both current
and discontinued products. Delivery of parts and components is normally from stock within seven days. However, a next
day delivery service is available for breakdowns and emergencies.
Customer Services
Wimborne GM Boilers
Gas/Oil Fired Cast Iron Sectional Boilers
420kW to 1070kW
Installation, Commissioning
and Servicing Instructions
NATURAL GAS
CLASS D (35 sec fuel oil)
THE WIMBORNE BOILER IS INTENDED FOR USE AS A COMMERCIAL APPLIANCE.
THE GAS FIRED VARIANTS ARE FOR USE ON GROUP H NATURAL
ND
GAS (2
FAMILY) I2H . THE OIL FIRED VARIANTS ARE FOR USE ON
CLASS D (35 sec FUEL OIL). PLEASE ENSURE RELEVANT
INFORMATION REQUIRED WITHIN DOCUMENT IS FOUND
RELATING TO SPECIFIC FUEL TO BE FIRED BEFORE OPERATING
THE BOILER.
Figure A Typical schematic boiler installation layout 3
Figure B Performance and General Information 4
Figure C Boiler Dimensions 5
Figure D Water Connections 5
Figure E Mechanical ventilation flow-rates 10
Figure F Cold feed and vent pipe sizes 11
Figure G Control panel wiring details (High/ Low Burner Control) 14
Figure H Composition of sections within heat exchanger 15
Figure I Composition of heat exchanger assembly—exploded view 15
Figure J Applying the sealant 16
Figure K Composition of Boiler casing assembly 23
Figure L Exploded view of boiler 28
Figure M Matched burner/ boiler combinations gas 33
Figure N Matched burner/ boiler combinations oil 34
Figure O.1 Riello Oil nozzle selection 35
Figure O.2 Nu-Way Oil nozzle selection 35
Figure P Combustion target Figures 36
Figure Q Combustion chamber and burner data 36
The Wimborne GM boiler range consists of 10 gas or
oil fired cast iron sectional boilers with outputs
ranging from 420kW to 1130kW. Refer to Section
2.0 for details on Natural Gas and Oil firing.
Wimborne GM boilers can be used individually, or in
a multi-boiler configuration, and are suitable for use
on either open-vented or sealed low temperature hot
water heating systems. For hot water production they
can be used in conjunction with calorifiers or indirect
hot water cylinders.
Portland pressurisation units are available from
Hamworthy Heating Ltd for sealed systems.
1.2 Packing Lists
Accessory Pack
Burner Model - Accessory Pack Quantities
Description
Guide
Ring
`O` Ring
7.3mm
Boiler
Cement
Pack
Silicon
Sealant
Tube
Primer Silicon
Tie Bolt
M12 x 230
Self-Tapping
Screw
6 7 8 9 10 11 12 13 14 15
10 12 14 16 18 20 22 24 26 28
10 12 14 16 18 20 22 24 26 28
5 5 6 7 8 9 10 10 11 11
9 11 12 13 15 16 18 19 20 21
2 2 2 3 3 3 3 3 4 4
20 24 28 32 36 40 44 48 52 56
70 110 110 110 130 130 130 150 150 150
GM
Description
Intermediate
section
Front
section
Rear
section
Rear flue cover
250mm dia.
Rear flue cover
350mm dia.
Hinged
front door
Casing
pack
Insulation
Pieces
Flue tube insert
pack (22 off)
Control Panel
Assembly.
Installers Guide
500001113
Accessory
pack
Burner Model - Packing List Quantities
GM
6 7 8 9 10 11 12 13 14 15
4 5 6 7 8 9 10 11 12 13
1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1
1 1 1 1 - - - - - -
- - - - 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1
1.3 Sectional Boilers
Wimborne GM sectional boilers are supplied ready
for on-site assembly.
The heat exchanger consists of:
a. A front section
b. Plain intermediate sections.
c. A rear section
These sections are connected to each other using
nipples and ‘O’ rings and are held together by short
lacing bolts.
The section to section flue gas seal is made by a
mastic strip located in a groove around the inner and
outer perimeter of each section.
The boilers are of the reverse flame design with the
first two passes in the combustion chamber. The final
pass uses turbulator tubes to increase the heat
exchange area and thus enhance thermal efficiency
in use.
Wimborne GM boilers have an operating efficiency of
over 82% based on gross CV.
The heat exchanger assembly is completed by cast
iron front and rear combustion chamber plates and
access plates for the cleaning and inspection of the
heat exchanger flue ways (rear only), all of which are
internally lined with a fibre insulation board. The
burner mounts onto the front plate which is hinged,
suitable for left or right hand operation.
The flow and return water connections are located on
top and to the rear of the boiler. Refer to Figure D for
details.
The Wimborne GM boiler is available with high/low
burners for operation on Class D (35 second) fuel
oil, Natural Gas I
(Second Family).
2H
The boiler is supplied with a pre-wired control panel
which contains:
a. A fuse
b. An illuminated mains on/off switch
c. Boiler control thermostats (On/Off) & (High/Low)
d. Boiler run, (High/Low) and lockout lamps.
e. A temperature limiter (overheat thermostat) to shut
down the boiler should the water temperature in the
heat exchanger exceed 110
°
C - with manual reset.
f. An overheat lamp
g. A water temperature thermometer (temp. gauge)
h. Flying leads and plugs to connect to the burner
i. Volt free relay contacts for normal run, overheat
and lockout.
The boiler is housed in a powder coated sheet steel
casing which is supplied flat-packed for on-site
assembly. Refer to Section 10.3 for casing assembly
procedure.
1.4 Hydraulic Testing
All Wimborne GM boiler sections are hydraulically
tested, ensuring the Wimborne GM boiler is suitable
for use on systems with maximum working pressures
of up to 6 bar.
1.5 Boiler Set
The boiler is normally supplied as a set of equipment
comprising the following:
a. Cast iron sections mounted on pallets
b. Accessory kit and tie rods
c. Casing panels
d. Insulation blankets
e. Flue tubes - 22 off
f. Control panel
g. Matched burner: fuel oil or gas
h. Burner mounting plate, drilled ready to accept
burner
i. Oil burner nozzle/s where applicable.
1.6 COSHH Information
Irritant
The boiler insulation blankets are noncarcinogenic, mineral wool fibre, and may
cause inflammation and irritation on
immediate or repeated or prolonged
contact with the skin or if inhaled. The use of suitable
protective clothing is highly recommended. Avoid
contact with skin and direct inhalation
1.6.1 In case of contact with the eyes, rinse
immediately with plenty of water and seek medical
advice.
1.6.2 In case of contact with skin, wash immediately
with plenty of water.
1.6.3 In case of inhalation, retire to clean air supply
and seek medical advice.
MINIMUM FLOW RATE @ 20°C l/m 301 344 394 452 516 573 631 681 731 767
MAXIMUM WATER PRESSURE bar g. 6
MAXIMUM FLOW TEMPERATURE °C 90
MINIMUMRETURN TEMPERATURE °C 50
WATER CONTENT l 285 330 375 420 465 510 555 600 645 690
WEIGHT (FULL) WITHOUT BURNER kg. 1745 1985 2225 2455 2695 2935 3175 3470 3710 3955
DIMENSION - L (boiler overall length) mm 1255 1435 1615 1795 1975 2155 2335 2515 2695 2875
DIMENSION - B (base overall length) mm 970 1150 1330 1510 1690 1870 2050 2230 2410 2590
Note:- For matched burner/boiler combinations refer to Figure M.
For combustion target figures, refer to Figure O.
# if boilers are to be installed adjacent to each other, the minimum spacing can
be reduced to 200mm, provided that the doors hinge in opposite directions.
Gas Safety (Installation and Use) Regulations
1994 – (As amended). It is the law that all gas
appliances are installed by competent persons, in
accordance with the above regulations. Failure to
install appliances correctly could lead to prosecution.
It is in your own interest, and that of safety, to ensure
that this law is complied with.
The installation of the boiler MUST be in accordance with
the relevant requirements of the Gas Safety Regulations,
Building Regulations, Fire Regulations, I.E.E. Regulations
and the bylaws of the local water undertaking.
The installation should also be in accordance with any
relevant requirements of the local gas region and local
authority and the relevant recommendations of the
following documents :-
British Standards
BS 5410 Code of practice for oil firing.
Part 2 Installations of 44 kW and above
capacity for space heating, hot water
and steam supply purposes.
BS 5854Code of practise for flues and flue structures in buildings.
See paragraph 5 (3.6).
BS 6644Specification for installation of gas fired hot water boilers of rated inputs between
60kW & 2MW.
BS 6700Design, Installation, testing and
maintenance of services supplying water
for domestic use.
BS 6880Code of practice for low temperature hot water heating systems of output greater
than 45kW.
Part 1 Fundamentals & design considerations.
Part 2 Selection of equipment.
Part 3 Installation, commissioning and
maintenance.
BS 7074Application, selection and installation of expansion vessels and ancillary equipment
for sealed water systems.
Part 2Code of practice for low and medium temperature hot water systems.
BS CP342 Code of practice for centralised hot
water supply.
Part 2 Buildings other than individual dwellings.
I. Gas. E. Publications
IGE/UP/1 Soundness testing and purging of
industrial and commercial gas I
installations.
IGE/UP/1A Soundness testing and direct purging
of small low pressure industrial and
commercial natural gas installations.
IGE/UP/2 Gas installation pipework, boosters
and compressors in industrial and
commercial premises.
IGE/UP/10 Installation of gas appliances in
industrial and commercial premises
Pt 1 flued appliances.
Health and Safety Executive
Guidance note PM5 Automatically controlled steam
and hot water boilers.
CIBSE Publications
"CIBSE Guide"
It is impractical in this document to specify all relevant
information, but the following extracts from the above
references are emphasised since failure to comply with
these requirements will almost certainly result in an
unsatisfactory installation.
3.2 Feed Water Quality
If the boiler feed water has a high degree of
hardness, it is recommended that the water be
treated to prevent precipitation of scale or sludge in
the boiler water passageways. Details of additives
can be obtained from any reliable manufacturer of
water treatment products or the local water authority.
It should be noted however, that even if the boiler water is
of average hardness, not requiring treatment, subsequent
draining of the system for repair or constant make-up
water due to an undetected leak will cause additional
deposits and gradual build-up of scale. It is essential
therefore, that leaks are attended to promptly and
draining is kept to an absolute minimum.
It is recommended that the system be flushed out at least
twice before any water treatment is added. If any doubt
exists regarding the internal cleanliness of an old system,
consideration should be given to the fitting of a coarse
filter in the return pipework to the boiler/s.
Care should be taken in the initial design and layout
having due regard for adequate water flow through the
boilers and the influence of the system controls.
It is recommended that the system design should ensure
a minimum return temperature of 50 °C.
If the temperature/flow-rates of the application
cannot meet those given in Figure B, it may be
necessary to incorporate mixing valves and shunt
pumps to ensure that the boiler will operate
satisfactorily. Figure B shows recommended and
minimum water flows required with the associated
pressure losses. The control system and valves,
where fitted, should be regulated to avoid lower flows
occurring.
3.4 Time Clock Control
In order to avoid local overheating and progressive
calcium deposition at zero flow conditions where
boilers are operated from time clocks, provision
should be made for a 5 minute circulating pump
over-run after the last boiler has ceased firing.
NOTE:- Time clocks should not interrupt live, neutral or
earth connections, see Section 9.0: Electrical Supply for
details.
See Figure G for wiring details.
3.5 Minimum System Water Pressure
To comply with guidance note PM5 (Health and Safety
Executive), the minimum pressure requirements at the
boiler are given below as examples :-
1) Single installed boiler running at 82°C flow
temperature. Minimum head required is not less than 2
metres or 0.2 bar.
2) Single installed boiler running at 95°C flow
temperature. Minimum head required = 5.1 metres or
0.5 bar. See Section 8.10.1 for details.
3) Modular boiler installation running at 82°C flow
temperature and 11°C rise across system. Minimum
head required = 4.3 metres or 0.42 bar.
4) Modular boiler installation running at 82°C flow
temperature and 15°C rise across system. Minimum
head required = 9.4 metres or 0.92 bar. See Section
8.11 for Pressurised Water Systems.
4.0 LOCATION
The boiler location must permit the provision of a
satisfactory flue system, and provide adequate space
around the boiler for servicing and air circulation.
Sufficient space must be provided at the front of the
boiler to allow the removal of the burner assembly for
servicing/replacement, and at the rear for installation
of pipes, valves and flue.
Sufficient clearance around the boiler must also be
provided to allow access for servicing. Refer to
Figures C & D for recommended clearances.
The boiler room, or compartment, housing the boiler/
s - whether specifically constructed for the purpose,
or a modification of an existing space - should be in
accordance with the requirements of either BS 6644,
or BS 5410 Part 2, as appropriate.
The compartment housing the boiler must have
permanent air vents communicating directly with the
outside air at both high and low level. Refer to
Section 7.0 for details.
Where a separate purpose built boiler room is not
available, measures should be taken to protect the
boiler or boilers from damage, and the boiler should
be sited such that extraneous material cannot be
stored next to, or against it.
The boiler must be installed on a suitable level noncombustible surface, capable of withstanding
temperatures of 65
°
C and able to support the weight
of the boiler (including pipework and ancillary
equipment) when filled with water. A steel sheet can
be placed beneath the boiler cradle to facilitate
movement of the boiler during assembly. The plinth
must be level, non-combustible, 80mm nominal
height, and must be equal in width to the boiler
casing dimensions.
IMPORTANT:- the plinth must not protrude from the
rear of the boiler to enable fitting of the extension
turrets on the rear return connections.
The local gas region should be consulted at the
installation planning stage to either determine the
feasibility of providing a gas supply or, where there is
an existing supply, to ensure that the meter capacity
is adequate for the rated input of the proposed new
boiler. An existing gas service pipe must not be
used without prior consultation with the local gas
region.
5.2 Gas Meters
A new gas meter will be connected to the service pipe by
the local gas region, or a local gas region contractor. An
existing meter should be checked, preferably by the gas
region, to ensure that it is adequate to deal with the rate
of gas supply required.
5.3 Gas Supply Pipes
Supply pipes must be fitted in accordance with IM/16.
Pipework from the meter to the boiler must be of
adequate size. Do not use pipes of a smaller size than
the boiler gas connection. The complete installation
must be purged and tested for soundness as described
in IM/2 and IM/5 as appropriate.
A manual shut off valve must be fitted on the incoming
gas supply pipe, adjacent to each boiler, in an easily
accessible position.
5.4 Boosted Gas Supplies
Where it is necessary to employ a gas pressure booster,
the controls must include a low pressure cut-off switch at
the booster inlet. The local gas region must be consulted
before a gas pressure booster is fitted.
5.5 Boiler House Gas Control Valve
A manual valve for boiler house isolation shall be fitted in
the gas supply line. It shall be clearly identified and
readily accessible for operation, preferably by an exit.
5.6 Oil Supply
The oil storage & supply system should be designed
and installed in accordance with BS5410:Pt.2, as
appropriate.
The following notes are given as guidance :-
5.6.1 Oil Storage Tank
The oil storage tank should be of sufficient capacity
to permit economic deliveries of oil to be taken.
Reference should be made to oil distributor for
advice.
The tank should be installed such that:
a. The oil outlet should be higher than the top of the
oil burner pump. If site conditions prevent this, then
a suction lift (or 'two-pipe') fuel supply system must
be used.
b. The maximum head on the suction side of the oil
pump should not exceed 4 metres (14 feet).
c. The base should be sloped away from the outlet
and towards a drain cock to allow draining of any
water or sediment from the tank.
d. It is sited outside, if possible, and complies fully
with the requirements of the relevant British
Standards and Local Authority Regulations.
5.6.2 Oil Supply Lines
The oil supply line/s between storage tank and
burner should be run in copper, steel or aluminium
pipe. Galvanised pipes and fittings should not be
used. All pipework and fittings must be oil-tight, with
any screwed joints made good with an oil resistant
compound. The supply line should terminate
adjacent to the burner with an isolating valve and
metal bowl filter (with replaceable filter element). All
burners are supplied with flexible oil pipes to make
the final connection between the oil supply pipe and
the burner
5.6.3 Gravity Feed Supply
Where the delivery connection of the storage tank is
above the level of the pump inlet on the burner a
'single pipe' gravity feed system can be used. At no
point in this system should the supply pipework be
higher than the lowest level of fuel in the tank.
5.6.4 Suction Lift Supply
Where the delivery connection of the tank is below
the level of the pump inlet on the burner a 'two-pipe'
fuel supply system MUST be used. This system
uses the burner pump to provide a circulation of oil to
and from the tank.
NOTE:- Burner pumps can be supplied ready for use
on a 'single-pipe' system. For use on a 'two-pipe'
system it may be necessary to fit the pump with a
by-pass plug. Refer to technical information supplied
with burner.
The return line should terminate within the oil tank at
the same level as the suction line, in which case a
non-return valve is not required. If the return line
terminates above the fuel level, a non-return valve
MUST be fitted.
Detailed recommendations for flue systems are given in
BS 6644, & IGE UP/10. The following notes are intended
to give general guidance only.
The boiler should be connected to a single flue
system in the case of a single boiler, or a common
flue header in the case of a multiple boiler installation.
Flue systems must be self supporting, contain access
for cleaning and contain a maintenance joint near the
boiler outlet to allow for removal of the flue box
during servicing.
6.2Design Waste Gas Volume and Temperature
It is recommended that the volume and temperature
of the waste gases used for design of the flue system
are as shown in Figure B.
6.3 Materials
Materials used for the flue system must be mechanically
robust, resistant to internal and external corrosion, noncombustible and durable under the conditions to which
they are likely to be subjected.
Consideration should be given to possible freezing of
condense water traps and pipework. This must be
avoided at all times. Insulate condense pipes if freezing
temperatures are likely to be encountered.
Chimneys should be lined with a non-porous acidresistant material in accordance with BS 5854,
e.g. a flexible flue liner or similar British Gas
Approved material. The internal diameter of the liner
must not be less than the recommended flue size and
the number of joints should be kept to a minimum.
Any joint between the flexible liner and the flue pipe
from the boiler should be made using a purpose
made connector. Existing chimneys should be
thoroughly swept before use and any register plates,
dampers, or restrictions removed.
If the boiler/s is not connected to a chimney system,
but is connected directly to outside by a standard
stainless steel flue (either single or twin wall) it is
particularly important to ensure that the point at which
it exits the building is fully weatherproofed.
6.4 Suction
The flue system should be designed to maintain
atmospheric pressure or a slight suction at the boiler flue
connection at all times (0.1 - 0.3 mbar).
It is recommended that a draught stabiliser is fitted to the
flue system where the suction is likely to exceed 0.3
mbar.
6.5 Disconnection
Provisions should be made for disconnection of the flue
pipe for servicing. It is advisable that bends are fitted with
removable covers for inspection and cleaning as
appropriate.
NOTE:- The flue system must be self supporting and not
present a risk to people in or around the building.
See Section 13.0: Servicing for further information.
6.6 Flue Discharge
The flue system must ensure safe and efficient operation
of the boiler to which it is attached, protect the
combustion process from wind effects and disperse the
products of combustion to the external air.
The flue must terminate in a freely exposed position and
be situated so as to prevent the products of combustion
entering any opening in a building. Consideration should
be given to the fitting of a flue discharge terminal or grille
to stop the ingress of birds etc.
The flue system should be designed such that the
flue terminates at least 1 metre above the roof
surface, or above the level of any nearby structure
which is within 2.5 metres of the flue.
6.7 Surface Temperature
Combustible materials in the vicinity of the boiler and flue
shall not exceed 65 °C during boiler operation. The flue
shall not be closer than 50mm to any combustible
material, except where it passes through such material
with a non-combustible sleeve when the air gap may not
be less than 25mm.
6.8Flue System Location
The flue system must not be placed or fitted where there
is undue risk of accidental damage to the flue pipe or
undue danger to persons in the vicinity.
NOTE:- The flue MUST be self supporting. Check that
the flue and chimney are clear from any obstruction.
6.9 Condensate Discharge
When designing the flue system, care must be taken
to ensure that any condensate which may form within
the system, can be safely drained to a suitable waste
point and, that the flue material used is resistant to
the corrosive effects of that condensate.
Detailed recommendations for air supply are given in
BS 6644.
The following notes are intended to give general
guidance.
In all cases there must be provision for an adequate
supply of air for both combustion and general ventilation,
in addition to that required for any other appliance.
7.1 Air Supply by Natural Ventilation
The boiler room must have, or be provided with,
permanent air vents directly to the outside air, at high
level and low level.
For an exposed boiler house, air vents should be fitted
preferably on all four sides, but at least on two sides.
Air vents should have negligible resistance and must not
be sited in any position where they are likely to be easily
blocked or flooded or in any position adjacent to an
extraction system which is carrying flammable vapour.
Grilles or louvres must be so designed that high velocity
air streams do not occur within the space housing the
boiler.
The air supplied for boiler house ventilation shall be such
that the maximum temperatures within the boiler house
shall be as follows:
1) At floor level (or 100 mm above floor level) = 25 °C.
2) At mid-level (1.5 m above floor level) = 32 °C.
3) At ceiling level (or 100 mm below ceiling level) = 40°C
Where both low and high level openings are used, the
grilles shall have a total minimum free area of :-
Low Level (inlet) 540cm
²
plus 4.5cm² per kW
in excess of 60 kW total rated input (gross).
High Level (outlet) 270cm
²
plus 2.25cm² per kW
in excess of 60kW total rated input (gross).
7.2 Air Supply By Mechanical Ventilation
Air supplied to the boiler room by mechanical means
should be as follows :-
1) Mechanical inlet and mechanical extract can be utilised
providing design extraction rate does not exceed one
third of the design inlet rate.
2) Mechanical extract ventilation with natural inlet
ventilation MUST NOT be used.
NOTE:- For mechanical ventilation systems an automatic
control should be provided to cut off the gas supply to the
boiler, in the event of failure of air flow in either inlet or
extract fans.
Recommendations for the water circulation system
are given in BS 6644 and CP 342. The following
notes are of particular importance:-
1) In a combined central heating and hot water
system, the hot water storage vessel must be of the
indirect cylinder or calorifier type. The hot water
storage vessel should be insulated preferably with not
less than 75mm (3 in) thick mineral fibre, or its
thermal equivalent.
2) Circulating 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
cavities. Cisterns situated in areas, which may be
exposed to freezing conditions, should also be
insulated. Insulation exposed to the weather should
be rendered waterproof.
3) Drain valves must be located in accessible
positions which permit the draining of the whole
system, including the boiler and hot water storage
vessel.
4) Each boiler has PN6 Flanged flow and return
connections located on the top/ rear section of the
boiler.
5) Multiple boilers should be connected by flow and
return headers. Headers should be connected to the
system in a "reverse return" arrangement (the water
flow in each header is in the same direction) to
ensure equal flow in each module.
Figure F - Cold Feed and Vent Pipe Sizes (mm)
Boiler Output Feed Vent
60kW to 150kW 25 32
150kW to 300kW 32 38
300kW to 600kW 38 50
600kW & above 50 65
8.2 Pressure Relief Valve (Safety Valve)
The most important single safety device fitted to a
boiler is its safety valve and each boiler, or in the
case of a modular installation, each bank of boilers,
must be fitted with a pressure relief valve to BS 759
or BS 6759 Pt.1 (ISO 4126) and sized as shown in
BS 6644.
BS 6644 provides comprehensive information for the
selection and location of safety valves and attention is
drawn to the higher capacity requirements of safety
valves for pressurised hot water systems.
8.3 Open Vent and Cold Feed Pipe
(See BS 6644 for further information.)
Every boiler or group of boilers should have an open
vent pipe and cold feed pipe installed between the
boiler and the first water isolating valve. The
minimum bore (mm) of these pipes per installation is
as follows:-
The vent pipe must rise continually, must not be
valved except by a design which when closed for
maintenance the boiler is open to atmosphere. The
pipe shall be protected against freezing where this
might occur.
8.4 Altitude Gauge (Water Pressure Gauge)
Every boiler or group of boilers should be provided
with a gauge complete with isolating valve. See
Figure A for typical position.
8.5 Thermometer
See Figure A for typical position.
A thermometer complete with pocket should be fitted
in the pipework to indicate water flow temperature.
8.6 Drain Valves
Each boiler should have ¾” NB drain valve fitted (not
H.H.L. supply), to drain the boiler only. A plugged Rc
¾” connection is provided for a drain valve at the
bottom of the front boiler section.
The heating system in total should have drain valves
as recommended by BS 6644. See Figure A for
recommended positions.
One or more circulating pumps will be required to
circulate water around the boilers and heating
system. The pump should be sited to facilitate
servicing. It is also important that the existing system
be flushed through twice to remove any loose matter,
which may have accumulated. If in any doubt
regarding the cleanliness of the system, a coarse
filter should be fitted in the return pipework to the
boilers.
NOTE:- If boilers are run off time clock control, a
pump overrun (not H.H.L. supply) should be fitted
which must run for a minimum of 5 minutes on shutdown of the last boiler.
8.8 Minimum Water Flow Rates
Minimum water flow rates are shown in Figure B.
These flow rates should be maintained through the
boiler at all times whilst the boiler is firing. If the
water flow rate is allowed to fall below the minimum,
the boiler heat exchanger could fail due to the
resultant scale formation. Particular attention should
be paid to the restriction of external flow circuits
during periods of low heat demand.
8.9 Waterside Pressure Drop
The waterside hydraulic resistance (Pressure drop) is
shown in Figure B.
8.10 Control Schemes
8.10.1 Temperature Controls
An adjustable control thermostat is supplied with each
boiler and should be set to operate within the range 6590°C for standard applications. A temperature limiter,
(hand reset limit thermostat) is also fitted to the boiler and
must be set at 100°C.
NOTE:- The minimum difference between control
thermostat and temperature limiter MUST NEVER be
less than 10°C.
Where the system is operating on a ∆T of 20°C, care
should be taken to ensure that the return temperature
does not fall below 50°C.
8.10.2 Water Flow Controls
Any external mixing valve/shunt pump or similar controls
should ALWAYS ENSURE that the minimum water flow
rate as shown in Figure B is maintained.
8.10.3 Frost Protection
Consideration should be given to fitting a frost thermostat
set at approximately 4°C.
8.11 Unvented Systems
See Figure A for typical layout of a Unvented
(Pressurised) Hot Water System.
For system design refer to BS 7074 Pt.2.
In order to correctly size a pressurisation unit for any
heating system certain parameters are required :-
1) Static height of highest component in system
(metres).
2) System volume - if it is not known a general rule of
thumb of 10 litres/kW of installed boiler power can be
used.
3) Maximum flow temperature (°C).
4) Maximum system hot working pressure, generally
given in bar g.
From the above information Hamworthy Heating can
size the pressurisation unit and also the expansion
vessel required. Care must be taken in sizing
expansion vessels to ensure maximum acceptance
factors are not exceeded. Normally manufacturers of
vessels impose a limit of 0.5. This value must not be
exceeded at any time during the operation of the
boiler: this includes the over pressure condition should
a safety valve lift.
Consideration should also be given to sizing of the
safety valve/s in the system.
See BS 6759:Pt.1, for information.
See also BS 6880:Pt.1, for design considerations.
8.12 Modular Boiler Control Schemes
For modular boiler installations, Hamworthy Heating
can supply a unique boiler management control
system called the ‘Marshall HE’. This system
comprises: a wall mounted master control unit, which
houses the main interface processor and will control
up to 8 stages. For further information, contact
Hamworthy Heating for details.
Wiring external to the boiler must be installed in
accordance with the I.E.E Regulations and any local
regulations which apply. Wiring must be completed in
heat resistant cable. (For size, refer to the Technical
Instructions supplied by the burner manufacturer). The
boiler control panel requires a 230V, single phase 50 Hz
supply.
Fuse ratings for individual boilers are marked on the
appliance data plate. The control panel is supplied
with flying lead and plugs for direct connection to
corresponding sockets supplied with the burner.
Should non-standard connecting wiring be
necessary due to particular burners or contract
conditions, space is provided in Appendix A of these
instructions for a wiring diagram to be included.
Note a 3 phase 4 wire (including neutral) supply
is required from which the 3 phase should be
wired direct to the burner with a single phase
and neutral spurred off to the boiler control
panel.
The method of connection to the mains electricity supply
must facilitate complete electrical isolation of the single
boiler/battery with a contact separation of at least 3 mm
in all poles.
The appliance must be isolated from the mains
electricity supply in the event of electric arc welding
being carried out on any connecting pipework.
A mains isolator must be provided adjacent to the boiler
in a readily accessible position. The supply should only
serve the boiler.
NOTE:- Volt free contact electrical supplies must also be
isolatable where fitted (see note in control panel).
Further details regarding connection to the electricity
supply are given in BS EN 60335 Pt.1 or
BS 3456 Pt. 201.
9.2 Indication Signals and Volt Free Contacts
Control panels are fitted with v.f.c.’s (volt free contacts)
to enable external indicator lights or alarms to derive
signals for normal run, overheat and lockout.
NOTE:- These external circuits MUST be isolated
before any service or maintenance procedures are
carried out.
The following procedure should be adopted for the
initial site build of the boiler or following any
dismantling due to maintenance.
10.1 Preparation
The heat exchanger is made up from three
different types of section, each section weighing
around 190 kg. Due to the weight, this operation
should be carried out by two operatives.
1) Check off all materials and parts (see Packing
List Section 1.2) and that a sealant gun and
adequate supply of sealants and primer have been
provided.
Using a clean rag and kerosene, or similar, wipe
the ‘O’ ring grooves and sockets on each section
prior to assembly. Clean all sealing grooves on the
casting face with a wire brush and apply the primer
liquid using the applicator bottle provided.
Important:- Allow the primer to dry prior to applying
the sealant (10 mins).
WARNING:- the sections are not self supporting
until several sections have been assembled
together. Precautions should be taken to
adequately support sections to prevent injury or
damage. Ensure that the position of the sections is
aligned with the intended water and flue
connections during assembly.
2) Select the rear and intermediate section and
apply a bead of silicone rubber compound, 5mm
proud, around each of the two outer sealing
grooves, of the mating faces.
Apply boiler cement to the inner sealing groove
mating faces.
3) Position the sections on the plinth, fit the guide
and ‘O’ rings to the top and bottom sockets of the
rear section. These may require careful tapping
into position using a mallet.
Position the intermediate section directly in front of
the rear section, and using a crow bar under the
bottom of the intermediate section, gently lift the
intermediate section to engage the upper guide
ring and then manoeuvre onto the lower guide ring.
4) Insert the four tie bolts through the securing lugs
and tighten diagonally to ensure an even pull up on
the guide rings until a face to face contact has
been achieved. A maximum torque of 20N/m
should be applied. Alternate the tie bolts between
upper and lower fixings on adjacent sections.
Only work with one section at a time when pulling
together.
Smooth over the sealing compound to leave a
clean bead but slightly proud of the casting.
5) Complete the boiler build by repeating steps 1-4.
Once all waterway sections have been assembled,
prepare the rear section and flue cover casting by
applying primer and silicone to the outer grooves.
Secure the flue cover to the rear section using tie
bolts.
6) Fitting the Inserts
WARNING: THE INSERTS MUST BE
INSTALLED BEFORE THE BURNER IS FIRED
OTHERWISE DAMAGE MAY OCCUR TO THE
FLUE SYSTEM DUE TO HIGH EXHAUST GAS
TEMPERATURES.
NOTE: Insert dimensions vary depending on
boiler size. Ensure correct length tube is used
prior to assembly.
a) Install the inserts with the pointed end,
incorporating the removal ring, pointing towards
the front of the boiler whilst ensuring that inserts
are pushed fully back.
b) The inserts must be positioned to ensure that
they sit on the support feet. If the inserts are not
correctly installed burn out may occur.
7) Fit the boiler flow and return connections and
cap off with blanking plates and gaskets, leaving a
suitable fitting on top of the rear section to enable
venting during filling and testing. Fit a drain
connection to the lower flange on the front section.
8) On completion of assembly, the heat exchanger
should be hydraulically pressure tested to 1.5 times
the maximum system pressure for 30 minutes
(BS779 - 1989, Amendment 1 - 1993).
9) Check carefully for any leaks, and if satisfactory,
drain the boiler sections and remove the blanking
plates.
10.2 Dismantling
IMPORTANT:- the boiler sections are not self
supporting, particularly when there are only a few
sections remaining.
During dismantling, the sections must be
supported to prevent injury or damage.
Dismantling the boiler is the reversal of the
assembly procedure. Inserts should be removed
using removal tool provided.
Installers must ensure compatibility between boiler
body and burner by referring to Figure M. If in any
doubt, contact Hamworthy Heating for assistance.
Picture 1: Completed Build
Items Required for Build:
M10 x 40 Stud 6 Off
M10 x 20 Screw 3 Off
M10 Nut 4 Off
Pin 50 mm Long 12 Off
Control Panel Bracket 2 Off
Pack of Self-Tapping Screws Accessory Pack
Tools Required for Build:
Stanley Torx T25 Screwdriver or equivalent
Ø10 mm Round File
Ø4 mm Drill Bit & Drill
Spanners 17 mm A/F & 36 mm A/F
Gloves etc for handling Fibreglass
Note: In general the casing panels will be drilled
ready for the self-tapping screws, thus the build
instructions will assume all aligning holes will be
locked together with these screws unless otherwise
stated.
10.3.1 Fitting of Door & Front Casings
Attach and tighten the four hinges (Items 15 to 18 &
62 to 64) to the front section. Fit the locknuts to the
studs on the hinge side.
Picture 2: RH Front Casing Fitted incl. Door
Fit the six hexagonal spacers to the front section and
fit the LH & RH boiler front casing (2-piece
construction) using the screws provided.
Position the hinged door casting for left or right
opening. The two smaller of the four door fixing holes
should be positioned on the hinge side. Using a jack,
raise the door to align with the hinge brackets and
engage the door holes with the appropriate hinge
studs. Fit and tighten the fixing screws.
Close the door and fasten with the door securing
nuts, open it, then check the impression of the sealing
grooves in the braiding. There should be a uniform
impression approximately 2mm in depth. Adjust the
fixing nuts to obtain the correct impression. Tighten
all fixings diagonally to ensure an even seal between
the door and front section.
Fit the Insulation over the rear section , then fit the LH
& RH boiler rear casing (2-piece construction). These
are located with the Inspection Doors and Flue
Connection Spigot. Ensure that the Flue Gasket is
used. Lock to position using 3 off M10 X 20 Long
screws and 2 off self– tapping screws.
Picture 3: RH Rear Casing Fitted
Fit the lower rear casings (2-piece construction) as
shown using 1 off self-tapping screw each side.
Picture 5: Boiler Body Insulation
Note: It may will be necessary to trim the length of the
insulation to suit therefore suitable protective apparel
should be worn. (see Section 1.5)
Picture 6: Side Rail attachment.
Due to the sectional nature of the Boiler the Side
Rails are supplied as 2 `L` shaped brackets, on larger
boiler sections, which slide over one another to
achieve the required length. When the Front and
Rear Covers are in place these brackets should be
Picture 4: Lower Rear Casings
10.3.3 Boiler Body Insulation & Side Rails
Place the boiler body insulation over the sections and
draw down equally on both sides to the base of the
boiler. Make good any joints with the tape provided.
The insulation should be cut-out around the front and
rear top connection flanges.
attached on both sides using 2 off Self-Tapping
Screws into the slotted holes. It will then be
necessary to drill 4 off Ø4mm holes to attach these
brackets together with an additional 4 off SelfTapping Screws; these should be drilled through the
existing Ø4mm holes on the brackets.
Note: It is easier to fit the top Side Rail, then to move
it to the bottom position to achieve correct length
matching.
Starting from the Rear the first side plate should be
hung over the Top Side Rail and attached to the Rear
Cover using 4 off Self-Tapping Screws. These will
require drilling Ø4mm.
This should be repeated towards the front until all
side panels are in position as shown.
10.3.5 Top Panel Mounting
Picture 8: Top Rear Plates
Attach the Rear Top Plate using 4 off Self-Tapping
Screws. Position the 2 Rear Flange Top Plates as
shown but do not secure, the Top Covers should be
fitted from the front.
Note: It may be
necessary to file the
Rear Flange Top Plates
as shown to fit, due to
interference with the
riser connection.
Picture 9: Top Cover Complete
Fit the Front Top Cover as shown using the Control
Box as a guide to how far forward this plate should
extend. This Control Box may be fitted at this time if
required (see section 10.3.8).
Then fit top cover sections in turn from front locking
them into position with Self-Tapping Screws drilled to
position, as required.
10.3.6 Door Insulation
Picture 10: Door Casing Insulation
Fit the Door Casing Insulation by pushing onto the 4
off M10 x 40 Studs. Place the upper and lower Back
Insulation pieces to position and pin using the 50mm
Pins provided.
The two side Insulation Pieces should also be
similarly located.
Locate the door casing with the Burner Flange
Mounting Screws then lock to position using the
M10 bolts, spacer and the M10 nuts. Fit the Sight
Glass assembly.
10.3.8 Control Box Fitting Procedure
Picture 12: Control Box
Fit the Control Box to position using 6 off SelfTapping Screws, 4 along the top and 2 at bottom
as shown.
Fit the Control Box Cover.
10.3.9 Control Panel Fitting Procedure
Picture 13: Control Panel Attachment
Fit brackets to control panel using 4 off M5 x 12
pozi screws. Position the assembly on the
casing top panel, mark positions of the 4 fixing
holes. Remove Control panel assembly and drill
4 holes 3mm dia. in casing. Place Control Panel
assembly in position and secure with 4 off SelfTapping Screws.
The control panel fascia can now be hinged
down by unlatching the catch on the top right
hand using a screwdriver. NOTE: before
attempting to hinge the fascia down, the
thermostat knobs must be pulled off and the
temperature limiter (high limit) cover knob
unscrewed and removed.
With the fascia hinged down, the terminals are
exposed and the power supply can be
connected to the appropriate terminals via the
glands in a removable plate at the bottom right
hand side. The upper front casing panel has a
cut out appropriately positioned beneath the
gland plate to allow the power supply cables to
enter the casing and to allow the flying leads to
the burner to exit.
A powered lock-out terminal and a remote
control link C1-C2 are also provided together
with an optional volt-free contact kit (see Fig G
on page 14 of this manual) the terminals being
adjacent to the power supply, and cables for
these functions should be run in a similar
manner. For remote control remove the wire link
between C1-C2 and replace with control cables.
If the panel is for High/Low burners an additional
link C3-C4 is also supplied, removal of which
holds the burner on low fire. This link can also
be replaced by control cables if remote high/low
operation is required. For ease of disconnection,
the terminals used are of the plug and socket
type and hence all external wiring can be easily
removed by pulling the top half of the terminal
rail upwards and threading cables through the
gland plate once removed.
Depending on the type of burner fitted, the panel
will provide a single flying lead terminating in a
seven pin plug for connection to an on/off
burner, or an additional flying lead terminating in
a four pin plug for connection to a high/low
burner. The panel for a high/low burner will also
have an additional thermostat, hours run meter
and run lamp.
When wiring is complete, raise hinged fascia
and click into position by pushing on latch screw
and replace thermostat knobs. Finally, locate
control panel cover on brackets and secure with
M5 nuts and shakeproof washers.
A burner mounting plate is supplied with each boiler
specific to the burner requested. Fit the plate to the
front door casting using four M12 countersunk
screws. Secure the burner and gasket to the burner
mounting plate using the four bolts supplied with the
burner.
IMPORTANT: BEFORE SECURING THE BURNER
MOUNTING PLATE TO THE FRONT DOOR
CASTING, APPLY MASTIC TO THE RIM OF THE
BURNER APERTURE ON THE CASTING. FAILURE
TO SEAL THIS JOINT WILL RESULT IN LEAKAGE
OF FLUE PRODUCTS AND HEAT STAINING OF
THE SURROUNDING CASING PANELS.
Having secured the burner to the mounting plate,
apply the Cafco Blaze burner sealant between the
burner blast tube and door refractory lining. The
compound should be gradually mixed with water until
pliable ( the 2kg pack requires 4 litres of water). It is
essential that the gap is filled and that the mix has
been compressed and finished flush with the inner
face of the door refractory lining.
Check that the weight of the burner has not affected
the sealing of the door, especially after several
opening and closings operations. Larger burners
should be supported independently with a suitable
device whilst still allowing the door to open.
NOTE:- All cables must exit the control via the cutouts in the bottom and must be routed adjacent to
the burner mounting plate.
The cables MUST NOT be routed across the
burner or it’s mounting plate.
Following completion of the boiler assembly, the
cleaning and assembly tools should be left on site in
a safe place, preferably within the boiler room.
11.0 COMMISSIONING AND TESTING
11.1 Electrical Installation
Wiring MUST be checked by a suitably competent
person. Power supply required is 400V 50 Hz three
phase, 4 wire. An isolator correctly fused should be sited
close to the boiler. Refer to the burner instructions.
It should be noted the 3 phase supply should be
wired direct to the burner and a separate 240V
single phase supply derived from the burner
should be wired to the panel.
The boiler is supplied with a remote stop/start circuit for
time clock operation. Any other interlocks, i.e.
Pressurisation unit, BEM System should be wired in
series with the remote stop/start loop.
11.2 Gas Installation
For design see Section 5: Gas Supply.
The whole of the gas installation including the meter must
be inspected and tested for soundness and purged in
accordance with the recommendations of IGE/UP/1 or
IGE/UP/1A as appropriate.
11.3 Water Circulation System
For design see Section 8: Water System.
The system should be thoroughly flushed out with cold
water without the pump in position. Ensure all the valves
are open.
With the pump fitted the system should be filled and air
locks cleared. Vent the radiators and check for leaks.
If the system is unvented the pressurisation unit should
not be utilised for the initial filling. This should be carried
out using a WRC approved double check valve and
temporary filling loop. In order to comply with local Water
Authority Regulations, this loop must be disconnected
when filling is complete. Water treatments should not be
fed through the pressurisation unit unless permitted by
the manufacturer. Check the expansion vessel cushion
pressure as detailed by the manufacturer's Installer's
Guide.
11.4 Commissioning The Boiler
Only competent persons registered for working on
non domestic gas appliances should attempt the
following: Before attempting to commission any
boiler, ensure that personnel involved are aware of
what action is about to be taken and begin by making
the following checks:-
1) Flue way passages to chimney are clear.
2) Adequate ventilation as per Section 7: Air Supply
3) The system is fully charged with water, ready to
receive heat. All necessary valves are open and the
pump is circulating water.
4) The pipework and valve arrangement is installed to
Hamworthy Heating recommendations in such a way that
water flow rates will be in accordance with Figure B.
5) The gas supply pipework is clear of any loose matter,
tested for soundness and purged to IGE/UP/1 or
IGE/UP/1A as appropriate.
11.4.1 Boiler Checks Prior To Lighting
BEFORE starting the boiler, check the following:
a. Check that fuel supply is turned off.
b. Check that electrical supply is isolated.
c. Check that electrical installation conforms to the
requirements of these Instructions, the IEE Wiring
Regulations for electrical installations, and any other
local Regulations which apply.
d. Check boiler castings are undamaged Remove
access plates to check flue inserts are fitted.
e. Check all thermostat bulbs are correctly inserted
in the appropriate pocket.
f. Check for water leaks and ensure that both boiler
and heating system is full of water and properly
vented.
g. Check that all drain cocks are closed, and that all
isolating valves in flow and return pipework are open.
h.For OIL; check that tank/s have been filled and oil
supply pipework between tank and burner has been
primed.
j.For GAS; check soundness of gas installation and
that pipework is purged of air, as detailed in British
Gas Publications IM/5 and IM/2 respectively.
Check that gas meter is operational and has been
checked by the local region of British Gas.
Check that gas meter and supply pipework is of
sufficient size to meet the input rating of the burner/
boiler. Refer to Section 2.1.
k. Check that burner output is correct for size of boiler
in question, referring to Figure M, and the
manufacturer's technical information supplied with the
burner.
NOTE: - ALL FUELS. Refer to the commissioning
procedure in the burner manufacturers literature,
before firing the boiler.
Always adjust the fuel supply upwards from a low
position to ensure that a fuel rich mixture is not
achieved.
11.4.2 Oil fired Boilers
a. Check flexible oil lines are tightly jointed and are
not twisted or kinked to form an obstruction.
b. Check correct nozzle/s is fitted to burner (Fig 11.4)
and that it is tight.
NOTE:- Some burners are despatched with a test
nozzle/s fitted. In these cases, the correct nozzle/s is
despatched in a separate package with the boiler and
MUST be fitted to the burner before attempting to fire
the boiler.
c. Check electrodes and ensure porcelain insulation
is not cracked.
d. Check electrodes are correctly positioned, and
gap is correctly set, as specified in the manufacturer's
technical information supplied with the burner.
e. Check blast tube is correctly located, and
securely fastened in place and firebrick at rear of
combustion chamber is sound and correctly located.
.f. Check burner seats correctly onto burner
mounting plate and is securely fastened in place.
g. Set burner for the required fuel and air
throughputs, as specified in the manufacturer's
technical information supplied with the burner.
h. Fit a pressure gauge on burner oil pump to check
pump pressure is correctly set.
i. Check that overheat thermostat manual reset is
set, and that boiler control thermostat and control
system are set to call for heat.
Switch the boiler on and start the burner.
j. The burner control will first operate the fan to prepurge the boiler, then produce an ignition spark and
finally open the oil solenoid valve and the flame
should ignite.
k. Purge air from oil pump through pressure gauge
port.
IF BURNER LOCKS OUT WAIT 45 SECONDS
BEFORE PRESSING RESET BUTTON ON
BURNER CONTROL BOX.
l. With burner firing, check the atomising pressure on
gauge and adjust as necessary using the pressure
regulator on burner oil pump. Refer to technical
information supplied with burner.
m. After allowing burner to reach stable firing
conditions for approximately 15 minutes, carry out
combustion gas check.
Measure CO
, CO, smoke number, flue gas
2
temperature and circulating water temperature rise
across the boiler. The readings obtained should be as
indicated in Figure O, target appliance readings.
Readings should be taken at both High and Low
settings. A link 20-22 is provided in the control panel
terminals, the removal of which, will hold the burner
on low fire.
n. Switch off boiler. Remove oil pressure gauge and
replace sealing plug complete with gasket.
o. Restart boiler and cycle it on and off several times
to ensure reliable burner ignition and boiler operation.
Check for oil, water and flue gas leakage. Tighten all
access flue box and burner mounting bolts and nuts.
p. Set boiler control thermostat to required setting,
and check operation of heating control system.
q. Fully familiarise the user with the boiler operating
controls, the main component functions and the
safety features.
THESE INSTALLATION AND SERVICING
INSTRUCTIONS SHOULD BE LEFT WITH THE
USERS OF THE BOILER FOR THEIR FUTURE
REFERENCE.
11.4.3 Gas fired Boilers
a. Check that ignition electrode and rectification
probe are correctly positioned. Refer to
manufacturer's technical information supplied with the
burner.
b. Check that ignition electrode and rectification
probe leads are connected.
c. Check blast tube is correctly located, and securely
fastened in place.
d. Check burner seats correctly onto burner mounting
plate and is securely fastened in place.
e. With firing head separate from burner adjust air
and gas settings, as specified in the manufacturer's
technical information supplied with the burner.
f. Determine minimum burner gas pressure which
corresponds to required burner output (boiler input),
as follows:
From the manufacturer's technical information
(supplied with the burner) take burner pressure
corresponding to required burner output.
Add combustion resistance (in mbar), given in Figure
D for the boiler in question, to obtain gas pressure
value to be measured at burner test point.
g. Open main isolating valve in gas supply to boiler.
Check for leaks throughout gas train and pipework to
burner.
h. Adjust gas supply governor to achieve at least
17.5 mbar (7.0 in.wg.) at inlet to boiler gas train.
Ensure that maximum pressure of gas train governor
is not exceeded. If a gas booster is to be fitted,
commission in accordance with the manufacturer’s
instructions.
i. Adjust start and main output gas rates as detailed
in the manufacturer's technical information supplied
with the gas burner.
j. Check that overheat thermostat manual reset is
set, and that boiler control thermostat and control
system are set to call for heat.
k. Close main isolating valve in gas supply, switch
the boiler on and start the burner. The burner control
will first operate the fan to pre-purge the boiler, then
produce an ignition spark and attempt to ignite the
burner. The flame should fail to ignite and the burner
should go to lockout.
l. Open main isolating valve in gas supply. If gas
train has separate pilot gas line, open pilot gas
isolating valve and close main gas isolating valve.
Restart boiler/burner. The burner control will prepurge, produce an ignition spark and ignite pilot
flame. The main flame should fail to light, and burner
will continue running on ignition flame only. The pilot
gas rate can be checked and adjusted as detailed in
the manufacturer's technical information supplied with
the gas burner.
IF BURNER FAILS TO LIGHT, BOILER MUST BE
PRE-PURGED BEFORE ATTEMPTING TO
RESTART BURNER. IF BURNER REPEATEDLY
FAILS TO LIGHT, A FULL INVESTIGATION TO
FIND CAUSE SHOULD BE MADE.
m. Stop boiler/burner. Open main gas isolating valve
and restart burner. The burner will pre-purge, ignite
pilot flame and, after a short delay of several
seconds, the main flame will light. Adjust the main
gas rate as detailed in the manufacturer's technical
information supplied with the gas burner.
n. After allowing burner to reach stable firing
conditions for approximately 15 minutes, carry out
combustion gas check.
Measure CO
, CO, flue gas temperature, and
2
circulating water temperature rise across the boiler.
The readings obtained for the appropriate gas should
be as indicated in Figure O, target appliance
readings.
Readings should be taken at both High and Low
settings. A link 20-22 is provided in the control panel
terminals, the removal of which, will hold the burner
on low fire.
o. After all other adjustments have been made, set
burner air pressure switch as instructed in
manufacturer's technical information supplied with
burner.
p. Check gas pressure at burner head corresponds
with value determined from burner manufacturer's
technical information - as detailed in (f) above.
q. Check gas flow rate at meter. Ensure that all
other appliances served by the meter are isolated
whilst flow rate is checked.
r. Cycle boiler on and off several times to ensure
reliable burner ignition and boiler operation. Check
for gas, water and flue gas leakage. Tighten all
access, flue box and burner mounting bolts and nuts.
s. Set boiler control thermostat to required setting,
and check operation of heating control system.
t. Fully familiarise the user with the boiler operating
controls, the main component functions and the
safety features.
THESE INSTALLATION AND SERVICING
INSTRUCTIONS SHOULD BE LEFT WITH THE
USER OF THE BOILER FOR FUTURE
REFERENCE.
11.5 External Controls
The external controls used in typical boiler
installations, for both vented and unvented systems,
are shown in Figure A. If different systems or controls
are to be used and there are any doubts as to the
suitability, contact Hamworthy Heating Technical
Department for advice.
11.6 Installation Noise
In order to avoid the possibility of noise from the
installation, care should be taken to follow the
manufacturer’s instructions. Particular attention should be
paid to minimum water flow rates. If acoustic insulation is
added to the boiler, care must be taken not to impede
combustion or ventilation air flow. If in doubt contact the
manufacturer.
11.7 User Instructions
When the above is complete, the boiler owner or their
representative should be made aware of the lighting and
operating instructions . A practical demonstration should
be given describing each functional step. This Installer's
Guide and burner Operating Instructions should then be
handed over and kept in a safe place for easy reference.
12.0 FAULT FINDING
Fault finding on the burner control system is detailed
in the burner manufacturers instructions. If the boiler
still cannot be operated satisfactorily after following
these instructions, consult Hamworthy Heating for
assistance.
13.0 SERVICING
A qualified engineer registered for working on non
domestic gas or oil appliances should check and ensure
that the flue, its support and terminal, the ventilation to the
boiler house, safety valve, drain, water filter if fitted,
pressure gauge, etc.; are in a serviceable and working
condition and still comply with the relevant standards and
codes of practice - see Section 3.1.
The boiler should be serviced at regular intervals, not
exceeding SIX months for oil fired boilers, or
TWELVE months for gas fired boilers.
When carrying out boiler servicing always consider
both your own safety and that of others. The use of
protective equipment (e.g. eye protection, face mask,
protective gloves, etc.) is recommended where
necessary.
13.1 Initial Inspection
a. Operate boiler and check for any signs of
unsatisfactory operation, water leaks, gas leaks, oil
leaks or unusual noise from burner oil pump or motor.
b. After allowing burner to reach stable firing
conditions for approximately 15 minutes, carry out
combustion gas check.
Measure CO
, CO, flue gas temperature, smoke
2
number (for oil) and water temperature rise across
the boiler. The readings obtained should be noted for
reference upon completion of the servicing
procedure.
c. Measure either gas pressure at burner head, or oil
pressure at burner pump, as applicable, and check
value is correct for size of boiler in question.
d. Check operation of both boiler and heating system
controls, then set boiler control thermostat to OFF.
Allow the boiler/burner to cool.
SWITCH OFF ELECTRICAL SUPPLY TO BOILER
AT ISOLATOR AND SHUT OFF FUEL SUPPLY TO
BOILER.
Clean and service the burner in accordance with the
burner manufacturers instructions.
a. Disconnect electrical and fuel connections to
burner, as necessary.
b. Disconnect burner from the fuel supply and open
the hinged door, with the burner attached.
13.3 Boiler Service Procedure
a. After hinging the burner, remove boiler casing,
control panel (taking care to remove thermostat
bulbs) and front insulation to gain access to front
section of boiler. The power supply to the control
panel and additional control cables, if used, must be
disconnected.
b. Boiler combustion chamber and heat exchanger
flueways are now accessible for cleaning with the
brush and a vacuum cleaner once the flue inserts
have been removed.
c. Access to rear of heat exchanger flueways and
combustion chamber can be obtained by removing
the access covers from rear of boiler.
d. Replace all access/cover plates, ensuring that all
gaskets and insulation panels are correctly fitted.
Refit securing studs/nuts and tighten evenly.
e. Refit boiler insulation, casing and control panel
(ensure thermostat bulbs are correctly located in
pocket). For guidance, refer to Section 10.
f. Refit burner. Reconnect fuel and electrical
supplies.
g. Turn on fuel supply and check soundness of fuel
supply pipework.
h. Check all flue joints for integrity.
i. Check ventilation ducts/grilles to boiler room and
ensure they are clear.
j. Re-commission boiler as detailed in relevant parts
of Section 11.0: Commissioning & Testing.
14.0 REPLACEMENT OF PARTS
There are a number of components listed below which
can be replaced simply and quickly by following the given
procedure. In each case the operation of each replaced
component must be checked by carrying out the
appropriate part of the commissioning procedure.
See Section 11.0: Commissioning & Testing..
NOTE:- Isolate all electrical supplies to the boiler and
turn off the gas supply before removing controls
cover and commencing any servicing or component
exchange procedure.
NOTE:- For replacement of burner components refer
to the burner manufacturers instructions.
14.1 Control and High/Low Thermostat/s
Record the existing temperature setting of the
thermostat for reference before removal.
NOTE:- Before removing the control panel top, the
thermostat knobs must be pulled off and the
temperature limiter (high limit) cover knob unscrewed
and removed.
Withdraw the appropriate thermostat bulb from the
thermostat pocket and disconnect the electrical
connections noting the terminal identifications.
Remove the two screws securing the thermostat to its
mounting bracket and withdraw the thermostat body
whilst feeding the capillary through the hole in the
control panel mounting plate.
Fit the new thermostat and ensure the capillary is
correctly located within the thermostat pocket. Close
the fascia and run the boiler to check for correct
operation. Set the thermostat to the previously noted
setting.
14.2 Temperature Limiter (Limit Thermostat)
The temperature limiter replacement procedure
follows that of the control thermostat with some minor
differences as detailed below:
With the plastic cover removed, unscrew the holding
nut and carefully withdraw the thermostat body
Prior to fitting the replacement thermostat, set to
100°C and check the operation of the device by carefully
applying a heat source to the bulb.