Potterton NXR4 Instruction manual

NOVEMBER 2003
heating specialists

Fig. 1 – General Data & Dimensions (all dimensions in mm)
Table 1 – Boiler Dimensions
NXR4 Type 409 410 411 412 413 414 415 416 417
Amm 1640 1780 1920 2060 2200 2340 2480 2620 2760
Bmm 1440 1580 1720 1860 2000 2140 2280 2420 2560
ØD mm 300 350
Table 2 – Combustion Chamber Data
Model 409 410 411 412 413 414 415 416 417
Mean Diameter mm 525
Cross Sectional Area m20.216
Length (X) mm 1120 1260 1400 1540 1680 1820 1960 2100 2240
Volume m30.24 0.27 0.30 0.33 0.36 0.39 0.42 0.45 0.48
Surface Area m22.06 2.28 2.51 2.74 2.97 3.20 3.43 3.66 3.89
Resistance/Pressure mbar 1.5 2.1 2.2 2.8 3.3 3.3 4.5 5 6
Flue Gas Temperature (Gross) °C 180
Efficiency All Fuels (Nett) %92
(Gross) %83
Percentage CO2 Oil %12
Gas % 9
450
1295
1511
1070
700
X
ØD
400
35
PN 16 125mm
Mating Flange.
732
497
A
B
PN16 125mm
Mating Flanges
140
1098
3/4" Drain
Valve
Front RearSide
POTTERTON COMMERCIAL PRODUCTS DIVISION SECTION 1
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 1
NXR4

Table 3
Model 409 410 411 412 413 414 415 416 417
CE Number 0085AQ0752
Output kW 320 380 440 500 560 620 680 740 800
1Fuel Gas m3/hr 36 42.7 49.4 56.1 62.9 69.7 76.4 83.2 89.9
Consumption Oil lit/hr 35.7 42.4 49 55.7 62.5 69.1 75.8 82.5 89.2
Input (Net) Gas kW
Oil kW
347.6 412.4 477.2 542.1 607.8 672.7 737.5 803.2 868.1
Input (Gross) Gas kW
Oil kW
386 458 530 602 675 747 819 892 964
Maximum Design
Pressure Bar 6 BAR ALL MODELS
2Minimum Operating
Pressure Bar 1 BAR ALL MODELS
3Nominal Flue
Connection Ømm 300 350
4Flue Gas Volume Gas
Oil m3/hr 472 560 648 736 825 914 1002 1091 1179
Flue Draught
Requirements Balanced
5High Level Natural
Ventilation to BS6644 cm2997 1159 1321 1482 1644 1806 1967 2129 2291
5Low Level Natural
Ventilation BS6644 cm21995 2318 2641 2965 3288 3611 3935 4258 4581
6Mechanical Ventilation m3/sec 0.425 0.504 0.583 0.662 0.743 0.822 0.901 0.981 1.06
7Water Connection Size BSP 5” (125mm)
8Water Flow at 11°C ∆tlit/sec 6.93 8.23 9.52 10.82 12.12 13.42 14.72 16.02 17.32
8Hydraulic Resistance at
11°C ∆tkPa 1.56 2.16 2.84 3.61 4.46 5.39 6.42 7.51 8.68
9Cold Feed Size to BS
6644 Min Bore mm 38 50
9Open Vent Size to BS
6644 Min Bore mm 50 53 55 58 60
9Safety Valve Size to BS
6644 Nominal Bore mm 25 32 40 50 65
Maximum Flow
Temperature °C 90°C ALL MODELS
10 Minimum Return
Temperature °C 55°C ALL MODELS (DIRECT COMPENSATED)
11 Dry Weight kg 1589 1745 1884 2028 2166 2315 2445 2585 2725
Water Content kg 302 334 366 398 430 462 494 526 558
Power Requirements Boiler Control Circuit 240V 1Ph 50Hz, Fused 6.3A
See page 3 for explanatory notes Conversion table on inside of back cover
SECTION 1 POTTERTON COMMERCIAL PRODUCTS DIVISION
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 2
NXR4

1 FUEL CONSUMPTION
Gas fuel consumption is based on natural gas with a
gross calorific value of 38.6MJ/m3. The gas rate
should be corrected for meter supply pressure
particularly on high pressure supplies to prevent
overfiring.
Fuel oil consumption is based on Class D (35
second) gas oil with a calorific value of 58.24 MJ/lit
and a density of 0.855 kg/lit, Kerosene (Class C2)
has a calorific value of 53.22 MJ/lit and a density of
0.795 kg/lit.
2 MINIMUM OPERATING PRESSURE
This is the minimum operating pressure of the boilers
with pumps operating (NOT static pressure). The
requirements of the Health & Safety Executive
guidance note PM5 regarding maximum operating
temperatures should be observed.
3 BOILER FLUE CONNECTION
This is the nominal flue size of the flue connection
spigot, for dimensional details of the flue connection
spigot see Fig.1. Actual flue size required to achieve
correct draught and operation under all running
conditions may need to be increased.
4 FLUE GAS VOLUME
Flue gas volumes are given at STP (standard
temperature and pressure [15°C and 1013.25 mbar]).
Typical flue gas temperatures are given in Table 2.
5 NATURAL VENTILATION
The sizes indicated are free grille areas and are
based on a single boiler installation.
6 MECHANICAL VENTILATION
The volume given is for a single boiler installation.
7 CONNECTION SIZES
The boiler water connections are flanged with 5”
PN16 welded counter flanges provided.
8 WATER FLOW RATES
Water flow rates are given for boiler flow and return
temperature differences of 11°C.
9 COLD FEED/OPEN VENT/SAFETY VALVE
SIZES
Sizes indicated are minimum sizes for single boiler
installations.
10 MINIMUM RETURN TEMPERATURE
If system return temperatures below 55°C are
required then contact the Potterton Commercial
Technical Department.
11 WEIGHT
The dry weight is exclusive of the burner and gas
train. Each section measures approximately 1220mm
(high) x 860mm (wide) x 150mm (deep) and weighs
135kg (front), 142kg (inter), 160.5kg (rear).
ANY PERSON OR PERSONS MOVING OR
LIFTING SHOULD BE TRAINED IN MANUAL
HANDLING TECHNIQUES AND IF NECESSARY
USE SUITABLE LIFTING EQUIPMENT TO REDUCE
THE RISK OF INJURY TO THEMSELVES OR
OTHER PEOPLE.
POTTERTON COMMERCIAL PRODUCTS DIVISION SECTION 1
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 3
NXR4

CLEARANCES
The minimum boiler room clearances for access, erection and maintenance are given in Fig.2 and Fig.3, the
dimensions are minimum values. There is no minimum clearance above the boiler, however, it is recommended
that clearance is left above the top of the instrument panel to facilitate its removal. At the front of the boiler allow as
a minimum the A dimension, this is to allow access to the combustion chamber for maintenance and servicing. For
P dimension please refer to relevant burner card.
Fig.2 – Boiler Clearances
Minimum Clearance (Front)
Nu-Way Oil Nu-Way Gas Riello Oil Riello Gas EOGB Oil EOGB Gas
Model A (mm) A (mm) A (mm) A (mm) A (mm) A (mm)
409 1580 1733 1555 1725 1807 1810
410 1580 1733 1555 1725 1807 1810
411 1580 1733 1600 1725 1807 1810
412 1580 1733 1600 1785 1807 1810
413 1542 1885 1610 1785 2086 2296
414 1542 1885 1610 1785 2086 2296
415 1542 2183 1610 2000 2086 2296
416 1686 2183 1950 2000 2086 2296
417 1686 2183 1950 2100 2086 2296
Fig.3 – Boiler Footprint/Base Details
No special plinth is required for
this boiler, a simple dry base is
sufficient. Boiler footprint and
base clearance details are given
in Fig.3.
700
500 min
P + 200
P
A
AB
150mm x 6mm Flat
Plate (Not Supplied
by Potterton)
1070
450
409 410 411 412 413 414 415 416 417
A1320 1460 1600 1740 1880 2020 2160 2300 2440
B1540 1680 1820 1960 2100 2240 2380 2520 2660
Provision must be made to allow free movement of the boiler on
its base.
*NOTE: Base MUST NOT protrude from rear of boiler.
SECTION 1 POTTERTON COMMERCIAL PRODUCTS DIVISION
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 4
NXR4

General
This boiler is NOT SUITABLE for installation in a
normally occupied area (i.e. kitchen)
A LIFETIME GUARANTEE is available on this boiler
please refer to our standard terms and conditions for
details.
The Potterton NXR4 is a cast iron sectional boiler
available in outputs from 320kW (9 – sectional
model) to 800kW (17 – section model). The heat
transfer surfaces of the NXR4 have been specially
designed to maximise the boiler efficiency and the
large combustion chamber capacity ensures
environmentally sound combustion reducing CO and
Nox emissions. Specially designed and prewired
control panels allow full boiler control and flow and
return manifolds have facilities to fit sensor pockets
for boiler management.
The NXR4 is suitable for running at variable low
temperatures under direct compensated control.
The boiler has match tested package burners,
available for Natural Gas, 35 Second & 28 Second
Oil. Dual Fuel options are also available. The
package burner is supported by the front waterway
section to which it is attached by hinges on one side
and locking nuts on the other. Hinge points are
interchangeable allowing for left or right hand door
opening by turning the door assembly through 180°
at the erection stage.
The NXR4 is suitable for use on fully pumped open
vented systems or a sealed system with a maximum
design pressure of 8-bar (116 p.s.i.).
The NXR4 is an overpressure type with 5-pass
reverse flame design. The first two passes are in the
combustion chamber the rest in the convection tubes
where turbulence to achieve high heat transfer is
generated by the extended surface area achieving
efficiencies of 92% (net), 86% (gross).
The NXR4 is constructed with BS1452 Grade220
cast iron heat exchanger, constructed in accordance
with EN303.1. The boiler package meets Gas and Oil
requirements of M&E3 and the burners EN767.
The waterway sections are joined by cast taper
nipples and secured with tie rods. The combustion
chamber is sealed by boiler cement and silicone.
The powder coated mild steel casings have a 50mm
fibre insulation in the casing plus a 50mm fibre wrap
around the castings, thus reducing fuel consumption
and emissions.
The NXR4 is supplied unassembled.
Standard Supply
•Unassembled cast iron sections (number
dependent on boiler output).
•Smoke box, optimising baffles, flueway door,
combustion chamber door, burner adapter plate,
flanged flow and return connections.
•Boiler wrap around insulation
•Insulated casing
•Cleaning brush
•Flow manifold complete with sensor pocket ¾”
screw socket and plug
•Eco – control panel
•Burner
Controls
The NXR4 range is supplied as standard with an
integral control panel which is fitted with, hours run
meters, flue thermometer, on/off control and high/low
stats, limit stat, water stat, reset button, high
temperature warning light, mains on/off light and
fuse.
A 240V single phase supply is taken to the control
panel. A 415V three phase supply should be taken to
the burner motor connections.
Optional Extras
•Volt free contacts
•Sequence Controls
Shipping – Packaging
The boiler package is delivered unassembled on two
pallets with the burner separately either in a carton or
pallet.
Pallet 1
Unassembled sections and door.
Pallet 2
Casing pack, boiler accessories, boiler fittings, tie
rods, baffles, flow and return turrets and control
panel.
It is recommended that the manufacturer’s trained
engineers should carry out erection and
commissioning, as this will make the LIFETIME
GUARANTEE valid, details on the rear of this
manual.
POTTERTON COMMERCIAL PRODUCTS DIVISION SECTION 2
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 5
NXR4

Installation
Before starting work a risk assessment should be
carried out in the boiler house and its access to
determine and ensure a safe installation and working
environment.
Any person installing or working on the boiler must
be qualified and competent, and in the case of gas
fired boilers attention is drawn to the mandatory
requirement of CORGI. Registration and qualified to
ACOP’s Element 16. They must also be electrically
competent and adhere to the IEE regulations.
Manual Handling – Any person or persons moving or
lifting the boiler or any part of it, should be trained in
manual handling techniques and if necessary use
suitable lifting equipment to reduce the risk of injury
to themselves or other people.
The installation should comply with relevant British
Standard Specifications, Codes of Practice and
current Building Regulations, together with any
special regional requirements of the Local
Authorities, Gas Undertaking and Insurance
Company. All electrical wiring must comply with the
IEE Regulations for the Electrical Equipment of
Buildings.
The installation of the boiler must be in accordance
with the relevant requirements of: -
•Health & Safety at Work Act 1974
•Building Regulations 1991
•Electricity at Work Regulations 1989
•Management of H&S at Work Regulations 1992
•Manual Handling Regulations 1992
•Model Water By-laws 1986
•BS 7671: 1992 – Requirements of Electrical
Installations, IEE Wiring Regulations 16th Edition
•BS 6644: 1991 – Installation of Gas Fired Hot
Water Boilers for Inputs between 60kW and 2MW
•BS 7074: 1989 – Part 2 – Application Selection &
Installation of Expansion Vessels & Ancillary
Equipment for Sealed Water Systems
•BS 6880: 1988 – Codes of Practice for Low
Temperature Hot Water Systems
•BS 779: 1989 – Cast Iron Boilers for Central
Heating & Indirect Hot Water Supply (Rated
Output 44kW and above)
•CP342.2 – Centralised Hot Water Supply
•Gas Safety (Installation & Use) Regulations 1998
•IM/11 Flues for Commercial and Industrial Gas
Fired Boilers and Air Heaters
•IGE/UP/1 – Soundness Testing & Purging
Procedure for Non-domestic Installations
•IGE/UP/2 – Gas Installation Pipework, Boosters
& Compressors for Industrial & Commercial
Premises
Manufacturer’s notes must not be taken in any way
as overriding statutory obligations.
Boiler Siting and Base
The boiler should be sited in accordance with
BS 6644 - 1991. This includes considerations for
protecting the boiler from damage, air for
combustion, clearances for service and access,
temperatures, noise levels, the disposal of boiler
water and the effects of flooding of the boiler house
or seepage from a roof top boilerhouse. See Fig. 2
for required boiler clearances for service and access.
A level non-combustible floor capable of supporting
the weight of the boiler filled with water, see Table 3,
together with any additional weight bearing down on
the base from connections, burner, etc, must be
provided. This should be of an adequate height
above the floor so as to be raised in case of flooding,
but also low enough to allow ease of erection.
Typically a 50mm concrete plinth with an area equal
to that of the plan of the boiler.
For certain special installations a sound proof plinth
may be necessary and a metal plinth resting on anti-
vibration pads is recommended in these instances.
Consideration should also be given to fitting steel
strips beneath the boiler feet for boiler base
protection, see Fig. 3 for base details
The boiler has a water-cooled base and no special
insulation is required. When preparing a site,
reference should be made to Local Authorities and
Building Regulations 1991.
LPG boilers should not be installed in
basements/below ground or in a well.
For further advice on installations, refer to Potterton
Technical Bulletins 1-4
SECTION 2 POTTERTON COMMERCIAL PRODUCTS DIVISION
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 6
NXR4

VENTILATION
Safe, efficient and trouble free operation of
conventionally flued boilers is vitally dependent on the
provision of an adequate supply of fresh air to the
room in which the appliance is installed. Account must
also be taken of any other fuel burning appliance
existing or to be fitted when designing the ventilation
and combustion air systems.
IMPORTANT: The use of an extractor fan in the
same room as the boiler (or in an adjacent room in
communication) can, in certain conditions,
adversely affect the safe operation of the boiler
and therefore must be avoided.
Further guidance on ventilation for gas appliances is
provided by BS 6644 - 1991. For oil see relevant
Standard.
FLUE
To ensure safe and satisfactory operation the chimney
system, which may be individual or common in the
case of modular boiler installations, shall be capable
of the complete evacuation of combustion products at
all times. The effective height of the chimney
terminal(s) above the boiler(s) flue outlet(s) shall
ensure sufficient buoyancy to overcome the
resistance of the bends, tees and runs of the flue pipe
involved and shall terminate in a down draught free
zone. The number of bends used should be kept to a
minimum and runs of flue pipe less than 45° to the
horizontal should be avoided in order to comply with
the recommendations made in BS 6644 - 1991 and
British Gas publication IM/11 “ Flues for Commercial
and Industrial Gas Fired Boilers and Air Heaters”. The
third edition of the 1956 Clean Air Act Memorandum
and Building Regulations should be strictly observed
and approval obtained where applicable, combustion
chamber details are given in Section 1.
IMPORTANT: 90° square bends must not be used
on the flue system, including the boiler flue
spigot, a straight length followed by an “easy
sweep” or lobster back bend should be used.
FLUE SIZE CONSIDERATIONS
Nominal flue connection sizes are given in Table 3,
these sizes refer to the boiler flue connection spigot.
The actual size of the flue system will depend on
individual site applications. Below are general
considerations on sizing flue systems.
Horizontal Flue Runs
Horizontal flue runs are not recommended particularly
over 3m in length, where these are unavoidable
advice should be sought from a flue system specialist.
Common Flue Systems
Where multiple boilers are installed on a common flue
system the flue system should be designed to ensure
the correct operation of the flue on varying load
conditions. For the safe and reliable operation of the
boiler plant it is recommended that the variance in flue
draught available at each appliance under full and part
load operation is designed to a minimum.
(It is essential that the services of a flue specialist
flue system manufacturer are sought for design of
common flue systems).
For further information regarding ventilation and
flueing see Potterton Technical Bulletin No.4, current
issue or see relevant British Standard publication
BS6644 - 1991.
THE ABOVE RECOMMENDATIONS ARE FOR
GENERAL GUIDANCE ONLY. POTTERTON
COMMERCIAL DIVISION CANNOT ACCEPT
RESPONSIBILITY FOR FLUE SYSTEM DESIGNS
BASED ON THE ABOVE RECOMMENDATIONS.
WATER CIRCULATION SYSTEMS
The water circulation system should be indirect and
installed in accordance with the relevant parts of
British Standards Codes of Practice CP342.2 and
BS 6644 - 1991.
The maximum and minimum design temperature
differential across the boiler should be 20°C and 10°C
and the boiler should be prevented from operating
with flow rates giving a temperature difference across
the boiler greater than 25°C based on the full boiler
output.
Boilers operating under constant flow conditions can
be more accurately controlled and are not subject to
excessive temperature stresses.
The boilers MUST NOT be fired under any
circumstances with less than the minimum water flow.
On systems with variable flow rates due to flow
reducing devices, ie. TRVs, zone valves, etc, or where
the minimum heat demand, ie. Summer domestic hot
water load, does not achieve the minimum boiler flow
rate then consideration shall be given to incorporating
a primary loop system.
It is recommended that the system is designed to give
a constant boiler flow rate. For further information on
water circulation systems see Potterton Technical
Bulletin No. 1 current issue.
POTTERTON COMMERCIAL PRODUCTS DIVISION SECTION 3
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 7
NXR4

BOILER PROTECTION
The provision of pump overrun by a time delay relay
or a thermostat situated in the flow pipe close to the
boiler is essential
to remove residual heat from the boiler, see Fig 20,
Section 6.
Unions and isolating valves should be fitted to the flow
and return manifolds so that the boiler can be isolated
from the system if the need arises. Your legal
obligations must be adhered to (i.e. appropriate safety
valves must be fitted).
SYSTEM WATER QUALITY
High efficiency boiler systems require the water
quality of the system water to be controlled by the use
of inhibitors to maintain a neutral Ph and inhibit
corrosion. Additionally the water system should be
free of leaks to prevent raw water make up which will
dilute any inhibitors, promote corrosion and form lime
scale.
Existing Systems
On existing systems where boilers are being replaced
due to failure then the cause should be investigated
before installing new boilers. This can normally be
achieved by cutting open a failed boiler section and
examination for system debris or contamination.
Lime scale is a positive indicator of continuous system
water make up due to water loss. Evidence of
magnetite (black sludge) in the system and the
formation of gas in radiators causing air locking is a
positive indicator of corrosion.
Where an old system shows evidence of
contamination then system cleaning should be carried
out before installation of new boilers. The heating
system should be chemically flushed to remove any
lime scale or corrosion and a corrosion and lime scale
inhibitor added. Lime scale descalers if incorrectly
used could cause any remaining system debris to
continue to breakdown and contaminate the new
boiler causing boiler failure.
Advice on system cleaning and suitable products
should be sought from specialist suppliers of system
cleaners such as Fernox or Sentinel.
It is important to note that corrosion inhibitor can only
be used in an attempt to prevent corrosion from
occurring, where a system has an existing corrosion
problem, inhibitors will be ineffective and the system
requires cleaning.
On existing systems where comprehensive descaling
and desludging cannot be carried out then
consideration should be given to separating the new
boiler system from the existing system pipe work by
the use of plate heat exchangers.
New Systems
New pipe work systems should be thoroughly flushed
with a suitable cleaning agent to remove debris and
flux residues before filling. The system water should
be dosed with a suitable corrosion and lime scale
inhibitor.
System Water Monitoring
The system water should be monitored as part of a
maintenance programme to ensure the following.
Raw water make up is not occurring.
Corrosion and lime scale Inhibitors are still active
Water Ph is below Ph 8.5 other wise on systems with
aluminium content, component failures may occur.
SEALED SYSTEMS
General
Potterton Commercial boilers are suitable for use on
sealed systems designed in accordance with
BS 6644 - 1991 and BS 6880 Part 2. In addition,
reference should be made to the Health & Safety
Executive guidance note PM5 “Automatically
Controlled Steam & Hot Water Boilers”.
SECTION 3 POTTERTON COMMERCIAL PRODUCTS DIVISION
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 8
NXR4

BOILER ERECTION
A lifetime guarantee is available on this boiler when
erection and commissioning is carried out by the
Potterton Commercial service department and the
system meets with our recommendations. Please
refer to our standard terms and conditions for further
details.
Risk Assessment
Before starting work a risk assessment should be
carried out on the boiler house and its access to
determine and ensure a safe installation and working
environment.
Regardless of the type of activity being assessed, the
principles of risk assessments are the same. The
basic steps are: -
•Classify Activity
•Identify Hazards
•Identify Existing Control Measures
•Determine Risk
•Assess Acceptability of Risk
•Prepare a Control Plan
•Implement Plan
•Review Plan
•Record Results
Manual Handling
Any person or persons moving or lifting the boiler or
any part of the boiler, should be trained in manual
handling techniques and if necessary use suitable
lifting equipment to reduce the risk of injury to
themselves and other people.
Personal Protective Equipment
When undertaking any work you must comply with the
Personal Protective Equipment Regulations 1992.
Confined Spaces
A “confined space” as defined in the Health & Safety
Confined Spaces Regulations 1997 means ‘any
place, including any chamber, tank, vat, silo, pit,
trench, pipe, sewer, flue, well or other similar space in
which, by virtue of its enclosed nature, there arises a
reasonably foreseeable specified risk’.
Precautions should be taken in all areas where by
virtue of its even partially enclosed nature, pose a
reasonably foreseeable specified risk.
Electrical Safety
Working on appliances can be broken down into two
main systems of work.
1 Safe systems of work are adapted for all boiler
maintenance and repair work undertaken on site.
2 The work undertaken does not effect the electrical
safety of the appliance. In particular the earth
connected to the buildings fixed electrical
installation
In the case of (1) above, electrical work should only
be undertaken once the boiler has been isolated from
the electricity supply and confirmed electrically dead.
If this is impractical then suitable precautions must be
undertaken to prevent injury.
In the case of (2) above, checks are specified to
identify any abnormality in the electricity supply to the
boiler, as well as to confirm that the boiler electrical
connections are reinstated correctly where it is
necessary to disconnect or reconnect any internal
wiring within the boiler.
If it is necessary to disconnect and reconnect the
appliance from the site electrical installation other than
by means of a plug and socket then additional checks
shall be undertaken by an approved engineer to check
the earth loop impedance with IEE regulations.
Always carry out preliminary electrical safety checks.
All appliances and central heating systems must be
provided with their own means of isolation for safety
purposes especially during installation and
maintenance.
Preparation
Preparatory to installation of the boiler a check must
be made to ensure that suitable facilities are available
for off-loading of the individual waterway sections and
conveying them to the boiler room. Each waterway
section weighs approximately 142 kg and measures
220mm x 860mm x 150mm. Ensure all manual
handling techniques are followed.
Particular attention must be paid to ensuring the
cleanliness of the boiler room and waterway sections,
dust or moisture may result in imperfect adhesion of
the sealants which are applied during the erection of
the waterways. All tapped holes should be degreased
before making connections.
POTTERTON COMMERCIAL PRODUCTS DIVISION SECTION 4
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 9
NXR4

COSHH
During the erection procedure there are a number of
items which are subject to the Control Of Substances
Hazardous to Health (COSHH) Regulations, and may
require specialist personal protective equipment
(PPE) beyond what is normally required. Listed below
are the items subject to the COSHH regulations and
the recommended precautions that should be taken.
For a full breakdown of any of the substances listed
below, please contact the Commercial Technical
Department.
1 Boiler Gasket – No special precautions need to
be taken but the use of normal PPE equipment is
recommended.
2 Ceramic Sealing Braid – Wear gloves, overalls
and safety glasses. In the case of an irritation
rinse the affected area with water and wash
gently. In the case of eye contact, flush
abundantly with water. If irritation persists seek
medical advice.
3 Silicone – Wear gloves, overalls and safety
glasses. In the case of an irritation rinse the
affected area with water and wash gently. If
irritation persists seek medical advice.
4 Mastic - Wear gloves, overalls and safety
glasses. In the case of an irritation rinse the
affected area with water and wash gently. If
irritation persists seek medical advice.
5 Ceramic Fibre Mineral Wool - Wear gloves,
overalls and safety glasses. In the case of an
irritation rinse the affected area with water and
wash gently. In the case of eye contact, flush
abundantly with water. If irritation persists seek
medical advice.
Potterton Commercial Customer
Erection/Assembly Check List
The items listed below have been put together as a
guide to the actions that should be completed before
the erection/assembly of a boiler takes place.
1 Site access available for persons carrying out the
proposed work.
2 Site managers/personnel aware that work will be
taking place.
3 Risk assessments carried out on possible risks
that may effect the persons carrying out the
proposed work.
4 Sections and fittings boxes should be positioned
adjacent to the plinth(s) within the boiler house
prior to persons carrying out the proposed work
attending site. If this is unable to be done notice
prior to attending site be given.
5 When boilers are to be stripped and rebuilt, labour
and transport should be provided for moving the
sections from the delivery point to the final
erection point. If this is unable to be provided
notice prior to attending site should be given.
6 Sections/casing, etc, should be kept in a clean dry
area prior to erection/assembly.
7 Water should be available.
8 A drain off area should be available.
9 Power should be available
10 A site representative should be available at all
times.
11 Clear instructions supplied to the persons carrying
out the proposed work regarding positioning the
boiler.
12 Fire evacuation procedures, facilities availability,
specific health and safety information, etc, should
be provided.
Items 7 to 10 are essential if boilers require pressure
testing.
SECTION 4 POTTERTON COMMERCIAL PRODUCTS DIVISION
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 10
NXR4

BOILER ERECTION
SECTION ASSEMBLY
The boiler sections are not self-supporting until the
boiler block is fully assembled. The sections are
connected using a nipple system. To ensure a sound
water tight fit nipple sealing paste is provided for
assembling the sections.
IMPORTANT: Ensure the boiler is adequately
supported especially when pulling up sections.
The Manual Handling Regulations should be
followed.
Erect the Boilers as follows: -
1 Open the boiler fittings box.
2 Clean the nipples using a solvent cleaner (not
supplied), ensuring all guidelines are followed.
3 Clean both the top and bottom nipple ports of all
sections with a solvent cleaner and ensure that
they are rust free, dirt-free and burr free, if
necessary clean with emery cloth.
4 Stand the rear section up and ensure that it is
supported securely. Ensure correct manual
handling techniques are used.
5 On the rear section clean the groove with a metal
brush prior to application of the heat-resisting
compound. Paste the machined edges and
external groove (see Fig. 5)
CAUTION: To ensure leak free assembly never use
old nipples and only use the special compounds
supplied with the boiler.
6 Using a clean brush coat the nipples and nipple
ports with the compound supplied.
7 Insert the nipples into the nipple ports by hand
and using a piece of wood and a hammer/mallet
gently drive the nipples into place. Do not drive
them in too far as tightening should be achieved
when bringing the sections together.
Ensure that the nipples fit square and check depth
of penetration by using the template supplied (see
Fig. 5).
Ensure that the nipples are correctly aligned
as an out of line nipple can cause the section
to crack when it is pulled up.
8 Clean the nipple ports on the rear intermediate
section and apply the sealing compound. Position
the intermediate next to the rear section with the
letters AR facing forwards.
9 Slide the sections together so that the
intermediate section nipple ports slightly engage
with the corresponding nipples on the rear
section. Ensure all manual handling techniques
are adhered too.
10 Using a piece of wood and a hammer/mallet hit
the top and bottom nipple ports on the
intermediate section alternately so as to achieve
temporary assembly. Ensure that they fit perfectly
and squarely and then proceed with tightening as
described under “Tightening the Sections”.
Ensure that the intermediate section is aligned
parallel to the rear section.
11 Apply the heat-resisting compound to the nipple
ports ready to receive the next section.
POTTERTON COMMERCIAL PRODUCTS DIVISION SECTION 4
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 11
NXR4

Fig. 4 – Fluegas Passes
Fig. 5 – Section Build
Front Intermediate Section
Centre Intermediate Section
Rear Intermediate Section
AR AVM
REAR REAR
INTER
MIDDLE
INTER
FRONT
INTER
FRONT
Apply Jointmastic Silicone to
the surfaces in bold
AR AVM
or or
SECTION 4 POTTERTON COMMERCIAL PRODUCTS DIVISION
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 12
NXR4

Fig. 6 – Section Layout
Markings Face
Towards Front Front Section Middle Inter Section M
Front Inter
Section AV
Rear Inter
Section AR
Rear Section
409
412
411
410
417
413
414
416
415
No of Sections
SIZE Front Front
Inter Middle Rear
Inter Rear
409 1 2 3 2 1
410 1 2 4 2 1
411 1 3 4 2 1
412 1 3 5 2 1
413 1 3 5 3 1
414 1 4 5 3 1
415 1 4 6 3 1
416 1 5 6 3 1
417 1 5 6 4 1
POTTERTON COMMERCIAL PRODUCTS DIVISION SECTION 4
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 13
NXR4

PULLING UP THE SECTIONS
In order to erect the boiler it is necessary to use a set
of assembly tools, please find options available:
1 Use our Potterton Commercial Service
Department to erect the boiler.
2 Purchase of assembly tools from ourselves.
3 Supply your own assembly tools.
Note: Sections should be pulled together one at a
time.
In each case the following method of assembly is
recommended.
1 Assemble the top and bottom pulling up bars
through the top and bottom nipple ports and pull
up the sections until metal to metal contact is
made. This will cause the compound between the
sections to squeeze out.
The sections should be pulled up evenly applying
equal pressure to top and bottom pulling up bars.
Section alignment should be checked throughout
the process.
To ease assembly tap around the periphery of the
sections with a mallet.
NEVER HIT THE MACHINED SURFACES.
2 Proceed for the other sections one by one as
before.
CAUTION: It is imperative that the intermediate
section assembly order is adhered to (see Fig. 6).
The markings AR, M and AV (see Fig. 5) must
always be pointing towards the front and all
arrows must face the same way.
After having assembled three or four sections fit the
rear Stainless Steel Furnace Protective Plate in
position against the rear section (see Fig. 10).
Complete the assembly with the front section
proceeding as before.
3 Keep the assembly tight and seal the joints
externally as follows:-
i) Clean the “V” groove between each pair of
sections and allow to dry.
ii) Apply the silicone seal with the gun provided
(see Fig. 7).
iii) Smooth the bead with a damp tool (eg. A
spatula).
Fig. 7 – Sealing
4 Fit the tie rods and tighten as follows:-
Fit the special spring washers (see Fig. 8) at the
rear ends of the rods. Tighten the nuts leaving a
1mm gap between each turn of the spring washer.
This operation should be carried out one rod at a
time.
Fig. 8 – Tie Rod Fixing
5 Loosen the assembly bars and remove
6 Continue with assembly of the boiler.
EXCHANGER ASSEMBLY
Open the “Accessories for Exchanger” package.
Flow Distributor
Insert eight M16 x 65 studs around the rear section
flow and return orifices. If necessary on sizes 412 to
417 insert the flow distributor with its gasket (see Fig.
10) into the return orifice.
Boiler Set Up
Set the exchanger in its final position and ensure it is
level. Ensure that each section is in contact with the
base, if not use metal shims.
Assembly Tools
Silicone Seal
1mm
SECTION 4 POTTERTON COMMERCIAL PRODUCTS DIVISION
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 14
NXR4

Top Flange
Fit the four M16 x 66 studs on the upper part of the
front section. Fit the top flange inserting its gasket and
using four nuts and six washers.
Sensor Pocket
Screw the two sensor pockets into both of the
threaded holes in the top flange.
Sludge Flushing Bottom Flange
Fit four M16 x 66 studs on the lower part of the front
section. A 2” threaded hole is provided on this flange
to enable a flushing valve to be fitted. This is not a
United Kingdom requirement so the 2” blanking plug
provided should be fitted.
Outlet Manifold
Fit the outlet manifold onto the four upper studs on the
rear section with the ½” orifice on the top not
forgetting to insert the gasket (see Fig. 10). Fit the ½”
sensor pocket into this orifice.
Inlet Manifold
Fit the inlet manifold onto the four lower studs on the
rear section with the ½” tapping on the top not
forgetting to insert the gasket. Fit the ½” sensor
pocket into this tapping. Fit the 1” – ¾” reducing bush
into the side tapping and fit the ¾” drain cock into the
bush.
Fig. 9 – Burner Door
Slip on the Welded Flange
Connect the PN16 – DN 125 flanges onto the
pipework then fasten them to the manifolds inserting
the seals (eight HM16 x 75 bolts, eight nuts, and eight
washers for each flange).
Hydraulic Test
After checking the connections proceed slowly with
filling the system ensuring that all air is purged. After
filling carry out the hydraulic test (1.5 x working
pressure).
Flue Hood (see Fig. 10)
Screw the shortest thread section of the four M8 x 40
studs into the upper part of the rear section. Fit and
bond the ceramic cord. Fit the fluehood onto the studs
and fasten with four HM nuts and four washers.
Tighten the nuts.
Flue Connection
Connect by the most direct route possible without
reducing the flue size into the stack. Check for correct
connection.
Flue Access Doors
Screw the eighteen M8 x 45 studs into their positions
in the front section (see Fig. 10). Position the pre-
assembled flue access covers (see Fig. 10). Fasten
into position with the wing nuts provided. On the door
hinge side the access door wing nuts must be
replaced with a standard HM8 nut in order to allow the
door to open.
POTTERTON COMMERCIAL PRODUCTS DIVISION SECTION 4
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 15
NXR4
31
13
30
30
13
30

Fig. 10 – Exchanger (Exploded View)
2” Plug
Stainless Steel
Furnace Protective
Plate
Nipple
Burner Support Door
(see Fig. 9)
Front Section
Bottom Front Flange
Flame Viewing
Port
Section
Markings
Marking to be
Towards Front
Flue Access DoorsTop Flange
Sensor Pockets
Tie Rods
Top Outlet Manifold
Flue Spigot
Rear Section
Rear Flue Hood
Slip-On Weld Flange
Flow Distributor
409 – 411 – Not Fitted
412 – 416 – 630mm
417 – 1000mm in two pieces
Drain Cock
Bottom Inlet Manifold
SECTION 4 POTTERTON COMMERCIAL PRODUCTS DIVISION
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 16
NXR4

Burner Support Plate (see Fig. 9)
Bond the ceramic fibre cord in the front section groove
(the cord should be joined on the opposite side to the
hinges).
Mount the complete sight glass (item 3) onto the door
(item 4) with the studs (item 5), washers (item 2) and
wing nuts (item 1) provided.
Place the circlip (item 19) onto the hinge pin (item 21).
Slip the male (item 18) and female (item 17) hinge
pieces and washers (items 20) onto the hinge pin.
Fit the complete assembly to the boiler using the
screws (item 15) and washers (item 10).
Fit the fastening plates (item 11) onto the boiler with
the screws (item 9) and washers (item 10). Screw the
studs (item 12) into the fastening plates.
Screw the centring nuts (item 6) onto the male hinge
piece (item 18). Fit the door onto the hinge (item 18)
and screw the other two centring nuts (item 6) onto
the hinge (item 18).
Burner Door (see Fig. 9)
Set the four stainless steel lugs (30 and 31) using the
“Rapid” fastening system on Ø8 rods.
Place the mineral wool insulation (brown) against the
door then the ceramic fibre (white) on the combustion
chamber side (see Fig. 9).
Fold the four stainless steel lugs over the ceramic
fibre.
Cut the insulation material using the burner draught
tube as a template. This can be easily cut using a
sharp knife or hacksaw blade.
Close the door and fasten using nuts (item 7) and
washers (item 8). Adjust the door to ensure a leaktight
seal by adjusting nuts (Items 6 & 7).
IMPORTANT: After a few hours operation, check
the door tightness. Adjust if necessary using the
four adjusting nuts (item 6) on the hinge side and
the two locknuts (item 7) on the opening side.
Fig. 11 – Insulation Blanket Position
Fig. 12 – Number & Width of Side Panels
Boiler
Size
409
410
411
412
413
414
415
416
417
Number & Width of Side Panels
325 980
560 560
325
325
325
325
325
325
325
325
840
840840
840980
980
980
700700700
560
700
700700
700
POTTERTON COMMERCIAL PRODUCTS DIVISION SECTION 4
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 17
NXR4

Fig. 13 – Casing (Exploded View)
40 Front Right / Rear Left Upright
41 Front Left / Rear Right Upright
42 Cross Member
43 Common ½ Cross Member
43A Splice Plate
44 ½ Cross Member
45 Front Top Panel
46 Top Panel
47 Front Right Side Panel
48 Front Left Side Panel
49 Side Fastening Bracket
50 Side Fastening Lug
51 Side Panel
52 Upper Rear Metal Plate
53 Lower Rear Panel
54 Rear Side Panel
55 Lower Front Panel
56 Right Front Panel
57 Left Front Panel
58 Upper Front Panel
59 Bag of Casing Screws
SECTION 4 POTTERTON COMMERCIAL PRODUCTS DIVISION
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 18
NXR4
44 51 43 46 54 52 54
41 44
43A
42
48
57
45
42
43
58
40
55 56 49 47 50 51
53
51

FITTING THE CASING
Open both casing packages.
Exchanger Lagging Materials (see Fig. 11)
Cover the whole exchanger with the lagging blanket
(50mm thick) which is supplied in several 3.2m long
strips.
Assemble the strips using pins.
Wedge the ends of the lagging blanket between the
exchanger and tie rods.
Vertical Uprights (40 & 41)
Place the vertical uprights on the boiler front (two
screws HM8 x 16 with washers).
Do the same at the back of the boiler.
Left & Right Hand Cross Member (42, 43, 43a & 44).
For boiler sizes 412 to 417 the cross member is
supplied in two pieces with a splice plate (43a).
Assemble these two half cross members (43 & 44)
using the splice plate to join them.
Mount the cross members with a larger stud vertical
on the uprights. Secure with one M8 x 16 screw in the
front square hole and one M8 x 16 screw with washer
in the rear oblong hole.
Align the front ends of the cross members with the
vertical uprights on the front of the boiler.
Securely fasten the uprights and the cross members.
Front Top Panel (45)
Place the front top panel on the cross members with
the locking pegs pointing to the back. Centring is
carried out using the locking peg found underneath
the top front panel which locates in the square hole in
the top of the cross member. Secure using two M5
screws in the oblong holes.
Top Panels
Assemble as per Fig. 12 working from the front top
panel locating the locking pegs in the square holes.
Put two M5 screws in the oblong holes but do not
tighten.
Right & Left Front Panels (47 & 48)
Hook the side front panel onto the top front panel
using the two locking pegs. The side panel locking
pegs are located on the front.
Side Fastening Bracket (49)
Insert the side panel fastening bracket pin into the
lower fold of the side panel. Secure to the upright with
one M5 x 10 screw.
Fastening Pin (50)
Clip the bottom bracket onto the boiler tie rod. Insert
the pin into the side panel. Slide the pin along the tie
rod to line up with the panel.
Side Panels (51)
Place the side panels on the fastening holes of the
intermediate top panels (see Fig. 12). Rotate the
panel to clip it in the pin of the bottom bracket.
Continue in this way with the rest of the side panels
finishing with two fastening pins.
Adjustment
To carry out complete casing adjustment start on the
right, pull the top panel forwards and secure the
fastening pin screw at the bottom. Do the same on the
left front and then the rear.
Lower Back Panel (53)
Locate the panel around the manifold and slide it into
the notches.
Upper Back Metal Plate (52)
Secure in place using two M5 x 10 screws.
Right & Left Rear Side Panels (54)
Hook the left and right side panels onto the fastening
lugs.
Lower Front Panel (55)
There is a pre-cut recess in this panel to
accommodate the flushing valve if fitted. The lagging
blanket may need to be cut. Hook onto the side panel
pegs.
Left & Right Front Panels (56 & 57)
Position these panels on the left and right of the
burner door opening using the locking pegs.
Control Panels
Assemble the panel as shown on in Fig. 14 & 15.
Upper Front Panel (58)
Locate this panel on the pins fitted in items 56 and 57.
The panel is held in position with magnetic catches.
POTTERTON COMMERCIAL PRODUCTS DIVISION SECTION 4
INSTALLATION, OPERATION & MAINTENANCE MANUAL
PAGE 19
NXR4