GUH RANGE PROPANE GAS FIRED UNIT HEATERS
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BENSON GUHA/GUHC
RANGE
(PROPANE GAS FIRED UNIT HEATER)
I N S T A L L A T I O N C O M M I S S I O N I N G
S E R V I C I N G
U S E R I N S T R U C T I O N S
October 2002
(Issue 3)
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
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~ C O N T E N T S ~
S E C T I O N A
1.0 Compliance Notices
1.1 Certificates of Conformity
1.2 General Product Information
1.3 General Requirements
1.4 Delivery & Pre-installation Checks
1.5 Warranty
2.0 Installation
2.1 Installation Clearances and Mounting Heights
2.2 Heater Mounting
2.3 Warm Air Circulation
2.4 Air Supply
2.5 Flue Installation
2.6 Electrical Installation
2.7 Electrical Panel
2.8 Time Switch
2.9 Room Thermostat
2.10 Fan and Limit Controls
2.11 Summer / Ventilation Switch
2.12 Gas Installation
3.0 Commissioning
3.1 Electrical Pre-Tests
3.2 Gas Supply Pre-Tests
3.3 Ignition Sequence Manual Versions
3.4 Ignition Sequence Automatic Versions
3.5 Hand Over
4.0 Servicing
4.1 Servicing Procedure
5.0 Fault Diagnosis by Flow Charts
6.0 Wiring Diagrams
7.0 Technical Data Formulae
7.1 Technical Data Common Information
7.2 Technical Data Heater Information
8.0 Reference Information
9.0 Parts Listing
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
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S E C T I O N B
Warranty Registration
Updated Information
Timer Information Manual
S E C T I O N C
10.0 Introduction
10.1 Commissioning / Hand over
10.2 Servicing
10.3 Start up Procedure
10.4 Start up Procedure Automatic Versions
10.5 Stop Procedure Manual / Automatic Versions
10.6 Shut Down Procedure
10.7 Fail-safe Situations
10.8 Contact Information
I L L U S T R A T I O N S
Fig 1 Exploded view
Fig 2 - 12 Flue Systems
0Fig 13 - 14 Gas Train & Pilot Installation
Fig 15 - 16 Electrical Installation
Fig 17 - 18 Axial & Centrifugal Fans
Fig 19 - 27 Fault Diagnosis Flow Charts
Fig 28 - 35 Electrical Drawings
Fig 36 Main Dimensions
Any reference made to Laws, Standards, Directives , Codes of Practice or other recommendations
governing the application and installation of heating appliances and which may be referred to in
Brochures, Specifications, Quotations, and Installation, Operation and Maintenance manuals is done so
for information and guidance purposes only and should only be considered valid at the time of the
publication. Benson Heating cannot be held responsible from any matters arising from the revision to or
introduction of new Laws, Standards, Directives, Codes of Practice or other recommendations.
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
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1.0 Compliance notices
The Benson GUH range of warm air heaters detailed herewith are manufactured by Benson Heating
within a strictly controlled environment within the parameters of ISO9001
The Benson GUH Range has been independently tested and assessed, and has been found to meet the
Essential Requirements of the following European Directives.
Gas Appliance Directive (90 / 396 / EEC)
Machinery Directive (89 / 392 EEC)
Low Voltage Directive(73 / 23 / EEC & 93 / 68 / EEC)
Electromagnetic Compatibility Directive (98 / 336 / EEC & 91 / 31 / EEC)
Product Liability Directive 65 / 374 / EEC)
The manufacturer has taken reasonable and practical steps to ensure that Benson GUH Range of Heaters
are safe and without risk when properly used. These heaters should therefore only be used in the manner
and purpose for which they were intended, and in accordance with the recommendations detailed
herewith.
The heaters have been designed, manufactured, assembled, inspected, and tested, with safety and quality
in mind, there are certain basic precautions which the installer and user should be aware of, and they are
strongly advised to read the appropriate sections of the information pack accompanying the heater, prior
to installation or use.
Benson Heating supports all new products being supplied to their customers with a comprehensive
information pack; this clearly defines mandatory instructions for the safe installation, use, and
maintenance, of the appliance(s).
Where proprietary items are incorporated into Benson Heating products, detailed information and
instructions are also provided as part of the information pack.
It is the responsibility of the installer, owner, user, or hirer, of such products supplied by Benson Heating,
to ensure that they are familiar with the appropriate information/manuals, supplied by the manufacturer,
and that they are suitably aware of the purpose of the manuals and the safety instructions. In addition,
operators must be suitably trained in the use of the appliance so as to ensure its continued safe and
efficient use.
Benson Heating has a commitment to continuous improvement, and therefore reserves the right to amend
or change the specification of the GUH Heater range subject to agreement from The Notified Body.
Contained within the text of the manual, the words 'Caution' and 'Warning' are used to highlight certain
points.
Caution is used when failure to follow or implement the instruction(s) can lead to premature failure or
damage to the heater or its component parts.
Warning is used when failure to heed or implement the instruction(s) can lead to not only component
damage, but also to a hazardous situation being created where there is a risk of personal injury.
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
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The Benson GUH range of heaters conform to the following European Harmonised Standards.
BS EN 621 1998 Requirements for non domestic gas fired forced convection air heaters for space heating
without a fan to assist transportation of combustion air and/or combustion products.
BS EN 292 - Part 1 : 1991
Safety of Machinery - Basic Concepts, General Principles for Design
Basic terminology, methodology
BS EN 292 - Part 2 : 1991
Safety of Machinery - Basic Concepts, General Principles for Design
Technical Principles and Specifications
BS EN 60204 - Part 1 : 1993
Safety of Machinery - Electrical Equipment for Machines
Specification for General Requirements
BS EN 60335 - Part 1 : 1988
Safety of Household and Similar Electrical Appliances
General Requirements
BS EN 55014 - 1993
Limits and methods of measurement of radio disturbance characteristics of electrical motoroperated and thermal appliances for household and similar purposes, electrical tools and
similar electric apparatus
BS EN 50165 - 1995
Electrical Equipment of non-electric heating appliances for household and similar purposes,
safety requirements
1.1 Certificates of conformity
Declarations and Certificates are available upon request from the Quality Control Department at Benson
Heating .
Notified Body PIN Reference is 63AQ0533
1.2 General product information
The Benson GUH Range have an output rated at between 29.3kW to 73.3kW, and 117.3kW are available
with either axial or centrifugal fans
The Model Range is made up as follows;
Each heater must be connected to its own individual open flue in accordance with the manufactures
recommendations.
MODEL 100 125 165 205 250 400
OUTPUT 29.3 37.0 48.4 61.6 73.3 117.3
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
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Cabinet
Manufactured from zintec coated steel, finished in a durable stove enameled polyester powder
paint.
Heat Exchanger
Manufactured from aluzinc coated steel, and formed from pressed and welded sections into a
multiple clam assembly.
Flue Outlet
Fabricated from aluzinc coated steel . The part is designed to terminate with a spigot . the
assembly incorporates the down draught diverter.
Burner
The atmospheric gas burner is manufactured from aluzinc coated steel and is located beneath the
clam. The complete burner rack is easily withdrawn through the front of the heater.
Standard heaters are supplied suitable for Propane Gas.
Burner Control
Models 100 – 250 & 400 heaters are fitted with a manually operated piezo spark igniter and low
consumption pilot, linked via an integral thermocouple to the main multifunctional valve.
An automatic facility is also available for all models within the range.
Fan
Models GUH (A) are supplied with an Axial fan for free blowing applications .
Models GUH (C) are supplied with Centrifugal fans suitable for ducted applications
Note
Neither asbestos nor soft soldered joints are used in the construction or manufacture of the Benson range
of GUH Heaters. The materials selected for use can withstand the mechanical, chemical, and thermal
stresses which they will be subject to during foreseen normal use when installed in accordance with the
manufacturers recommendations.
1.3 General requirements
Caution
Ensure that the gas service to the appliance carries the correct gas type and that the supply pressure is in
accordance with the supply type and pressure stated on the appliance data plate.
Installation, commissioning, and servicing must only be carried out by appropriately qualified and
competent persons.
Warning
Unauthorised modifications to the appliance, or departure from the manufacturers guidance on intended
use, or, installation contrary to the manufacturers recommendations may constitute a hazard.
Note
To ignore the warning and caution notices, and to ignore the advice from the manufacturer on
installation, commissioning, servicing, or use, will jeopardise any applicable warranty, moreover, such a
situation could also compromise the safe and efficient running of the appliance itself, and thereby
constitute a hazard.
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The installation of the appliance must meet all the relevant European, National, and local criteria.
(See sections 2 and 8).
Prior to installation the following points should be considered;
a) The position of the heater for the optimum efficient distribution and circulation of warm air
b) The position of the heater relative to the route of the flue
c) The position of the heater relative to the supply of gas
d) The position of the heater relative to the electrical services, wiring routes, and if appropriate, any
additional controls.
e) The position of the heater relative to the supply of fresh air
f) The position of the heater relative to potential stratification / circulation problems, which generally
occur at higher levels and which may be overcome through the provision of a suitable de-stratification
unit.
g) The position of the heater relative to service and maintenance requirements
Caution
The heater must not be installed within an area where the conditions are unsuitable, e.g. where the
atmosphere is highly corrosive, has a high degree of salinity, or where high wind velocities may affect
burner operation. Suitable protection should be provided for the appliance when it is located in a position
where it may be susceptible to external mechanical damage from; for example, fork lift trucks, overhead
cranes etc.
1.4 Delivery and pre-installation checks
The heater is supplied wrapped in heavy duty protective polythene, mounted on a pallet.
On receipt of the heater, the following checks should be carried out;
a) The model is as per order
b) That it is undamaged
c) That it is suitable for the gas supply and pressure
d) That it is suitable for the electrical supply
If any of these points are not satisfied then contact should be made with the Sales Office at Benson
Heating as soon as possible by telephoning 01547-528534. In the case of claims for damage, this must be
reported in writing within 24 hours of delivery, in order to comply with insurance criteria
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1.5 Warranty
The heater is supplied with a 1 year warranty on all parts except the thermocouple.
In addition to this there is also a 5 year time related warranty on the combustion chamber.
The warranty commences from the date of dispatch from the manufacturer, and is subject to the terms
detailed within the Benson Heating 'conditions of business'.
Note (i)
The warranty may be invalidated if -
a) The warranty registration/commissioning card has not been completed and returned to Benson Heating
b) The installation is not in accordance with the general requirements of this manual
c) The flue arrangement and air supply for the heater are not in accordance with the manufacturers
recommendations, codes of practice, or similar standards
d) Air flow through the heater is not in accordance with the manufacturers technical specifications
e) Internal wiring on the heater has been tampered with or unauthorised service/repairs undertaken
f) The main electrical supply input to the heater has been interrupted during the heating mode
g) The heater has been subject to and affected by the ingress of water in any form
h) The heater is not operated at the rating(s) laid down in the manufacturers technical specifications
i) The heater has not been operated or used within the normal scope of its intended application
j) The manufacturer's recommended minimum service requirements have not been complied with
Note (ii)
All warranty claims must contain the following information to enable processing to take place;
(1) Heater model
(2) Heater serial number
(3) Order reference/date of order, together with full installation details (name and address)
(4) Details or symptoms of fault
(5) Installers name and address.
Faulty parts must be returned to the Benson Heating Spares Department, the address of which is provided
on the cover of this manual. Any such parts will undergo inspection to verify the claim. Replacement
parts supplied prior to this may be charged, and a credit supplied upon subsequent validation of the
warranty claim.
Consumable items are specifically not included within the scope of the warranty.
Note (iii)
Notification is required immediately a fault is suspected.
The manufacturer will not accept responsibility for any additional damage that has been caused, expense
incurred, or consequential loss resulting from any failure of the heater(s).
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2.0 Installation
Note
It is a requirement that only qualified and competent personnel may undertake installation
commissioning and servicing of GUH Range Heaters.
Warning
All of the basic criteria must be satisfied prior to commencing installation and commissioning,
additionally, the Unit Heater must be positioned and installed so as to comply with all the relevant
standards and guide lines (see section 8.0), as well as meeting national and local fire regulations and
insurance criteria, especially if it is proposed that the heater is to be installed within a special risk area
(e.g. proximity to where petrol engined vehicles are stored or parked, where cellulose spraying takes
place, where woodworking machinery is operated, etc,).
Indirect fired heaters must not be located in hazardous areas, however, it is permissible for the heater to
supply air to such areas. The heater must not be installed within an environment where there is a high
concentration of chlorides, fluorides, salts, or other aggressive or volatile chemicals/compounds.
Nor should the heater be positioned where the burner could be adversely affected by high winds or
draughts.
The heater must be installed so that it is level. Supports for the heater must be sufficiently robust to
withstand the weight of the heater and any ancillary equipment. Any combustible material adjacent to the
heater or flue system must be so placed or shielded so that its surface temperature does not exceed 65C
The location chosen for the heater must allow for the fitting of an effective flue system.
The location must also allow for adequate clearance for the air supply, return air circulation, oil supply,
electrical supply, whilst also providing good and safe working access.
The heater must be installed so that it is level, supports for the heater must be sufficiently robust to
withstand the weight of the heater and any ancillary equipment
Any combustible material adjacent to the heater or flue system must be so placed or shielded so that its
surface temperature does not exceed 65oC. Generally a free blowing heater should be located at a height
(measured from floor level to the base of unit) as detailed within section 2.1
The location chosen for the air heater must allow for the fitting of an effective flue system. It must also
allow adequate clearance for the air supply, return air circulation, gas supply, electrical supply and also
provide good service access.
Suspended free blowing Unit Heaters are at their most effective when located as close to the working
area as possible. However care should be exercised to avoid directing the discharged air directly onto the
occupants of the area to be heated.
Where the passage of cold air causes problems (eg by entrances, loading bays etc) it is considered
favourable if the heater is positioned so as the discharge towards or across the cold air source from a
distance from 1.5m - 6m dependent upon the size of the entrance and the air throw characteristics of the
heater. On exposed walls heaters should be positioned so as to discharge towards, or along the length of
the exposed wall.
In areas where it is proposed that more than one heater is to be installed, a general scheme of circulation
should be drawn up and maintained, thereby offering the best heat distribution. Air pressure within the
area heated and the outside air pressure must remain the same, factors influencing this would be the
presence of extraction systems, ventilation systems, and various types of process plant.
GUH (A) Heaters are only suitable for free blowing applications or where the duct length does not
exceed 2 metres.
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In which case the cross- section of the duct must be at least the same as that of the heater discharge grille
Where the heater is positioned to discharge through a wall opening a clearance of 2 metres in front of the
unit is required to allow for the correct operation of the down draught diverter and access for servicing.
In such applications a stub duct should be fitted and sealed at the interface between the discharge grille
on the heater and the opening in the wall.
2.1 Installation Clearances and Mounting Heights
The Heater must be installed so as to provide the following clearances
FRONT REAR TOP LEFT RIGHT BASE
2000mm 500mm 200mm 500mm 500mm 250mm
The recommended maximum and minimum mounting heights in metres are as follows:
MODEL 100 125 165 205 250 400
Max 3.03 3.33 3.64 3.94 3.94 4.24
Min 2.12 2.42 2.73 2.73 2.73 2.73
Any combustible material adjacent to the air heater and / or flue system must be so placed or shielded so
as to ensure that its temperature does not exceed 65Deg C
2.2 Heater Mounting
The heater and flue must be adequately supported by one of the following methods ;
a) Suspension by steel drop rods or straps from the M12 fixing points located on top of the heater
These must be of sufficient strength to safely carry the weight of the unit and ancillary equipment. The
straps may only drop vertically to eyebolts, if used; I.E. They must not be joined to the eyebolt at an
angle to the vertical, and eyebolts if used should be of an approved type.
b) On specifically designed cantilever brackets mounted from a non-combustible wall.
c) On a level non-combustible surface capable of adequately supporting the weight of the unit and
ancillary equipment . Under these circumstances approved mounting feet must be fitted.
Note
GUH (C) Models cannot be supported on cantilever brackets.
2.3 Warm Air Circulation
The air heater should be positioned to enable maximum circulation of discharged warm air within the
area to be heated, whilst taking account of personnel within the area, sources of cold air ingress , and
obstructions.
The air temperature rise on passing the heat exchanger is typically around 34Deg C
A full and unobstructed return air path to the air heater must be provided (see 2.4 Air Supply).
Where the heater is positioned to deliver blown air through an opening in a wall, return air intakes should
be located so that they cannot become blocked. Similarly these intakes must be positioned so as not to
draw in odours, fumes, hazardous vapours or particles.
Barrier rails should be provided to eliminate the risk of combustible materials being placed within 1M of
the warm air outlet.
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2.4 Air Supply
Provision must be made for the existence of an air supply in order to satisfy both combustion and
ventilation criteria.
It is a requirement that the area where the air heater is located must have a permanent air vent of
negligible resistance direct to the outside air.
Such air vents must be positioned so as not to become blocked or flooded, nor should they be placed so
as to introduce undesirable matter (e.g. flammable, volatile, or aggressive chemicals/compounds or
potentially hazardous or harmful substances) either direct from the outside, or through their proximity to
an adjacent extraction system.
The criteria necessary for establishing the minimum size of natural vents is detailed as follows;
Position of vent Area of vent direct to outside
Low level (<60kW) 9.0cm
2
per kW
Low level (>60kW) 540cm2 + 4,5cm2 per kW of
(Inlet) rated input per heater
High level (<60kW) 4.5cm
2
per kW
High level (>60kW) 270cm
2
+ 2,25cm2 per kW of
(Outlet) rated input per heater
Where mechanical ventilation is used it is a requirement that the inlet is of the mechanical type, and the
outlet is either mechanical or natural.
Caution
Systems of ventilation that employ mechanical extraction and natural inlet must not be used.
Furthermore, where the air supply is by way of a mechanical means the inlet must be positioned at low
level and be capable of providing a minimum throughput as detailed in section 7.2 of this manual.
The natural extraction air vents must have a minimum area as per the above table, and it is strongly
recommended that natural extraction vents are situated at high level.
Additionally, an automatic control interlocked to the burner must be fitted to ensure burner shutdown in
the event of airflow failure or restriction.
When the area to be heated already has an extraction system, the size of the air vent must be sized to
account for this and to maintain the required number of air changes
If the heater is to be installed within its own separate building or plant room, the above details do still
apply, as does the requirement for minimum space, further consideration should be made for free air for
recirculation to avoid the possibility of negative pressure in the plant room (see guidance notes below)
Additionally the maximum temperature within the plant room should not exceed 32DegC
Note
It is strongly recommended that BS 6230 : 1991 is referred to for further information concerning
ventilation requirements.
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2.5 Flue Installation.
An integral flue spigot is fitted to all GUH Air Heaters thereby allowing the flue to connect directly to
the heater.
The design of the flue must ensure that it can be disconnected to allow for cleaning and servicing.
Further more all of the flue section joints must face upwards and the seal between the sections achieved
through the use of approved caulking string and / or grout.
Warning
It is essential that the products of combustion are flued to the outside of the building.
Each heater must have its own separate flue, with a flue diameter of not less than is detailed in section 7.2
within this manual.
The flue assembly must comply with all the relevant regulations regarding height and materials, and must
terminate with an approved flue terminal.
All GUH Air Heaters are equipped with a built in down draught diverter which prevents the recirculation
of combustion products, consequently an external draught diverter, barometric damper, or anti spillage
system must not be installed. Such devices are unnecessary on the GUH range of heaters.
Alterations to the built in down draught diverter must not be carried out, and it is necessary to provide a
minimum unobstructed clearance in front of the heater of 2Metres to ensure that the down draught
diverter will function correctly and also provide access for servicing.
In order to provide adequate natural draught, the minimum vertical length of flue must not be less than
2Metres.
The flue should rise vertically, and the number of bends should be kept to a minimum.
The temperature of the combustion products can be as high as 260° C and therefore tend to rise naturally
within the flue. Unnecessary bends and restrictions should therefore be avoided.
Provision for the disconnection of the flue for servicing and inspection purposes must also be made, and
where appropriate bends should be fitted with access covers, again to allow for cleaning and inspection.
The position of the flue and its terminal should be such that it does not impair the combustion process. It
should terminate in an exposed position so as to allow the free escape of flue gases without risk of their
re-entering the building through windows, ventilation ports etc.
The following illustrations of different flue configurations are included for guidance purposes (see
figures 2-12 )
If the flue does not have access to an existing chimney then it should be extended through the roof or
wall to a height of at least 1M above that of any object within 3.5M of the terminal.
The materials from which the flue is constructed must be non-combustible, resistant to internal and
external corrosion, and be capable of withstanding the stresses and loadings associated with normal use.
When designing the flue system the prevention of the formation and entrapment of condensation must be
a key consideration.
Twin wall or insulated systems are recommended, as they tend to inhibit the formation of condensates.
Where condensation is unavoidable traps should be included to encourage the condensates to flow freely
to a point from which they may be released, preferably into a gully.
The condensate pipe from the flue to the disposal point must be made from corrosion resistant pipe of not
less than 25mm internal diameter.
If the flue passes through a wall, ceiling, or roof made from combustible material then it has to be sleeved
so as to provide a minimum of a 25mm void between the exterior of the flue and the internal wall of the
sleeve.
The maximum permitted temperature of any adjacent combustible material is 65
o
C.
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Caution
It is imperative that the flue should be properly sealed where it passes through the roof, this can best be
achieved by using the approved method of roof flashing plate and cravat.
The flue outlet on all GUH heaters can be in either vertical or horizontal (top or rear) configuration.
Note
It should be noted that claims made under warranty and attributed to the ingress of water may not be
considered especially if an approved method of sealing has not been used, or if the design of the flue has
not made provision for possible condensation problems.
Where a horizontal outlet is used, the manufacturer strongly recommends that a flue venter of an
approved type is fitted to aid the evacuation of the combustion products.
It is also recommended that BS5854: 1980 and BS5440: parts 1 and 2 are used as a consultative
document when considering flue requirements.
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2.6 Electrical Installation
All electrical wiring and connections must be in accordance with the relevant European, National, and
Local regulations as well as to IEE Standards.
Warning
Ensure that the Electric and gas supplies are turned off before any electrical work is carried out on the
heater.
Also ensure that wiring cannot make contact with any metal surfaces liable to be subject to high
temperatures, and where insulation of the wiring could be impaired as a result of such contact.
All GUH models must be earthed.
Caution
The main electrical supply must not be switched off or disconnected as a method for stopping the heater,
the exception to this is in the event of an emergency, or when the heater has been allowed to cool
sufficiently to prevent any damage from being sustained to the heater or its controls (ie: during
servicing).
Claims for damage will not be considered if they have resulted from incorrect wiring or the incorrect use
of the heater
Each heater requires a permanent 230V 50Hz 1ph electrical supply, which must be wired through a fused
isolator fitted with a fuse of the correct rating (see section 7.1). The correct supply connection points for
the live, neutral, and earth are clearly indicated on the wiring diagram mounted inside the wiring box
cover.
Wiring diagrams are also detailed within this manual, (section 6.0 )
The electrical supply isolator should be mounted adjacent to the air heater in an easily accessible position
to allow for servicing isolation, or emergency shut off.
2.7 Electrical panel
Warning
Ensure that the mains isolator is turned OFF before undertaking any electrical on the heater.
Access to the electrical panel is gained by removing the right hand heater side panel, (Lift the panel clear
of the lower lip, pull panel outwards and let it slide until it is retained by the two lugs and the lower lip.
The panel can be fully removed by tilting one of the top corners towards the heater thereby disengaging
the lugs).
The cover to the electrical panel can be removed by undoing the two screws which secure it to the panel.
A copy of the wiring diagram is affixed to the inside of the cover .
Warning
Ensure that all connections are secure and that there are no loose strands which could bridge across the
terminals.
A minimum conductor size of 1.0mm (diameter) is required.
Caution
One electrical panel per heater is required, unless heaters are specified for multiple heater control
applications. On no account should more than one heater be connected to a single time switch or
thermostat. The only exception to this is when a control panel suitable for multiple heater applications is
supplied by the manufacturer, in which case the wiring diagram supplied with the control panel should be
read in conjunction with the existing wiring diagram.
Any ancillary electrical items e.g. room thermostats , time switches, remote panels etc, must be wired
into the heater electrical circuit in accordance with the diagrams provided
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
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Note
When external controls operate to switch the heater OFF, power to the heater should remain to allow the
fan to continue to operate to sufficiently cool the heater thereby preventing damage to the heat
exchanger.
2.8 Time switch
Caution
Time switches may only be fitted if they are of an approved type, and must have separate motor
connections, the motor must be connected to a suitable live and neutral supplies, and with the switching
contacts then wired in series from the neutral side of the room thermostat to terminal 7 .
Reference should be made to the wiring diagrams contained with the time switch, and within section 6.0
of this manual
2.9 Room thermostat
Any external room thermostat should be fitted with the common terminal (if fitted with changeover
contacts) to terminal 5.
If the thermostat is fitted with a heat anticipator this should be fitted to terminal 2.
The thermostat should be mounted at a height of approximately 1.5mm from the floor in an area where
the ambient temperature is representative of the area to be heated. The siting of the room thermostat
should be in a draught free area. or in an area where temperatures are free from the influences of direct
sunlight or heated discharged air.
2.10 Fan limit control
( Situated inside the right hand side panel)
Fan control (white button)
The fan control switch features normally open 230V contacts, and is wired to control the live supply to
the fan motor . When the circuit is made, the fan will switch on when the heat anticipator has closed the
fan switch contacts. When the thermostat or time switch shuts down the burner, the fan will continue to
run until the thermal switch has cooled sufficiently to prevent the residual heat from damaging the heater
or its controls.
On startup the fan delay prevents air being circulated until the desired temperature is achieved
Limit control (red button)
An adjustable high temperature manual reset limit control. If this control needs resetting the cause should
be determined and rectified immediately.
On models with two fans a second limit control is situated inside the left side panel and is wired in series.
Operation of either switch will shut down the heater
On the 400 with 4 fans a further 2 limit sensors are fitted and they are linked to the relevant control
Caution
The power supply to the fan must not be interrupted, the only time when power supply can be
disconnected or interrupted is during servicing or in emergencies.
If there is a requirement for the heater to be switched off over night then the gas valve circuit should be
opened via a time switch, etc, as per the wiring instructions and diagrams supplied within section 6.0 of
this manual.
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 20 of 41
2.11 Summer switch
A heat / ventilation switch may be fitted remotely and connected between terminals 9. and 4.
This switch will allow the fan motor to run continuously. Where the remote control box is used, the
burner is automatically inhibited during the summer / ventilation setting.
2.12 Gas installation
Warning
Only qualified and competent personnel are allowed to undertake the installation, commissioning, and
servicing of Unit Heaters
The GUH propane range of heaters are all manufactured and pre set for use with Propane Gas, and all
feature 3/4” BSP connection points. Prior to installation the supply characteristics (gas type and pressure)
must be checked to ensure that they are in accordance with the data plate on the heater.
The gas supplier should check that the meter and service connection to the heater are capable of
delivering the required volume of gas, thereby ensuring that the minimum burner pressure can be
achieved. Consideration should be given to the pressure drop on single and multi heater installations and
the effect they may have on other plant sharing the supply.
If it is necessary to fit a gas pressure booster, the controls must include a low pressure cutoff switch
which must be fitted on the supply / inlet side of the booster. It is also a requirement that the gas supplier
is advised prior to the installation or fitting of the booster.
Each heater supply must be fitted with a separate isolating cock positioned adjacent to and upstream of
the union which must be sited outside the heater.
An approved gas jointing compound must be used on all joints and unions and the system purged and
tested for soundness prior to final connection
The connection to the heater can be made by way of either an approved flexible coupling or rigid
connection . Threaded connections must comply to ISO 288/1 or ISO 7/1 further information concerning
accepted European practice is detailed in June 1995 version of prEN1020 Annex 7.
The diameter of the pipework from the isolating cock to the burner must not be less than the diameter of
the connection into the multiblock.
Note
Reference to The Institute of Gas Engineers publications Utilisation Procedures IGE/UP1 and IGE/UP2
together with reference to BS6891 is strongly advised.
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 21 of 41
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 22 of 41
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 23 of 41
3.0 Commissioning
Note
It is a requirement that only suitably qualified and competent personnel are allowed to undertake the
commissioning of the heater.
It is also strongly recommended that prior to commissioning the engineers familiarises themselves with
the heater. the specific requirements of the installation /application, and the information contained within
the manual.
Warning
All heaters are subject to a rigorous test programme prior to despatch, whilst such a programme does
involve pre-commissioning and the setting of the heater to operate efficiently and within its designed
operational limits this does not mean that the function of thorough on site commissioning is less
important
It is strongly recommended that the equipment used for the sampling and analysis of the flue gases is
accurate to within +/- 0.1% and maintained so that it is regularly calibrated.
The following pre-commissioning checks should be undertaken, having first ensured that the gas and
electrical supplies are turned off.
(a) Check that all panels and fasteners are secure and in place.
(b) Check that the heater is mounted safely.
(c) Check that the flue is sealed, secured, and adequately supported.
(d) Check that the fan is free to rotate, that the fan is secured to its shaft, and that the guards and fan
assembly are all in place and properly secured.
(e) Check that the heater is installed so that it is not tilted and remains square.
(f) Check that the outlet louvers are set to offer minimum resistance to air flow.
3.1 Electrical pre-tests
The electrical safety checks must include the following
a) Test for earth continuity
b) Test for resistance to earth
c) Check live and neutral connections are correct.
d) Check to ensure that when the external controls operate to switch the heater off, power remains to the
fan
3.2 Gas supply pre-test
Ensure that the service pipework has been installed purged and tested in accordance with the relevant
regulations, and that the installation is served by an adjacent isolating cock.
Connection from the supply to the heater must also comply with the relevant regulations (see section 8.0)
and must have been purged and soundness tested by an authorised engineer.
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 24 of 41
3.3 Ignition sequence manual versions
Warning
If during the following sequence of operations the heater fails to operate correctly the fault should be
traced and rectified before proceeding, if necessary referring to section 5.0 fault diagnosis. If for any
reason the pilot light is extinguished no attempt should be made to re light it within three minutes
a) Switch off the main electrical supply to the heater
b) Turn off gas supply to the heater
c) Remove side panel, and connect manometers to the gas supply test point and to the main burner test
point
d) Ensure outlet louvers are correctly set
e) Ensure fan rotation is not impaired or obstructed
f) Set room thermostat to its lowest setting
g) If a time switch is fitted ensure it is set to an on period
h) Switch on electrical supply
i) Turn on gas supply, and open burner viewing port
j) Depress and hold in control start button and test for soundness
k) Continue to depress start button whilst operating igniter until pilot light is present
l) Hold in start button for at least one minute to establish pilot - carefully release button confirming
presence of pilot
Warning
If the pilot fails to become established do not attempt to re light for at least three minutes , if the pilot is
established continue as follows :-
m) Close burner viewing port
n) Turn thermostat to the highest setting, and the main burner will light then re-open the viewing port and
check that the main burner is providing a good flame i.e. even, stable, and conical.
o) Check pressure readings on the manometers, and continue to let the heater fire for ten minutes
p) When the fan starts ensure that the direction of rotation is correct , and that the fan start is within two
minutes of burner ignition
Caution
If the fan fails to operate within approximately two minutes and the heater goes to overheat it will shut
down through breaking the circuit to the gas valve, the cause must be ascertained and rectified before reignition.
Once the limit thermostat has tripped out it must be manually reset to allow re-ignition to take place.
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 25 of 41
q) After ten minutes check burner head pressure is as specification - adjust as necessary by removal of
the gas pressure adjustment cover, and using a screwdriver turn the adjustment screw on the governor as
follows: Anti clockwise to reduce. Clockwise to increase.
r) Check that the gas pressure remains satisfactory for all appliances on the same circuit
s) Undertake combustion tests checking CO CO
2
and efficiency (see section 7.0) check for spillage using
a dry, water cooled ,rhodium or chromium plate.
t) Check that the burners are extinguished when the thermostat is set to its lowest setting, and then
remove the manometers.
u) Turn the thermostat to its highest setting to re light the burner and replace the adjustment screw cover
v) Check flame failure circuit by loosening the connection between the thermocouple and the overheat
limit control on the main gas valve, the ignition and main burners should go out, retighten after testing
w) Turn the thermostat to its lowest setting and shut off the gas supply at the gas control valve, allow the
fan to continue to run until the heater is cooled sufficiently for the fan to shut down
x) Turn off the electrical supply
y) Set thermostat to desired room temperature and replace the side cover panel
z) Ensure that the user is familiar with the heater and its controls and that the user is satisfied with the
commissioning and testing, and that he is aware of the instructions within the manual
It is strongly advised that the commissioning engineer runs through the lighting, shutdown, and general
safe and efficient running of the heater before hand over.
3.4 Ignition sequence automatic versions
Automatic control is by way of a Satronic controller (with automatic gas valve replacing the manual
standing pilot valve) used in conjunction with a Satronic spark generator (which replaces the piezo
igniter as fitted to manual units) , giving a maximum pilot sequence of 15 seconds.
Flame supervision is via a flame sensor rod. instead of the thermocouple as fitted to the manual units.
The sequence is as follows: as per 3.3 a- i
The start signal will ignite the pilot, once the flame proving has taken place the main gas valve will
supply the burner and burner ignition will occur.
Continue as per 3.3 m-y
3.5 Hand over
Upon satisfactory completion of commissioning and testing, the customer should receive the completed
guarantee and commissioning card (section B) from the commissioning engineer together with the user
instructions (section C).
At the same time the user should be made aware of the most efficient and economical methods of
operation.
The user must be familiar and satisfied with the safety, ignition, shutdown, and general operational
procedures.
4.0 Servicing
Warning
It is a requirement that only qualified personnel are allowed to carry out installation commissioning or
servicing.
In addition only spare parts recommended by the manufacturer may be fitted, and the installer should
provide a list of recommended spare parts that are available through the manufacturer or his agent (see
section 9)
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 26 of 41
Before commencing any maintenance or servicing work the heater must be shut down and allowed to
cool, and have the gas and electric supplies to it turned off at the supply cock and isolator respectively.
Always test for gas soundness after completing any service work particularly if this has
necessitated the removal and / or replacement of gas carrying components
It is advisable that routine inspections are carried out on a frequent basis, servicing must also be carried
out regularly, and in accordance with the manufacturers recommendations i.e. at a maximum interval of
one year. In certain applications the frequency of servicing will have to be increased, this to a large extent
is governed by the working environment, and both the manufacturer and the installer will be able to offer
further advice.
A safe working platform giving good access to the heater is required, It should be noted that on
suspended units the lower front panel is removable so as to provide access to the burner tray, injectors,
and manifold, all of which should serviced in the normal way as detailed.
Clean all accessible surfaces including the outside of the heat exchanger by removal of the fan assembly
and the louvres. Check for panel damage and that all fasteners are present and secure.
Visually check all electrical wiring for signs of damage, possibly through contact with hot surfaces,
check conduit for signs of chaffing and for security . Check all terminals are secure and free from
escaped / stray conductor strands.
4.1 Servicing procedure - major component parts
Heat exchanger
Remove louvres and fan assembly and carry out visual inspection of the heat exchanger using an
inspection lamp and mirror. Check seams and joints for perforations. Check for severe corrosion and
splits in the body in the body of the heat exchanger.
Check that there are no blockages and that there is not an excessive build up of soot within the heat
exchanger.
If required remove the down draught diverter and burner tray allowing access for cleaning, with a
flexible flue brush and vacuum cleaner.
Warning
If the heat exchanger is found to be perforated the heater must not be fired until a replacement heat
exchanger has been fitted
Burner Pilot
Remove the right hand side panel. Disconnect the pilot gas feed at both the gas valve and pilot bracket.
Disconnect the piezo HT lead from the terminal. Unscrew the thermocouple retaining nut from the pilot
bracket and withdraw the thermocouple. Remove the two retaining screws and withdraw the pilot bracket
assembly. Clean the thermocouple. pilot bracket and pilot burner ports with a fine wire brush and / or lint
free cloth if necessary using acetone
Caution
Where pilot gas lines are of copper aluminium or bundy tube feed pipes should be undone at both ends to
prevent undue stressing and the risk of premature failure.
Burner Tray
Caution
Burner tray cannot be removed with the pilot assembly in place
Remove the two screws from the hinged front panel and open the panel fully. Remove the two burner
tray fixing screws located on the right hand side inner panel. Pull tray forward and if required clear of the
heater. Clean the burner ports with a vacuum cleaner, fine wire brush, and / or lint free cloth and
acetone. Visually inspect the burner ports ensure that they are all clean and unrestricted , if necessary
using compressed air to carefully dislodge and remove any foreign matter.
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 27 of 41
Injectors and Manifold
With the pilot bracket assembly removed and the burner tray either fully withdrawn or pulled forward by
at least 100mm the manifold and injectors can be removed by using the following procedure. Release the
union between the gas valve and the flange, remove the four flange fixing screws. Rotate the manifold so
that the injectors are aligned with the keyhole and carefully withdraw the manifold complete with the
injectors through the right hand side panel.
Check that the manifold is straight, the injectors are correctly aligned, and that they are clean, and that
there are no contaminates restricting the orifices, if necessary clean carefully with compressed air and or
lint free cloth and acetone.
Caution
The injector orifice is precision machined to fine tolerances, do not clean with hard sharp or abrasive
instruments. If the injectors have been removed from the manifold, when they are replaced, the copper
washers must be refitted, and care should be taken not to overtighten. Ensure all joints are gas tight.
Fan and Motor
Check that the fan is secure and rotates freely without excessive play in the shaft. The fan blades and
motor should be cleaned using a soft brush. The fan and motor assembly can be removed from the heater
by first disconnecting the leads from the terminal block and by removing the strain relief bush. The four
screws securing the fan and motor assembly to the rear of the plenum can be removed, and the assembly
complete with guard can then be removed from the heater.
Fan and Limit Thermostats
Lower the right hand panel, on twin fan units the left hand side panel will also have to be lowered, so as
to gain access. Remove securing screw from cover, remove cover plate and disconnect the cables.
Remove the screws which secure the unit to the side of the heater and withdraw the thermostat complete
from the heater.
Check that the bi metal coil and its housing are secure clean as necessary with a soft brush .
Flue System
Check that the flue is in good condition, that it is adequately supported, that there are no blockages or
restrictions, and that there is a positive draw . Check that any joints are properly sealed preventing an
escape of products of combustion. Check condensate drain if fitted . Check for signs of water ingress and
any resultant damage.
Test
Test and re-commission as per sections 3.0 to 3.4 inclusive.
Automatic Controls
Automatic control is by way of a Satronic controller (with automatic gas valve replacing the manual
standing pilot valve) used in conjunction with a Satronic spark generator (which replaces the piezo
igniter as fitted to manual units) , giving a maximum pilot sequence of 15 seconds.
Flame supervision is via a flame sensor rod . instead of the thermocouple as fitted to the manual units.
Check the flame sensor rod for signs of pitting or corrosion, ensure that the ceramic insulation material is
not damaged or cracked. Check connections are secure.
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 28 of 41
5.0 Fault Diagnosis
Fig 19
Fig 20
Fig 21
Pilot
Burner fails
to light
No Spark
Air in Gas
Supply
Check HT leads &
Connectors Check
Spark Ignitor
Pilot Feed
Restriction
Purge Gas Line to
Remove Air
No Gas
Supply
Check Pilot
Adjuster is Fully
Open and that the
Pilot Tubes are not
blocked
Check Gas Supply
is Present and that
Gas Taps are open
Pilot
Burner
lights and
becomes
established
but the
Main
Burner fails
to light
Pilot
Burner
Lights but
flame does
not become
established
Pilot Flame not
being sensed by
Thermocouple
Check that the Pilot
Flame Path is
supplying Heat to the
Thermocouple
Pilot Flame is too
small
Check that the
Thermocouple is
Connected to the Gas
Valve Correctly
Check that the Pilot
Flame Adjuster is
correctly set and that
the pilot feed is
Unrestricted
Reposition
Thermocouple
and / or Pilot
Flame Shroud
Replace Faulty
Thermocouple
Check that all
External
Controls are set
to Demand Heat
Check that
there is Power
to the Heater
Check Limit
Stat Reset
Check Fuse
Check
Thermostat
Check Time
Switch
Check that the
Gas Valve is not
Open Circuit
Replace
Gas Valve
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 29 of 41
Fig 22
Fig 23
Fig 24
No
Operation
Check that Limit
Stat is not in Fail
Safe Position
Check Stat
Check
Timer
Check External
Controls are
Demanding Heat
Check there is
power to the
Heater
Check Fuse
Pilot Will
Not Light
No Spark
Air in Gas
Supply
Pilot Line
Restricted
No Gas
Supply
Check Electrode
Gap is Correct
Purge System to
Remove Air
Check that Pilot
Adjuster is set
Correctly
Check Gas taps
are open and Gas
is Present
Check Electrode
is not Cracked
Check HT leads
and Connectors
Check Spark
Generator
Check Control
Box
Replace Faulty
Unit
Pilot lights
but fails to
become
Established
Poor Signal
from Probe
Check
Flame Path
Check Probe
Signal
Faulty
Control Box
Pilot Flame
to Small
Replace
Faulty Probe
Replace
Faulty Unit
Check Pilot
Flame Adjuster
is Fully Open
and Pilot Feed is
Unrestricted
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 30 of 41
Fig 25
Manual and Automatic Operation
Fig 26
Fig 27
Pilot flame
is
Established
but Main
Burner will
not Ignite
Faulty Wiring
from Control to
Valve
Replace
Faulty Control
Unit
Faulty Second
Stage Valve
Fan will not
Run
Fan Control
is Open
Circuit
Check that Fan
will run when
Main Gas is
On
Replace
Faulty Fan
Control
Open Circuit to
Fan Motor
Check Wiring and
Connections
Fan runs
but stops
when Main
Burner is
ali
g
ht
Faulty Motor
Fan Control is
Open Circuit
Low Ambient
Temperature
Check that
Fan will run
when Main
Gas is On
Check that
Fan cycles
On / Off.
Check Fan
Button,
Check Fan
Stat Settings
Replace
Faulty Unit
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 31 of 41
6.0 Wiring Diagrams
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
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GUH RANGE PROPANE GAS FIRED UNIT HEATERS
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GUH RANGE PROPANE GAS FIRED UNIT HEATERS
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GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 35 of 41
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 36 of 41
7.0 Technical Data
Formulae for calculating efficiency are detailed as follows
q1 is the heat of the dry products of combustion (% of heat released per unit volume of gas)
q2 is the heat of the water vapour contained in the products of combustion (% of heat released per unit
volume of gas)
C
1
is the mean specific heat of the dry products of combustion (in MJ / (m3K)
t1 is the average combustion air temperature (in
o
C)
t2 is the average temperature of the products (in
o
C)
H
i
is the net calorific valueof the gas at 1013 mbar and 15oC, dry (in MJ / m3)
H
s
is the gross calorific value of the gas at 1013 mbar and 15oC, dry (in MJ / m3)
Vf
is the volume of dry products of combustion per unit volume of gas (in m3)
Vf is calculated from the volume of CO
2
(
V
CO2) produced by the combustion of 1m
3
of gas (see table
below), and
from the CO content of the products of combustion (
V
CO2M)
VCO
2
Vf = ---------------- x 100
V CO
2
M
Ref Gas G110 G120 G20 G25 G30 G31
V CO2 0.26 0.32 1 0.86 4 3
The net efficiency , E (net) (in % ) is given by : E (net) = 100 + (q1 = q2)
Where t
2
– t
1 Hs
- H
i
q1 = C1 x Vf ------------------ x 100 q2 = 0.077 ------------------- (t2 – t1)
H
i
Hi
7.1 Technical Data Common Information
Gas supply Types
I
3P
Destinations BE FR GB IE NL
Appliance Type B11
PIN / report no 63AQ0533 / 160009
Electrical Supply 230V 50Hz 1ph
Fuse Rating 6 / 10 AMP
IP Rating IP44
Fan Limit Settings Fan On 60ºC Fan Off 30ºC Limit 100ºC
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 37 of 41
7.2 Unit Heater Models Technical Data
MODEL PROPANE
GAS
GUH100 GUH125 GUH165 GUH205 GUH250 GUH400
HEAT
OUTPUT
kW
Btu
29.3
100,000
37.0
126,250
48.4
165,140
61.6
210,180
73.3
250,000
117.3
400,000
HEAT INPUT
(Gross)
kW
Btu
37.5
128,000
47.5
162.500
62.3
212.600
79.2
270,300
93.5
319.000
151.0
515,000
MIMIMUM INLET
PRESSURE
mbar
Ins WG
37
14.8
37
14.8
37
14.8
37
14.8
37
14.8
37
14.8
BURNER
PRESSURE
mbar
Ins WG
36
14.5
36
14.5
36
14.5
36
14.5
36
14.5
36
14.5
PROPANE GAS
CONSUMPTION
ft
3
/hr
m
3
/hr
51
1.4
65
1.8
85
2.4
108
3.0
127
3.6
216
6.0
TEMPERATURE
RISE
ºC
ºF
33
91
32.6
90
32.5
90
33
91
34.3
94
33
91
AIR
FLOW
ft
3
/min
m
3
/sec
1528
0.721
1860
0.878
2485
1.173
3060
1.444
3530
1.666
6120
2,888
AXIAL FAN
THROW
ft
mtrs
50
15.5
55
17.1
65
20.2
65
20.2
70
21.7
65
20.2
CENTRIFUGAL FAN
STATIC PRESSURE
Pa
Ins WG
100
0.4
125
0.5
163
0.65
125
0.5
125
0.5
150
0.6
SOUND LEVEL
Dba 63 69 72 72 72 72
GAS CONNECTION
BSP 3/4 3/4 3/4 3/4 3/4 2 x 3/4
MAIN INJECTOR
PROPANE GAS
mm
No Off
1.3
5
1.3
6
1.3
8
1.3
10
1.3
12
1.3
20
FLUE DIAMETER
mm 150 175 200 200 250 300
ELECTRICITY SUPPLY
230/1/50 230/1/50 230/1/50 230/1/50 230/1/50 230/1/50
ELECTRICAL POWER
(AMPERES)
Axial
Cent
1.1
0.63
1.7
0.85
1.7
1.050
2.0
1.26
2..1
8.4
4.4
9.6
FUSE RATING Axial
Amps 6 6 6 6 6 10
POWER ABSORPTION
Kw
Axial
Cent
0.15
0.63
0.36
0.85
0.36
1.05
0.3
1.26
0.3
1.26
1.1
2.1
AIR OUTLET
VENTILATION AREA
cm
2
in
2
169
26
215
34
275
43
313
49
346
54
475
72
MOUNTING HEIGHT
(MTRS)
Min
Max
2.12
3.03
2.42
3.33
2.73
3.94
2.73
3.94
2.73
3.94
2.73
4.24
GROSS FLUE TEMP
ºC 170 180 170 180 170 140
WEIGHT
Kgs
Axial
Cent
107
120
123
136
155
175
188
216
218
246
386
442
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 38 of 41
8.0 Reference Information
Doc/Ref Title/Subject
prEN 621 Non Domestic Gas Fired Forced Convection Air Heaters For Space Heating
BS EN 292 Parts 1 and 2; 1992 Safety of Machinery
BS EN 60204 Part 1; 1993 Safety of Machinery - Electrical
BS EN 60335 Part 1; 1988 Safety of Electrical Appliances
BS EN 55014 1993 Electromagnetic Compatibility
BS EN 50165 1995 Safety of Electrical Equipment
BS 5854 1980 Code of Practice - Flues/Flue Structures
BS 6891 1988 Installation of pipework < 28mm
BS 715 1993 Metal Flue Pipes and Fittings
BS 5440 Part 1 ; 1990 Specification/Installation of Flues
BS 5440 Part 2 ; 1989 Ventilation Requirements Gas Appliances
ISO 228/1 See also BS 2779 and BS 5380) Pipe Threads Seals and Couplings
UP / 1 Replaces IM / 5 and IM / 16 Installation of Gas Appliances
UP / 2 Replaces IM / 7 Installation of Gas Appliances
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 39 of 41
9.0 Parts list
Part Description GUH 100 GUH 125 GUH 165 GUH 205 GUH 250 GUH 400
Heat Exchanger Assy 33-10-600 33-10-601 33-10-602 33-10-603 33-10-664 33-10-603
Draught Diverter Assy 33-20-559 33-20-606 33-20-607 33-20-611 33-20-665 33-20-611
Gas Train Assembly Rhs 33-20-263 33-20-264 33-20-265 33-20-266 33-10-683 30-20-266
Gas Train Assembly Lhs N/A N/A N/A N/A N/A 33-10-712
Pilot Installation Rhs 33-30-330 common common common 33-30-330 33-30-330
Pilot Installation Lhs N/A N/A N/A N/A N/A 33-10-713
Control Box Assembly 33-20-326 common common common 33-30-326 33-10-716
Flue Kit Assembly N/A N/A N/A N/A N/A 33-21-155
Control Box Lid 33-20-865 common common common 33-20-865 33-20-865
F & L Stat L4064 8” 28-60-023 common common common 28-60-023 28-60-023
Limit Thermostat (IMIT) N/A N/A N/A 28-40-059 28-40-059 common
Choke Plate Weld Assy 33-30-240 common common common 33-30-240 33-30-240
Manifold Assy Rhs 33-10-151 33-10-152 33-10-153 33-10-154 33-10-682 33-10-154
Manifold Assy Lhs N/A N/A N/A N/A N/A 33-10-715
Copper Washer 91-00-052 common common common 91-00-052 91-00-052
Injector Prop Gas 33-30-316 common common common common common
Gasket 33-30-295 common common common 33-30-295 common
Gas Valve(Honeywell) 28-30-114 common common common 28-30-114 28-30-114
Pilot Burner c/w shear olive 28-90-148 common common common 28-90-148 common
Pilot Injector 28-90-165 common common common 28-90-165 28-90-165
Thermocouple 33-50-004 common common common 33-50-004 35-50-004
Ignition Electrode 28-90-156 common common common 28-90-156 common
Ignition Lead 28-02-172 common common common 28-02-172 28-02-172
Burner 33-00-124 common common common 33-00-124 common
Fuse Holder 28-07-050 common common common 28-07-050 28-07-050
Fuse 10 x 38 Axial 28-07-048 common common 28-07-048 28-07-048 28-07-049
Fuse 10 x 38 Centrifugal 28-07-048 common common 28-07-048 28-07-048 28-07-051
Fan/Motor Guard Assy Axial 28-09-039 28-09-040 28-09-036 28-09-042 28-09-042 28-09-042
Fan/Motor Guard Assy Cent 28-09-001 28-09-001 28-09-002 28-09-001 28-09-001 28-09-002
Fan Plenum Axial 33-10-540 33-10-554 33-10-528 33-10-567 33-10-670 33-21-154
Fan Plenum Cent 33-00-167 33-00-166 33-00-165 33-00-161 33-10-672 33-10-706
*Down Flow head 30 Deg
33-10-427 33-10-428 33-10-429 33-10-430 33-10-678 33-10-430
*Down Flow Head 90 Deg
33-20-504 33-20-505 33-20-506 33-20-507 33-10-675 33-20-507
*Vertical Louvre
33-20-873 common common common 33-20-873 common
*CP2 Control Panel
33-10-424 common common common 33-10-424 common
*Flue Ventor Assy
33-20-752 33-20-753 33-20-754 common 33-20-754 TBA
* Items marked are available as Optional Extras
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 40 of 41
S E C T I O N C
B A S I C U S E R
I N S T R U C T I O N S
10.0 Introduction
The following information is relevant to the Gas
fired GUH Cabinet Heater range manufactured
by Benson Heating. These heaters are
manufactured within a strictly controlled quality
system to ISO 9001.
All Benson Heating Cabinet Heaters are CE
marked, having been found to satisfy the
essential requirements of the following
European Directives.
Machinery Directive (89/392/EEC)
Low Voltage Directive (73/23/EEC &
93/68/EEC)
Electromagnetic Compatibility Directive
(89/336/EEC & 91/31/EEC)
Product Liability Directive (65/374/EEC)
Benson Heating support all new products being
supplied to their customers with a
comprehensive information pack, and it is the
responsibility of the owner, user, or hirer, of
such products supplied by Benson Heating to
ensure that operators are provided with the
operator manual, and that they are suitably
instructed regarding the purpose of the manual
and safety instructions. In addition to this,
operators must also be suitably and adequately
trained in the use of the product.
Contained within the text of this manual, the
words 'Caution' and 'Warning' are used to
highlight certain points.
Caution is used when failure to follow or
implement the instruction(s) can lead to a
premature failure or damage being occasioned to
the heater or its component parts.
Warning is used when failure to heed or
implement the instruction(s) can lead not only to
component damage, but can also lead to a
hazardous situation being created where there is
a risk of personal injury or death
10.1 Commissioning and hand over
Warning
As part of the commissioning programme, the
commissioning engineer must go through the
following with the operator.
(i) Lighting, shutdown, and operational
information.
(ii) Safety features, data plate, and labelling.
(iii) The requirement for regular inspection especially if the heater is within a more
demanding environment - and the need for
regular servicing, carried out by competent and
qualified engineers.
Caution
After approximately 100 hours of running, the
tension on the fan belts must be checked to
ensure that it is correct, and that the belts have
not stretched.
It is strongly advised that this is undertaken by
the commissioning engineer, and not the
operator.
10.2 Servicing
Warning
Servicing must be carried out on a regular basis,
the maximum interval between services being
one year.
It is a requirement that only suitably qualified
and competent persons are allowed to undertake
the servicing.
Benson Heating advise that the planned service
schedule as detailed in section 4.1 of the
Installation, Commissioning and Servicing
Manual is adopted by the user.
Further details are available from either Benson
Heating or from the commissioning engineer.
10.3 Start up procedure
Warning
If during the following sequence of operations
the heater fails to operate correctly the fault
should be traced and rectified before
proceeding, if necessary referring to section 5.0
fault diagnosis. If for any reason the pilot light
is extinguished no attempt should be made to
re light it within three minutes
a) Switch on electrical supply
b) Turn on gas supply, and open burner viewing
port
GUH RANGE PROPANE GAS FIRED UNIT HEATERS
Page 41 of 41
c) Depress and hold in control start button
whilst operating igniter until pilot light is
present
d) Hold in start button for at least one minute to
establish pilot - carefully release button
confirming presence of pilot
Warning
If the pilot fails to become established do not
attempt to re light for at least three minutes , if
the pilot is established continue as follows.
e) Close burner viewing port
f) Set the thermostat to the highest setting, and
the main burner will light then re-open the
viewing port and check that the main burner is
providing a good flame i.e. even, stable, and
conical.
Caution
If the fan fails to operate within approximately
two minutes and the heater goes to overheat it
will shut down through breaking the circuit to
the gas valve, the cause must be ascertained and
rectified before re-ignition.
Once the limit thermostat has tripped out it must
be manually reset to allow re-ignition to take
place.
g) Set controls as required
10.4 Ignition sequence automatic
versions
Automatic control is by way of a Satronic
controller (with automatic gas valve replacing
the manual standing pilot valve) used in
conjunction with a Satronic spark generator
(which replaces the piezo igniter as fitted to
manual units) , giving a maximum pilot
sequence of 15 seconds.
Flame supervision is via a flame sensor rod.
instead of the thermocouple as fitted to the
manual units.
The sequence is as follows: as per 10.3
The start signal will ignite the pilot, once the
flame proving has taken place the main gas
valve will supply the burner and burner ignition
will occur.
10.5 Stop procedure
(a) Set controller to off position.
(b) The fan motor will continue to run until heat
dissipation allows the fan and limit stat to shut
down the fan.
Caution
Do not use the main electrical isolator to turn off
the heater, to do so can cause damage to the heat
exchanger and combustion chamber, and
thereby invalidate the warranty.
10.6 Shut down procedure
(
a) Follow steps 10.5 (a) and (b), when fan
stops turn main electrical isolator off, and shut
gas supply cock
10.7 Ventilation only
(
a) Set heat/ventilate switch to 'ventilate'.
10.8 Lockout situations
If either the burner or the fan and limit stat go to
lockout, the lockout must be cleared manually
before the ignition sequence can be re-initiated.
Caution
Repeated or frequent lockouts must be
investigated and their cause determined by a
qualified and competent engineer.
10.9 Contact information
Further information is available from :-
Benson Heating
Ludlow Road
Knighton
Powys
LD7 1LP
Telephone 01547 528534
Facsimile 01547 520399
Benson Heating is a Division of Benson
Climate System
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