SEELEY INTERNATIONAL AIRA GDH Owner's manual

INSTALLATION AND OPERATION
GDH
Original English Instructions

AIRA DIRECT FIRED GAS HEATING INSTALL OPERATION MAINTENANCE MANUAL |1
SAFETY
1.0 Introduction 3
1.1 General Safety Information 3
1.1.1 Handling the Heater 3
1.1.2 Positioning the Heater 3
1.1.3 Combustibles 3
1.1.4 Wiring Electrical 4
1.1.5 Occupational Health and Safety 4
1.1.6 Gas Piping 4
1.1.7 Commissioning, Recommissioning
and Decommissioning 4
1.1.8 Operational Safety 4
1.1.9 Gas Compliance 4
1.1.10 Safety Points to Consider 5
General Information
2.1 Unit Overview 6
2.2 Equipment receipt 6
2.3 Factory unit test 6
2.4 Technical specication 7
2.4.1 Unit and Component Identication 7
2.4.2 Construction 7
2.4.3 Blower/Fan 7
2.4.4 Dampers 7
2.4.5 Electrical Control 7
INSTALLATION Information
3.0 Installation Information 8
3.1 MODEL VARIATIONS AND DIMENSIONS 8
3.2 Installation 10
3.2.1 Location 10
3.2.2 Clearance Around Unit 10
3.2.3 Weight And Location 11
3.2.4 Lifting 11
3.2.5 Positioning and Securing 11
3.2.6 Duct Connections 11
3.3 ELECTRICAL CONNECTIONS 12
3.3.1 Electrial Supply 12
3.3.2 User Control Conguration Optionsit 12
3.3.3 Blower / Fan Setup 13
3.4 GAS CONNECTIONS 13
3.4.1 Gas Supply 13
3.4.2 LPG 13
3.4.3 Gas Train Information 13
3.4.4 Gas Valve 14
3.4.5 Standard Operating Pressure of the Gas Valve 15
3.4.6 Setting Gas Valve Pressure 15
3.4.7 Setting the Modulating Valve Motor 15
3.4.8 Pilot Injector Setup 17
3.4.9 Leaving Air Temperature Sensor 18
COMMISSIONING INFORMATION
4.0 COMMISSIONING 19
4.1 Unit Details 19
4.2 General Installation Check 19
4.3 Electrical Checks 20
4.4 Gas Checks 20
4.4 1 Incoming Gas Supply Checks 20
4.4.2 Gas Train Check 20
4.4.3 Setting the Modulating Valve Motor 21
4.4.4 Modulating Motor Operational Check 21
4.5 Setting Controls 22
4.5.1 Leaving Air Temperature Control 22
4.5.2 Thermostat and User Controls 22
4.5.3 Setting Air Pressure Switch 22
4.6 General operation 23
4.7 COMBUSTION PRODUCT TESTING 24
4.8 COMMISSIONING RESULTS 24
OPERATING INSTRUCTIONS
5.0 OPERATING INSTRUCTIONS 25
5.0.1 Startup – Rotary swith units to provide heat 25
5.0.2 Startup - Rotary switch units to provide ventilation 25
5.0.3 Startup -Rotary switch units to provide cooling 25
5.0.4 Shutdown - Rotary switch units providing heat 25
5.0.5 Shutdown - Rotary switch units providing ventilation 25
5.0.6 Shutdown - Rotary switch units providing cooling 25
5.1 BMS STARTUP AND SHUTDOWN 25
5.2 Operational owchart 26
UNIT MAINTENANCE
6.0 Service and Maintenance 27
6.1 BURNER MAINTENANCE 27
6.2 Major Service/component replacement process 28
6.2.1 Electrical Components 28
6.2.3 Casing Components 30
6.3 Fault Finding 31
6.4 Replacement Parts List 31
Appendix
A: AGA TYPE B INFORMATION 32
B: ELECTRICAL INFORMATION 33
B1: Single speed motor rotary 33
B2: Two speed motor rotary 33
B3: Single speed motor bms 34
B4: Two speed motor bms 34
C: Gas Train Information 35
D: COMMISSIONING REPORT 36
E: MAINTENANCE 38
E1: Maintenance Schedule 38
E2: Monthly Maintenance Check 39
E3: Maintenance Checklist 40
F: WARRANTY INFORMATION 42
G: RELEASE INFORMATION 44
CONTENTS

AIRA DIRECT FIRED GAS HEATING INSTALL OPERATION MAINTENANCE MANUAL |3
1.0 INTRODUCTION
This Manual is for use with a Seeley International manufactured AIRA GDH Heater Only. This manual is updated
without notication and it is the installer and customers responsibility to ensure the latest version is used. This Manual
is intended to assist in the Installation, Commissioning and Service of Seeley International manufactured GDH units
and DOES NOT take precedence over any Australian Standards or legislation.
This book should be retained with the unit or made easily accessible to installation and maintenance personnel.
AIRA GDH units are a direct red heater. AIRA GDH units are produced in 5 di󰀨erent capacities to suit a wide variety of
installation requirements and can be paired with AL coolers to provide a combined heating and cooling solution.
1.1 GENERAL SAFETY INFORMATION
THIS HEATER IS TO BE INSTALLED BY AN AUTHORISED PERSON ONLY
DO NOT Operate this appliance before reading the manual.
DO NOT Place articles on or against this appliance.
DO NOT Use or store ammable materials within 1200mm of this appliance.
DO NOT Operate this appliance with panels, covers or guards removed.
DO NOT Spray aerosols in the vicinity of this appliance while it is in operation.
DO NOT Remove markings and or labels from the unit.
DO NOT Remove warning labels from the unit.
DO NOT Restrict relief area
These AIRA GDH units must be installed in accordance with these instructions, local gas tting regulations, municipal
building codes, electrical wiring regulations, Australian Standard AS/NZS 5601 Gas Installations and any other relevant
statutory requirements.
Employers and Employees Responsibility
The installation and maintenance of gas ducted
heating units, particularly at height, has the potential
to create Occupational Health and Safety (OH&S)
issues for those involved. Installers are advised to
ensure they are familiar with relevant State and Federal
legislation, such as Acts, Regulations, approved
Codes of Practice and Australian Standards, which
o󰀨er practical guidance on these health and safety
issues. Compliance with these regulations will require
appropriate work practices, equipment, training and
qualication of workers. Seeley International provides
the following information as a guide to contractors and
employees to assist in minimising risk..
Risk Assessment
A risk assessment of all hazardous tasks is required under
legislation. A risk assessment is an essential element that
should be conducted before the commencement of work,
to identify and eliminate the risk of falls and other risks, or
to minimise these risks by implementing control measures.
This does not need to be a complicated process - it is a
matter of assessing the job to be done and considering
what actions are necessary so the person doing the job
does not injure themselves.
This should be considered in terms of:
• What are the chances of an incident occurring?
• What could the possible consequences be?
• What can be done to reduce, or better still, eliminate
the risk?
1.1.1 Handling the Heater
GDH units are to be handled as ductwork. The unit should be transported stored and handled so that the main
enclosure is supported and not deformed, and care taken to place minimal strain upon the gas components.
1.1.2 Positioning the Heater
The unit should be installed so that it is level. GDH units may be installed vertically if custom ordered to do so. At least
1000mm clearance shall be left either side of the heater to allow su󰀩cient access to the controls and to the access
panel for maintenance purposes. Airow across the heater is required for operation and ensuring emissions fall within
the required limits therefore airow shall not be obstructed at any time. GDH units should be installed so that the
damper blades sit at least two times the width of the unit away from a blower or change in direction of ductwork on
the upstream side of the unit. Bends in the ductwork should not be placed until 920mm on the downstream side of the
dampers. Approval should be sought by Seeley for any installation encroaching on these limits. No modications shall
be made to the unit.
1.1.3 Combustibles
The heater should not be installed in contact with combustible materials. Radiant heat from the unit must also be
considered.
SAFETY

4 |
1.1.4 Wiring Electrical
Connections must be in accordance with all relevant Australian Standards and applicable State regulations.
1.1.5 Occupational Health and Safety
Only safe working practices shall be employed when working on gas installations. The process of installing gas
appliances shall take into consideration relevant OH&S requirements. There requirements pertain to all aspects
of access, installation, operation and maintenance. Persons installing gas appliances shall be aware of their
responsibilities and qualied in accordance with local OH&S requirements. Precautions shall be taken to avoid any
electrical hazards present in the gas installation.
1.1.6 Gas Piping
Gas piping should be sized adequately, located, supported and protected in accordance with the Installation Standard
AS/NZS 5601.
1.1.7 Commissioning, Recommissioning and Decommissioning
Every gas installation shall be commissioned according to the instructions in Section 4 of this Manual prior to use to
ensure safe start and operation of the unit and shall include checks of safety and operating control. All GDH units are
type B units and will require a type B certication before they can be operated.
Following maintenance work on any part of the unit, the a󰀨ected part of the installation shall be re-commissioned by
checking to ensure safe start-up and operation.
After a maintenance shutdown, isolation of the unit or interruption to the gas or electrical supply an appropriately
qualied person shall conduct start up checks to conrm safe operation.
When a unit is being decommissioned it shall be physically disconnected from the gas supply, purged and sealed.
Where possible components should be recycled, apart from the gas train and valves which should be disposed of in
accordance with government regulations.
1.1.8 Operational Safety
AIRA GDH Heaters must not be operated until the unit has been commissioned by qualied persons. The unit should
not be operated if any safeguards, panels or controls have been removed, damaged or bi-passed.
If the unit is not operating as intended turn o󰀨 the unit at the rotary switch/BMS and then isolate the power and gas
supply. The unit should remain isolated until a qualied service technician has inspected the unit and resolved any
issues.
1.1.9 Gas Compliance
Aira GDH heaters are NOT Type A certied. Type B certication is required. AS/NZS 5601.1 states that the
requirements of the standard are to be used in conjunction with, but do not take precedence over, statutory
requirements that may apply in any area. Refer to your local state regulator for certication requirements. Where no
requirement is given, good practice shall apply.
SAFETY

AIRA DIRECT FIRED GAS HEATING INSTALL OPERATION MAINTENANCE MANUAL |5
1.1.10 Safety Points to Consider
• What is the best and safest access to the roof and/or work areas?
• If a worker is alone, who knows they are there and if they get into di󰀩culty, how can they summon help? (Call
someone on the ground? Mobile phone? etc.)
• Has the roof section or structure been assessed to ensure that it can withstand the load of the appliance and
workers.
• Does the worker have appropriate foot wear?
• Are all power cables / extension leads safe and appropriately rated?
• Are all ladders, tools and equipment suitable in good condition?
• Where ladders are to be used, is there a rm, stable base for them to stand on? Can they be tied or secured in
some way at the top? Is the top of the ladder clear of electricity supply cables?
• Is there a roof anchor to attach a harness and lanyard to? If so, instruction should be issued for the use of an
approved harness or only suitably trained people used.
• Are all tools and materials being used, prevented from slipping and falling onto a person at ground level? Is the
area below the work area suitably protected to prevent persons walking in this area?
• Does the work schedule take into account weather conditions, allowing for work to be suspended in high winds,
thunder storms/lightning or other types of weather giving wet, slippery surfaces?
• Is there an on-going safety check system of harnesses, ropes, ladders and access/lifting equipment and where
they exist on roofs, anchor points before the commencement of work?
• Is there a system which prevents employees from working on roofs if they are unwell or under the inuence of
drugs or alcohol?
• Are there any special conditions to consider i.e. excessive roof pitch, limited ground area, fragile roof, electrical
power lines?
• Is the person conducting the installation and maintenance appropriately qualied and familiar with local authority
and AS/NZS5601
SAFETY

6 |
2.1 UNIT OVERVIEW
ARIA GDH units are direct gas red heaters. The standard control system is a standalone control system utilising a
room thermostat to control heat demand from the GDH. An optional is also available congured for integration with
Building Management Systems (BMS). Each GDH unit is provided with a comprehensive control and wiring information
package.
Gas rate modulation is provided to maintain a more consistent room temperature. Once the room set temperature
is reached the unit will cease heating. Consequently, as the room temperature falls below the set point the unit will
automatically resume heating.
GDH units require integration with a fan or blower to operate. The size of the unit will determine the airow required.
Seeley International can supply a blower/evaporative cooler to suit requirement of the GDH and provide integrated
controls. If using a 3rd party blower or cooler it is the installers responsibility to ensure that there is su󰀩cient air ow
is provided across the unit and that the blower/fan is compatible with the GDH controls to ensure safe and compliant
operation.
Units are not ued, and combustion gases will enter the space being heated. It is the installers responsibility to ensure
that there is su󰀩cient relief for the gases to escape the heated area. The area being heated should not be sealed.
Commissioning of GDH Type B units will require independent type B certication to local legislation.
2.2 EQUIPMENT RECEIPT
Inspect the unit for any damage caused in transit. Any such damage must be immediately reported to the shipper of the
goods.
The unit has been factory tested to check for correct operation of all components. If any part is obviously missing or
damaged, notify the supplier immediately.
Check the appliance to ensure that the GDH unit that has been supplied will operate with the available gas supply, i.e.
Natural or LPG gas.
2.3 FACTORY UNIT TEST
All AIRA GDH units are given a factory unit test which covers the function test and checks of the safety system
including;
• Gas ignition and ame detection
• Gas valve modulation
• Operation of the High Limit Safety Switch
• Functional test for all units
GENERAL INFORMATION

AIRA DIRECT FIRED GAS HEATING INSTALL OPERATION MAINTENANCE MANUAL |7
2.4 TECHNICAL SPECIFICATION
2.4.1 Unit and Component Identication
GENERAL INFORMATION
2.4.2 Construction
• The main paneling and weatherproof casing enclosing the gas train and controls are made from galvanized steel.
• Duct mate is connected to both ends of the unit for connections to ductwork
• The burners are aluminium with a stainless steel ba󰀪e and end plates.
2.4.3 Blower/Fan
• GDH units require a fan or blower to operate. GDH units do not have an attached fan which must be ordered
separately.
• GDH units are compatible with AIRA AL and Braemar RPB evaporative coolers creating a combined heating and
cooling system.
2.4.4 Dampers
• All units are supplied with galvanized steel dampeners which are sized based on the airow across the burner and
the desired temperature rise.
• Adjustable damper models are available by special request allowing for additional airow when combined with a 2
speed evaporative cooler.
2.4.5 Electrical Control
• All units are equipped with an electrical control box which controls the Gas Pilot, Main Valve, Modulating Valve and
blower operation (when installed).
• All units are tted with High Limit Safety Switches which are to be installed into the ductwork once the unit is
installed. The switch is to be set to 80°C.
• Units are tted with a ame controller which runs a pre-purge cycle. This will activate the connected fan/blower to
run for 30 seconds before a 5 second ignition sequence begins.
Specication GDH790 GDH1055 GDH1585 GDH2110 GDH2500
Power Supply Voltage/Phase/HZ 240/1/50
(415/3/50 Blower)
240/1/50
(415/3/50 Blower)
240/1/50
(415/3/50 Blower)
240/1/50
(415/3/50 Blower)
240/1/50
(415/3/50 Blower)
Power
Consumption Max Power 1.15 1.15 1.15 1.15 1.15
Controller
Type (standard) Rotary Switch Rotary Switch Rotary Switch Rotary Switch Rotary Switch
Type (Optional) BMS BMS BMS BMS BMS
Voltage/Phase/HZ
BMS
(Customer
supplied)
BMS
(Customer
supplied)
BMS
(Customer
supplied)
BMS
(Customer
supplied)
BMS
(Customer
supplied)
Gas Supply
Connecton (mm) 40 40 40 40 40
Input (MJ/h) 790 1055 1585 2110 2500
Output (kW) 220 293 440 586 694
Airow L/s for a 35/42/55 °C
Temperature Rise 4790/3391/3048 6379/5316/4059 9580/7983/6096 12759/10632/8119 15110/12592/9615
Cooler Match
AIRA AL 25 25 30 30 36
Braemar RPB (Upon
Request) 700 900 1300 1400 N/A
Unit Size
Unit Weight 115 120 145 267 272
Dimensions LxWxH
(mm) 1500x990x990 1500x990x990 1500x1150x1150 1500x1400x1400 1500x1400x1400
Shipping
Shipping Weights 150 155 180 297 302
Shipping
Dimensions LxWxH
(mm)
1700x1650x1200 1700x1650x1200 1700x1650x1400x 2300x2300x1600 2300x2300x1600
Table 1: GDH Technical Data

8 |
3.0 INSTALLATION INFORMATION
The supplied units are to be installed in accordance to this manual, relevant local standards, acts and regulations.
GDH units are type B certied and will require a type B certier to sign o󰀨 the installation of the unit prior to use. All
labeling required by AS5601.1, AS3814 and local regulations and requirements must be on display including the
combustion product in accordance with section 5.7.7.1 of AS AS3814.
INSTALLATION INFORMATION
3.1 MODEL VARIATIONS AND DIMENSIONS
Before installation of a direct red heated the installer must notify the local gas supply authority and provide the
following information
1. Burner Data
2. Purge and critical time calculations
3. Wiring Diagram
4. Valve Train Layout.
This information can be requested from Seeley international when ordering the unit.
Isolation of the gas and electrical supplies to the units shall be accessible and identiable at all times. GDH units must
be supplied with fresh air only (Return air is not optional). The fresh air intake is to be clear of ues, exhaust outlets ect.
Gas train schematic and wiring diagram have a location to ll in site specic data (address and contact).
Unit 790 1055 1585 2110 2500
A1500 1500 1500 1500 1500
B990 990 1150 1400 1400
C310 310 310 310 310
Figure 1: AS3814 Section 5.7.7.1
Table 2: Dimensions

AIRA DIRECT FIRED GAS HEATING INSTALL OPERATION MAINTENANCE MANUAL |9
INSTALLATION INFORMATION
Figure 2: GDH Units

10 |
INSTALLATION INFORMATION
3.2 INSTALLATION
The following recommendations are not intended to supplant or take precedence over relevant o󰀩cial regulations. AIRA
GDH units are designed essentially as a roof top or external ground mount unit.
3.2.1 Location
This equipment is not designed for long and complex air distribution ductwork and as such the unit should be located
as close as practicable to the points of air distribution. GDH units. Depending on large volumes of 100% fresh air, care
must be taken to locate the unit clear of kitchen exhausts, heavy vehicle tra󰀩c, industrial fume discharge etc. that
may allow odour or fume laden air to be drawn into the unit. The prime requisites for the correct location of a unit is an
unrestricted supply of clean fresh air. The unit will push combustion gases from the burner into the heated area where
adequate relief air must be supplied to prevent the buildup of harmful gases. Failure to do so may result in fatalities.
When selecting a location for the GDH unit the following shall be considered.
1. Will the unit be suitably protected from the e󰀨ects of corrosion and/ or dust laden environments and any likelihood
of physical damage?
2. Can qualied personal perform functional adjustments and maintenance on the unit?
3. Does the chosen location prevent a hazard to the building or structure or to the contents of the building?
4. How to minimize the risks associated with storage, use or release of hazardous or ammable substances in the
vicinity of the unit?
5. How to minimize risk of harm to persons?
6. Will the noise of the unit operating a󰀨ect persons nearby? Units should be located so that quiet areas such as
meetings rooms, o󰀩ces etc. are not a󰀨ected for both the premises that the unit is being installed and adjoining
properties.
7. A structural engineer is to be engaged to prove that the supporting structure is suitable for a fully laden unit.
8. Ensure any skylights within 3m of the units have adequate fall protection installed
3.2.2 Clearance Around Unit
1000mm is the minimum recommended clearance around all sides for service access
Figure 3: Unit Clearance

AIRA DIRECT FIRED GAS HEATING INSTALL OPERATION MAINTENANCE MANUAL |11
INSTALLATION INFORMATION
3.2.4 Lifting
GDH units may be lifted by passing straps or chains through the centre of the unit or by slinging underneath. Special
care should be taken to avoid damaging gas connection, dampers and control box housing.
3.2.3 Weight And Location
For roof mounting, the building’s roof must be adequately designed to support the unit weight and any service
personnel. If in doubt a suitably qualied Civil or Structural Engineer should be engaged to conduct an assessment.
The below gures and tables list the weights of the units.
MODEL WEIGHT
GDH790 115kg
GDH1055 120kg
GDH1585 145kg
GDH2110 267kg
GDH2500 272kg
3.2.5 Positioning and Securing
GDH units are to be positioned so that the centre of the damper is 2 times the width of the duct from a bend or air
source upstream and 915mm from a bend downstream as shown belo
The GDH unit shall be supported to minimize deection of the ductwork. Supports are the responsibility of the installer
and should be done with reference to AS4254- Ductwork for air handling systems in buildings.
3.2.6 Duct Connections
The inlet and outlet of the unit is provided with a Ductmate® ductwork connection. An inspection and service panel
is located above and below the duct connection ange. Duct connections shall be done in accordance with relevant
standard.
Table 3: Weight
Figure 4: GDH Positioning

12 |
INSTALLATION INFORMATION
3.3 ELECTRICAL CONNECTIONS
3.3.1 Electrial Supply
All electrical connections are to be as per AS3000. All electrical work shall be performed by a registered electrical
contractor. AIRA GDH units are provided with an electrical wiring diagram with di󰀨erent diagrams for di󰀨erent control
setups.
Electrical connections are to be made in the control box.
When wiring the unit:
• DO NOT run cables or conduit across the heater
• DO NOT wire directly into the control box except for control wires as per the wiring diagram
• DO NOT modify the control box wiring a󰀨ecting the safety systems
• DO NOT bypass safety systems
3.3.2 User Control Conguration Optionsit
There are 2 primary control options for AIRA GDH units, Rotary switch and BMS. Units are specied with either a rotary
switch or capability to be wired for BMS interface. Rotary switch units have a Siemens room thermostat supplied
OFF UNIT IF OFF
FAN LOW VENTILATION ONLY, FAN ON LOW SPEED
FAN HIGH VENTILATION ONLY, FAN ON HIGH SPEED
LOW COOL FAN ON LOW, WATER SUPPLIED TO COOLING PADS (IF FITTED)
HIGH COOL FAN ON HIGH, WATER SUPPLIED TO COOLING PADS (IF FITTED)
HEAT FAN ON HIGH, GAS SUPPLIED TO UNIT IF THERMOSTAT IS SET ABOVE CURRENT
ROOM TEMPERATURE
Figure 5: Thermostat Figure 6: Wall Switch
Table 4: User Controls

AIRA DIRECT FIRED GAS HEATING INSTALL OPERATION MAINTENANCE MANUAL |13
INSTALLATION INFORMATION
3.3.3 Blower / Fan Setup
GDH units are supplied with a pressure switch that only allows gas to ow once airow is detected. The pressure
switch is to be set during the commissioning of the unit.
Blowers/fan shall be installed in a location in accordance with 3.2.7 Positioning and Securing.
3.4 GAS CONNECTIONS
3.4.1 Gas Supply
This unit must be installed in accordance with AS/NZS 5601.1. Before connecting the unit to the gas line. The gas line
must be fully purged and checked to ensure that they are free of dirt and foreign objects.
The gas supply pipe must be of adequate size to the heater and all gas appliances onsite. The screwed inlet
connection to the heater “Must Not” be used as an indication of the gas line’s sizing required. Units are tted with a
40mm Gas valve this doesn’t indicate the line diameter size. Gas lines must be sized to consider the length of the pipe
and any other attached appliances to ensure adequate ow and pressure are supplied to the unit. Gas line size will be
dependent upon ow rate required and line length. Refer to AS 5601.1 Appendix F for sizing of supply gas line.
The gas supply line must bear no load and be adequately supported and align with the units gas train. Do not
overtighten gas valve connection. A cracked body on inlet side of gas valve will not be covered by warranty. Check all
gas connections for leaks using soap solution or suitable gas leak detection uid.
Gas pressure for both Natural Gas and LPG is listed below in Table 5. If the pressure is greater than 7kPA an over
pressure shut o󰀨 regulator is required.
GAS PRESSURE NG LPG
Maximum kPa 7.0 7.0
Minimum kPa 1.12 1.12
If the inlet test pressure is not at least 1.12kPa for Natural Gas the following may have occurred;
• Gas pipe to the unit may be undersized and/or restricted
• The Gas meter may be undersized
• The Gas regulator may be set too low
If you suspect that the gas pressure is too low contact the Gas Supply authority
DO NOT Attempt to adjust the main supply regulator where the gas enters the premises
3.4.2 LPG
Adequate sizing and the number of LPG bottles is of high importance when considering an LPG unit. Pressures can
dramatically drop as the bottles become empty. This can a󰀨ect the combustion process within the unit causing light
back and poor combustion leading to excessive emissions.
3.4.3 Gas Train Information
The Gas Train as pictured in Figure 7 is installed as part of the unit. It is the responsibility of the installer to provide the
pipework to the gas train and ensure that the supply pipework is of adequate size and pressure.
1. When connecting the gas pipe, there may be an accumulation of condensates and other deposits in the gas pipe.
These must be cleared before connecting the gas pipe to the unit.
2. Purge all air from the gas pipe and check for leaks using a soap and water solution or approved leak test method.
The connections along the gas train should also be checked to ensure that there was no damage caused during
transportation and installation of the unit.
Note: All gas operating pressure tests must be completed with all gas appliances operating at full capacity.
Table 5: Gas Pressure

14 |
INSTALLATION INFORMATION
3.4.4 Gas Valve
The double gas valve supplied with the GDH unit is the same for both LPG and natural gas. The gas valve has a 40mm
inlet.
Pilot pressure adjustmentPilot pressure adjustment
Figure 7: Gas Train
Figure 8: Gas Valve

AIRA DIRECT FIRED GAS HEATING INSTALL OPERATION MAINTENANCE MANUAL |15
INSTALLATION INFORMATION
3.4.5 Standard Operating Pressure of the Gas Valve
Unit Gas Type High Pressure (kPA) Low Pressure (kPA)
GDH790
Natural Gas 0.875 0.5
LPG 0.35 0.25
GDH1055
Natural Gas 0.875 0.5
LPG 0.35 0.25
GDH1585
Natural Gas 0.875 0.5
LPG 0.35 0.25
GDH2110
Natural Gas 0.875 0.5
LPG 0.35 0.25
GDH2500
Natural Gas 0.78 0.5
LPG 0.3 0.23
Note: Gas pressure outside of the specied range are to be conrmed with Seeley International. Gas pressures
will require adjustment on site to ensure that the combustion gases are below the allowable limits.
3.4.6 Setting Gas Valve Pressure
The regulated valve pressure is to be set based of the ranges in Table 6.
To set the regulated pressure follow the steps below.
1. Connect a manometer to the double gas valve pressure test point.
2. Measure the incoming gas pressure to ensure that it less than 7kPa. If found to be greater than 7kpA the gas valve
may be in a locked state. A pressure regulator will need to be installed upstream of the gas valve to provide the
correct gas supply pressure in accordance with Table 3. If the gas valve is a locked state the line will need to be
bled between the regulator and the valve to relieve excess pressure.
3. Ensure gas pressure test point has been closed.
4. Check gas train for leaks.
3.4.7 Setting the Modulating Valve Motor
The ball valve to motor alignment and limits are factory preset. Site gas pressure may di󰀨er to factory settings therefore
requiring modulating motor limit adjustment.
Aligning the Motor and Valve Shaft
1. Open gas valve fully with motor removed. (This is indicated by the valve shaft at facing outwards) Removal of the
adaptor shaft may be required to identify the shaft at.
2. Reinstall adaptor shaft ensuring grub screws are tight.
3. Set modulating motor to 90° and install over the adaptor shaft. Tighten no.9 SHCS in Figure 19: Modulating Motor
onto Adaptor Shaft.
Setting Modulating Motor
The minimum low re rate must not be less than 59% of full re rate.
To set the re rate follow the steps below;
1. Engage the slider (5) to disengage the gear train, set the modulating ball valve to 100% open
2. Check the test point pressure against the full gas setting
3. Low re may be adjusted by limiting the travel of the modulating valve, utilizing adjusting screw (11) to ensure the
gas cuts o󰀨 before the rate is reduced too far
Table 6: Gas Pressure

16 |
Correct adjustment MUST be made, too low gas pressure will result in a “light-back” condition, damaging the
burner’s ports and result in a buildup of soot and replacement of burners.
AMI011-B
Figure 9: Modulating Motor
INSTALLATION INFORMATION
1. BASE PLATE AND MOUNTING
2. ROTATIONAL ANGLE SCALES
0º...90º / 90º...0º
3. DIL SWITCHES FOR
- SELF ADAPTION
- ROTATIONAL MOVEMENT DIRECTION
- INVERTED OR NON INVERTED OUTPUT
VOLTAGE OPERATING FUNCTION
4. COVER FOR DIL SWITCHES
5. CONNECTING CABLE FOR POWER, CONTROL SIGNAL,
AND POSITION INDICATION
6. SLIDER TO DISENGAGE THE GEAR TRAIN
7. COUPLING BUSHING
8. CENTERING ELEMENT FOR GLB...1E
(SHAFT DIAMETER 8....10MM)
9. POSITION INDICATOR
10. ADJUSTMENT LEVER WITH SHAFT FASTENING SCREW
11. ADJUSTING SCREW FOR ROTATIONAL ANGLE
LIMITATION
12. MOUNTING BRACKET

AIRA DIRECT FIRED GAS HEATING INSTALL OPERATION MAINTENANCE MANUAL |17
INSTALLATION INFORMATION
3.4.8 Pilot Injector Setup
The pilot mounts to a bracket attached to the side of the burner. The burner with the pilot attached should be in the
center of the burner chamber.
The Pilot Ignitor, Spark Ignitor and Flame Rod comes as an assembly. Care must be taken when working on the pilot
system not to damage the aluminum gas hard line. Natural gas and LPG units have di󰀨erent assembly
DO NOT modify the position of the pilot in relation to the burner. Altering the pilot can cause explosive ignition. Ensure
that the pilot is secured in position.
Figure 10: Pilot Injector

18 |
INSTALLATION INFORMATION
3.4.9 Leaving Air Temperature Sensor
GDH units have a leaving air temperature that comes wound up inside the control box. It is the installers responsibility
to run the leaving air temperature sensor 1000mm downstream of the burner.
Figure 11: Air Temperature Sensor