COMBAT CTU-90 Guide

WARNING
FOR YOUR SAFETY
If you smell gas:
1. Open windows.
2. DO NOT try to light any appliance.
3. DO NOT use electrical switches.
4. DO NOT use any telephone in
your building.
5. Extinguish any open flame.
6. Leave the building.
7. Immediately call your local gas
supplier after leaving the building.
Follow the gas supplier’s
instructions.
8. If you cannot reach your gas
supplier, call the Fire Department.
Fire Hazard
Keep all flammable objects, liquids and
vapours the minimum required
clearances to combustibles away from
heater.
Some objects will catch fire or explode
when placed close to heater.
Failure to follow these instructions can
result in death, injury or property
damage.
WARNING
Installation must be done by a registered installer/
contractor qualified in the installation and service
of gas-fired heating equipment or your gas supplier.
Improper installation, adjustment, alteration, service
or maintenance can result in death, injury or
property damage. Read the installation, operation
and service manual thoroughly before installing or
servicing this equipment.
Installer
Please take the time to read and understand
these instructions prior to any installation.
Installer must give a copy of this manual to the owner.
Owner
Keep this manual in a safe place in order to provide
your service technician with necessary information.
©2017 Combat HVAC Limited
Combat HVAC Limited
Unit 20 , Red Mill Trading Estate
Rigby Street,Wednesbury
West Midlands, WS10 0NP
Telephone: [phone]
Fax: [phone]
Service Telephone: [phone]
Service Fax: [phone]
E-mail: uksales@ combat.co.uk
E-mail: expor [e-mail]
www . combat.co.uk
Combat®
Installation, Commissioning,
Operation & Service Manual
Model CTU
75 to 115
P/N X408UK Orig. 09/14
Tubular Unit Heaters

© 2017Combat HVAC Limited
All rights reserved. Nopartof this work covered bythe copyrights herein maybereproduced
or copied in any form or by any means - graphic, electronic, or mechanical, including
photocopying, recording, taping or information storage and retrieval systems - without
the written permission of Combat HVAC Limited.
Printed in U.K.
TABLE OF CONTENTS
SECTION 1: Heater Safety ...................................................... 2
1.1 Manpower Requirements ............................................. 2
1.2 Safety Labels and Their Placement ............................. 2
SECTION 2: Installer Responsibility ..................................... 4
2.1 Laminated Wall Plate ................................................... 4
2.2 Corrosive Chemicals .................................................... 4
2.3 National Standards and Applicable Regulations.......... 4
SECTION 3: Clearances to Combustibles............................. 5
3.1 Required Clearances to Combustibles......................... 5
SECTION 4: Critical Considerations ..................................... 7
4.1 Ventilation .................................................................... 7
4.2 Gas Supply .................................................................. 7
4.3 Electrical Supply .......................................................... 7
4.4 Flue.............................................................................. 7
SECTION 5: Specifications .................................................... 8
5.1 CTUA .......................................................................... 8
5.2 CTUB, CTUC and CTUD ............................................. 9
5.3 General Technical Data Table ................................... 10
5.4 Technical Data Table .................................................. 11
SECTION 6: Heater Installation............................................ 12
6.1 General ...................................................................... 12
6.2 Basic Information....................................................... 12
6.3 Location and Suspension .......................................... 12
6.4 Handling .................................................................... 12
6.5 Suspension and Shelf Mounting................................ 12
SECTION 7: Flue Installation ............................................... 14
7. 1 F l ue Installation .......................................................... 14
7.2 Type C12, C32 & C62 Appliance..................................... 14
7.3 Type B22 Appliance ..................................................... 14
SECTION 8: Air Supply ......................................................... 16
8.1 Room Sealed Installation ........................................... 16
8.2 Open Flued Installation .............................................. 16
8.3 Building Ventilation .................................................... 16
8.4 Isolated Equipment Rooms........................................ 16
SECTION 9: Optional Heater Configurations...................... 17
9.1 Distribution Duct Work for CTUB, CTUC and CTUD
Heaters ...................................................................... 17
SECTION 10: Gas Pipe Work ................................................ 18
10.1 Connections ............................................................. 18
SECTION 11: Wiringand Electrical Information ................. 20
11.1 Electrical Supply ....................................................... 20
11.2 Remote Controls ....................................................... 20
11.3 CTUA Wiring Diagram (Models 75-115).................... 21
11.4 CTUB/C Wiring Diagram (Models 75-115)................ 22
11.5 CTUD Wiring Diagram (Models 75-115) ................... 23
11.6 CTUD External Motor Alternative Wiring & Optional
Thermostat/Time Switch............................................ 24
SECTION 12: Commissioning.............................................. 25
12.1 Pre-Commission Checks.......................................... 25
12.2 Gas Supply .............................................................. 25
12.3 Mechanical Checks .................................................. 25
12.4 Begin Commissioning .............................................. 26
12.5 Combustion Testing..................................................27
12.6 Turning Off the Heater..............................................27
12.7 External Controls......................................................28
12.8 Complete the Commissioning ..................................28
12.9 Instruction to the User..............................................28
SECTION 13: User Instructions............................................29
13.1 User Instructions ......................................................29
13.2 Heater Operation......................................................29
13.3 Common User Controls............................................30
13.4 Lighting Instructions .................................................30
13.5 Simple Fault Finding.................................................30
SECTION 14: Servicing.........................................................31
14.1 Servicing Instructions...............................................31
14.2 Burner Maintenance.................................................31
14.3 Fan/Motor Assembly Maintenance ...........................31
14.4 Heat Exchanger Maintenance ..................................32
14.5 Gas Control Valve Maintenance ...............................32
14.6 Flue Fan ...................................................................32
14.7 Maintenance Checklist .............................................32
SECTION 15: Conversion Between Gases ..........................34
15.1 General ....................................................................34
15.2 Burner Conversion ...................................................34
15.3 Gas Valves ...............................................................34
SECTION 16: Troubleshooting.............................................35
16.1 General ....................................................................36
16.2 Troubleshooting For Automatic Ignition Burner
Systems ...................................................................37
16.3 Troubleshooting for Flame Supervision System .......38
16.4 Troubleshooting for Solenoid Valves ........................38
SECTION 17: Removal and Replacement Parts..................39
17.1 Gas Valve..................................................................39
17.2 Burner Compartment................................................40
17.3 Ignition Electrode and Flame Probe..........................42
17.4 Flue Fan....................................................................43
17.5 Pressure Switch ........................................................44
17.6 Ignition Control..........................................................45
17.7 CTUA Axial Fan/Guard/Motor Assembly...................45
17.8 CTUB & CTUC Centrifugal Fan/Guard/Motor
Assembly ..................................................................45
17.9 Fan Data ...................................................................46

TABLE OF FIGURES
Figure 1: Side and Back Panel Label Placement...................... 2
Figure 2: Side Panel Label Placement...................................... 3
Figure 3: Installation Clearances and Clearances to
Combustibles ............................................................. 6
Figure 4: Suspension Methods ............................................... 13
Figure 5: Flue and Roof Detail ................................................ 14
Figure 6: Vertical and Horizontal Flue Termination -
Type B22 Appliance .................................................. 15
Figure 7: Vertical and Horizontal Flue Termination -
Type C12 C32 & C62 Appliances ................................. 15
Figure 8: Heaters Installed in Isolated Equipment Rooms ...... 16
Figure 9: Ducting..................................................................... 17
Figure 10: Gas Connection with Stainless Steel Flex
Connector .............................................................. 19
Figure 11: Sequence of Operation Chart ................................ 26
Figure 12: Gas Valve for Heater (Models 75 - 115) ................. 27
Figure 13: Heater Operating Sequence .................................. 29
Figure 14: Centrifugal Fan Orientation .................................... 46

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Product Approval
ROBERTS GORDON® appliances have been tested and CE certified as complyin with the essential
requirements of the Gas Appliance Directive, the Low Volta e Directive, the Electroma netic
Compatibility Directive and the Machinery Directive for use on natural as and LPG when installed,
commissioned and maintained in accordance with these instructions.
These instructions refer to appliances desi ned to operate in the European Union.
Appliances desi ned for other countries (Non-European Union) are available on request.
This appliance must be installed in accordance with the local and national codes in force and used
only in a sufficiently ventilated space, as specified in these instructions.
Before installation, check that the local as distribution systems, nature of as and pressure, and
adjustment of the appliance are compatible.

COMBAT®CTU UNIT HEATERS INSTALLATION OPERATION AND SERVICE MANUAL
2 of 46
SECTION 1: HEATER SAFETY
Yo ur Safety is Important to Us!
This symbol is used throughout the
manual to notify youof possible fire,
electrical or burn hazards. Please pay
special attention when reading and
following the warnings in these sections.
Installation, service and annual inspection of heater
must be done by a registered installer/contractor
qualified in the installation and service of gas-fired
heating equipment.
Read this manual carefully before installation,
operation, or service of this equipment.
This heater is designed for heating non-domestic
indoor spaces. Do not install in domestic spaces.
These instructions, the layout drawing, local codes
and applicable standards that apply to gas piping,
electrical wiring, venting, etc. must be thoroughly
understood before proceeding with the installation.
Protective gear is to be worn during installation,
operation and service. Thin sheet metal parts of the
heater and the various venting components have
sharp edges. To prevent injury, the use of work
gloves is recommended.
Before installation, check that the local distribution
conditions, nature of gas and pressure, and
adjustment of the appliance are compatible.
The heater must be applied and operated under the
general concepts of reasonable use.
This appliance isnot intended for use by persons
(including children) with reduced physical, sensory
or mental capabilities, orlack ofexperience and
knowledge, unless they have been given
supervision orinstruction concerning use of the
appliance by a person responsible for their safety.
Children should besupervised to ensure that they
do no play with the appliance.
For additional copies of the Installation, Operation
and Service Manual, please contact Combat HVAC
Limited.
1.1 Manpower Requirements
To prevent personal injury and damage to the
heater, two persons will be required for installation.
1.2 Safety Labels andTheir Placement
Product safety signs or labels should be replaced by
the product user when they are no longer legible.
Contact Combat for obtaining replacement signs or
labels. See Page 2, Figure 1 through Page 3,
Figure 2.
Figure 1: Side and Back Panel Label Placement
Description Part Number
Logo Label 91040030
Lockout Reset Label 91038303
Address Label 91040006
Rating Plate Label 91040001
Email: [email protected]
Email: [email protected]
Combat HVAC Limited
Unit 20 Red Mill Trading Estate
Rigby Street, Wednesbury
West, Midlands, WS10 0NP
www.combat.co.uk
Combat HVAC Limited
Email: [email protected]
Email: [email protected]
Combat HVAC Limited
Unit 20 Red Mill Trading Estate
Rigby Street, Wednesbury
West, Midlands, WS10 0NP
www.combat.co.uk
Combat HVAC Limited

SECTION 1: HEATER SAFETY
3 of 46
Figure 2: Side Panel Label Placement
Description Part Number
Lighting Instruction Label 91040002
Remote Reset Label 91040019
Terminal Label 91130301
Wiring Diagram Label 75-115 91040004

COMBAT®CTU UNIT HEATERS INSTALLATION OPERATION AND SERVICE MANUAL
SECTION 2: INSTALLER RESPONSIBILITY
•To install the heater, as well asthe gas and elec-
trical supplies, inaccordance with applicable
specifications and regulations. Combat
recommends the installer contact a local
authority, building inspector or insurance
company for guidance.
•Touse the information given inthemanual
together with the local and national regulations
to perform the installation.
•To install the heater in accordance with the
clearances to combustibles ofthis heater.
•To apply allneeded materials not supplied
as standard equipment.
•To plan location of supports, flues and air intakes.
•To provide access to burners for servicing.
•To provide the owner with a copy ofthis
installation, commissioning, operation and
service manual.
•To never use heater as supportfor ladder or
other access equipment and never hang or
suspend anything from heater.
•To ensure that there is sufficient ventilation in the
area to comply with the requirements of
all relevant local and national regulations.
•To safely and adequately install heater using
materials with a minimal working load of 33 kg.
•To ensure the heater is placed in anapproved
application.
2.1 Laminated Wall Plate
Alaminated wall plate is available for the heater as a
permanent reminder of the safety instructions and
the importance of the required clearances to
combustibles. Affix theplate by peeling off the
backing of the adhesivestrips on the rear surface
and position the plate on a wall near the heater (e.g.
thermostat or Combat®Controller).
Acopy of the wall plate (P/N 91040028) isillustrated
on the back cover.Knowyour model number and
installed configuration. Model number and installed
configuration are found on the heater and in the
Installation, Operation and Service Manual.
4 of 46
2.2 Corrosive Chemicals
Combat cannot be responsible for ensuringthat all
appropriate safety measures are undertaken prior to
installation; this is entirely the responsibility of the
installer. Itisessential that the contractor, the sub-
contractor, or the owner identifies the presence of
combustible materials, corrosive chemicals or
halogenated hydrocarbons* anywhere in the
premises.
* Halogenated Hydrocarbons are a family of chemical
compounds characterized by the presence of halogen
elements (fluorine, chlorine, bromine, etc.). These com-
pounds are frequently usedinrefrigerants, cleaning
agents, solvents, etc. Ifthese compounds enter the air
supply of the burner,the lifespan of the heater compo-
nents will be greatly reduced. Warranty will be invalid if
the heater isexposed to halogenated hydrocarbons.
2.3 National Standards and Applicable
Regulations
All appliances must be installed in accordance with
the latest revision of applicable standards and local
and national regulations. This refers also to the
electric, gas and venting installation. Note:
Additional standards for installations inpublic
garages, aircraft hangars, etc. may be applicable.
CAUTION
Product Damage Hazard
Do not use heater in area containing
corrosive chemicals.
Refer to appropriate Material Safety Data
Sheets (MSDS).
Failure to follow these instructions can result
in product damage.