Roberts Gorden CTCU, CTCU 11, CTCU 15, CTCU 27, CTCU 22 User Manual

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. Leave the building.

6. Immediately call your local gas
supplier after leaving the building.
Follow the gas suppliers
instructions.

7. If you cannot reach your gas
supplier, call the Fire Department.

WARNING

®

C mbat

Compact Tubular Unit Heaters

Installation, Commissioning,

Operation & Service Manual

Models CTCU 7

CTCU 11
CTCU 15

CTCU 22

Fire Hazard

Do not store or use petrol or other
flammable vapours and liquids in the
vicinity of this or any other appliance.

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

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.

Installation must be done by a registered installer/
contractor qualified in the installation and service
of gas-fired heating equipment or your gas supplier.

CTCU 27
CTCU 32

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 serviceman with necessary information.

Quality in Any Language™

© Copyright 2006 Roberts-Gordon, LLC

Roberts-Gordon Europe Limited

Oxford Street
Bilston, West Midlands WV14 7EG UK
Telephone: [phone]
Fax: [phone]
Service Telephone: [phone]
Service Fax: [phone]
E-mail: [e-mail]
E-mail: [e-mail]

www.rg-inc.com

P/N 11110 0 UK Re v B 10 / 0 6

TABLE OF CONTENTS

SECTION 1: Heater Safety...................................................... 2

SECTION 2: Installer Responsibility .....................................2

2.1 Clearances to Combustibles ........................................ 2

2.2 Corrosive Chemicals....................................................2

2.3 National Standards and Applicable Codes .................. 2

SECTION 3: Critical Considerations .....................................3

3.1 Basic Information......................................................... 3

3.2 Location and Suspension ............................................3

3.3 Minimum Required Installation Clearances .................3

3.4 Clearances to Combustibles ........................................ 3

3.5 Ventilation .................................................................... 3

3.6 Gas Supply ..................................................................3

3.7 Electrical Supply .......................................................... 3

3.8 Flue..............................................................................3

SECTION 4: Specifications ....................................................5

4.1 CTCUA (All Models) ....................................................5

4.2 General Technical Data Table (All Models) ..................6

4.3 Technical Data Table (All Models)................................6

SECTION 5: Heater Installation.............................................. 7

5.1 General........................................................................ 7

5.2 Shelf Mounting and Suspension.................................. 7

5.3 Wall Mounting.............................................................. 7

SECTION 6: Flue Installation .................................................9

6.1 Changing Flue and Air Intake Orientation.................... 9

6.2 Flue Installation............................................................9

6.3 Type C

6.4 Type B

SECTION 7: Air Supply......................................................... 11

7.1 Room Sealed Installation ........................................... 11

7.2 Open Flued Installation .............................................. 11

7.3 Building Ventilation ..................................................... 11

SECTION 8: Gas Piping........................................................12

8.1 Connections............................................................... 12

SECTION 9: Wiring and Electrical Information................... 13

9.1 Electrical Supply ........................................................ 13

9.2 Remote Controls ........................................................ 13

9.3 CTCUA Wiring Diagram Models 7 - 32...................... 14

SECTION 10: Commissioning..............................................15

10.1 Pre-Commission Checks.......................................... 15

10.2 Begin Commissioning ..............................................15

10.3 Complete the Commissioning ..................................17

SECTION 11: User Instructions............................................ 18

11.1 User Instructions.......................................................18

11.2 Heater Operation ...................................................... 18

11.3 Common User Controls ............................................ 18

11.4 Lighting Instructions..................................................18

11.5 Simple Fault Finding................................................. 19

SECTION 12: Servicing.........................................................20

12.1 Servicing Instructions .............................................. 20

12.2 Burner Maintenance ................................................20

12.3 Fan/Motor Assembly Maintenance........................... 20

12.4 Heat Exchanger Maintenance..................................20

12.5 Gas Control Valve Maintenance...............................20

12.6 Flue Fan................................................................... 20

, C32 & C62 Appliance ...................................... 9

12

Appliance....................................................... 9

22

SECTION 13: Conversion Between Gases ..........................21

13.1 General ....................................................................21

13.2 Burner Conversion ...................................................21

13.3 Gas Valves ...............................................................21

SECTION 14: Troubleshooting .............................................22

14.1 General ....................................................................22

14.2 Troubleshooting For Automatic Ignition

Burner Systems .......................................................23

14.3 Troubleshooting for Flame Supervision System .......24

14.4 Troubleshooting for Solenoid Valves ........................25

14.5 Troubleshooting for Main Fan...................................25

SECTION 15: Removal and Replacement Parts..................26

15.1 Gas Valve .................................................................26

15.2 Burner Compartment ...............................................27

15.3 Ignition Electrode and Flame Probe.........................28

15.4 Flue Fan Vertical Installation ....................................29

15.5 Pressure Switch........................................................30

15.6 Ignition Control .........................................................31

15.7 CTCUA Axial Fan/Guard/Motor Assembly ...............31

15.8 Fan and Limit Thermostats ......................................31

© 2006

Roberts-Gordon, LLC

All rights reserved. No part of this work covered by the copyrights herein may be reproduced
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 Roberts-Gordon, LLC.

Printed in U.S.A.

TABLE OF FIGURES

Figure 1: Installation Clearances and Clearances to

Combustibles.............................................................. 4

Figure 2: Suspension Methods ................................................. 7

Figure 3: Shelf Mounting and Hanging Suspension.................. 8

Figure 4: Vertical Louvres (Optional) ........................................8

Figure 5: Flue and Roof Detail ..................................................9

Figure 6: Vertical and Horizontal Flue Termination -

Type B
Figure 7: Vertical and Horizontal Flue Termination -

Type C
Figure 8: Gas Connection with Stainless Steel

Flex Connector......................................................... 12

Figure 9: Automatic Burner Control Box Sequence ................16

Figure 10: Gas Valve for Heater Models 7 - 32 ....................... 16

Figure 11: Heater Operating Sequence...................................18

Appliance ................................................... 10

22

& C62 Appliances.................................. 10

12 C32

®

COMBAT

Compact Tubular Unit Heaters are high efficiency heaters and are listed on
the Enhanced Capital Allowance Scheme ’Energy Technology Product List’. The ETL
symbol is a UK registered certification mark of The Carbon Trust.

Product Approval

ROBERTS GORDON® appliances have been tested and CE certified as complying with the essential
requirements of the Gas Appliance Directive, the Low Voltage Directive, the Electromagnetic
Compatibility Directive and the Machinery Directive for use on natural gas and LPG when installed,
commissioned and maintained in accordance with these instructions.

These instructions refer to appliances designed to operate in the European Union.
Appliances designed 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 gas distribution systems, nature of gas and pressure, and

adjustment of the appliance are compatible.

1

COMBAT® CTCU UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

SECTION 1: HEATER SAFETY

Your Safety is Important to Us!
This symbol is used throughout the

clearances to combustibles. Affix the tag on a wall

near the heater.
manual to notify you of possible fire,
electrical or burn hazards. Please pay

2.2 Corrosive Chemicals

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

Do not use heater in an area containing corrosive
chemicals.

qualified in the installation and service of gas-fired
heating equipment.

Read this manual carefully before installation,
operation, or service of this equipment.

Corrosive chemicals will damage the burner and
heat exchanger parts.

Failure to follow these instructions can result in
property damage.

This heater is designed for heating non-residential
indoor spaces. Do not install in residential spaces.
These instructions, the layout drawing, local codes
and ordinances and applicable standards that apply
to gas piping, electrical wiring, venting, etc. must be
thoroughly understood before proceeding with the
installation.

Roberts-Gordon cannot be responsible for ensuring

that all appropriate safety measures are undertaken

prior to installation; this is entirely the responsibility

of the installer. It is essential that the contractor, the

sub-contractor, or the owner identifies the presence

of combustible materials, corrosive chemicals or

halogenated hydrocarbons* anywhere in the

SECTION 2: INSTALLER RESPONSIBILITY

• To install the heater, as well as the gas and elec­trical supplies, in accordance with applicable
specifications and codes. Roberts-Gordon
recommends the installer contact a local
building inspector, Fire Officer or insurance
company for guidance.

• To use the information given in the manual
together with the local and national codes to
perform the installation.

• To install the heater in accordance with the
clearances to combustibles of this heater.

• To furnish all needed materials not furnished
as standard equipment.

• To plan location of supports, flues and air

premises.

* Halogenated Hydrocarbons are a family of chemical
compounds characterized by the presence of halogen
elements (fluorine, chlorine, bromine, etc.). These
compounds are frequently used in refrigerants, cleaning
agents, solvents, etc. If these compounds enter the air
supply of the burner, the lifespan of the heater
components will be greatly reduced. Warranty will be
invalid if the heater is exposed to halogenated
hydrocarbons.

2.3 National Standards and Applicable Codes

All appliances must be installed in accordance with
the latest revision of applicable standards and local
and national codes. This refers also to the electric,
gas and venting installation. Note: Additional
standards for installations in public garages, aircraft
hangars, etc. may be applicable.

intakes.

• To provide access to burners for servicing.

• To provide the owner with a copy of this
Installation, Commissioning, Operation and
Service Manual.

• To never use heater as support for 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 codes.

2.1 Clearances to Combustibles

In all situations, clearances to combustibles must be
maintained. Caution must be used when running the
heater near combustible materials such as wood,
paper, rubber, etc. A wall tag is on the back cover of
this manual as a permanent reminder of the safety
instructions and the importance of the required

CAUTION

2

SECTION 3: CRITICAL CONSIDERATIONS

3.1 Basic Information

CTCU heaters have automatic ignition burners for
ON/OFF operation only.

3.2 Location and Suspension

All models:

• Must be installed indoors.

• Must be installed in a level position with horizon­tal or vertical discharge.

• May be mounted on a shelf of non-combustible
material. (See Page 5, Section 4 and Page 7,
Figure 2 for support points.)

• May be suspended from above (See Page 7, Fig-
ure 2) or from wall brackets of sufficient strength
to support the heater as listed in the Dimension
Data Table on Page 5, Section 4.1. Drop rods
must be a minimum of 10 mm diameter mild
steel. Four suspension points (M10 nuts) are
located on top and back side of the heater.

• Must be installed in a manner which allows
access to all serviceable components.

SECTION 3: CRITICAL CONSIDERATIONS

3.8 Flue

Choose heater siting to allow for the proper location
of the flue. Each heater must be fitted with an
individual and correctly sized sealed flue system
(See Page 9, Section 6).

No other appliance may be connected to the flue.
For room sealed installation, the air intake must be

the same size sealed system and the flue/air intake
must terminate at an approved concentric wall or
roof terminal.

3.3 Minimum Required Installation Clearances

Clearances around the heater and flue must be as
indicated on Page 4, Figure 1; Page 9, Figure 5
through Page 10, Figure 7 to ensure access for
servicing, and correct operation.

3.4 Clearances to Combustibles

Clearances must be as indicated on Page 4, Figure

1. If clearances to combustibles are not indicated,

then installation clearances apply.

3.5 Ventilation

It is important to ensure that there is adequate air
circulation around the heater to supply air for
combustion, ventilation and distribution in
accordance with local and national codes.

3.6 Gas Supply

It is important that the gas supply pipe is sized
correctly to provide the inlet pressure as stated on
the heater data plate. The gas supply pipe and
electrical connections must not support any of the
heater's weight.

3.7 Electrical Supply

A permanent 230 V 50 Hz 1 Ø electrical supply is
required at the main electrical terminals. The heater
also requires suitable energy controls in accordance
with Section 9.

3

COMBAT® CTCU UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

WARNING

Fire Hazard

Some objects will catch fire or explode when placed
close to heater.

Keep all flammable objects, liquids and vapours the
required distance away from the heater.

Failure to follow these instructions can result in death,
injury or property damage.

Figure 1: Installation Clearances and Clearances to Combustibles

Installation Clearances

Roof Terminal

Air

Intake

Wall

Terminal

Flue

25 cm

15 cm

3 m

2.5 - 3.5 m*

Roof Terminal

3 m

* Heaters may be mounted at a higher level if destratification

fans are installed.

The heater must always be installed at least 1.8 m above the floor.
The flue pipe must have clearance from combustibles by 5 cm.

Clearances to Combustibles

15 cm

50 cm** 10 cm

30 cm

**80 cm is necessary to service

heater.

If installed at low levels where individuals can come in contact with hot heat exchanger components,
adequate guarding must be provided.

All distances are minimum clearance requirements for service access, air flow and safety.

4

SECTION 4: SPECIFICATIONS

4.1 CTCUA (All Models)

Top View

448 26514

422

Mounting

Holes

463

C

120

SECTION 4: SPECIFICATIONS

4 x M10 Captive Nuts Provided

Air Intake
(Optional Position)

Flue
(Optional Position)

171

Rear View

4 x M10 Captive Nuts Provided

448

B

Mounting

Holes

728

* 140 for 27 - 32

Dimension Data - CTCUA (All Models)

Model CTCU-7 CTCU-11 CTCU-15 CTCU-22 CTCU-27 / 32

Height

A

Mounting Hole Spacing

B

Centre of Flue (Top Option)

C

Centre of Flue

D

Weight kg 28 30.5 38.5 41 52.3

mm
(in)

mm
(in)

mm
(in)

mm
(in)

120

*

Air Intake

Electrical
Connection

Lockout Reset
Gas Supply

304

(12.0)

239

(9.4)

151

(5.9)

68

(2.7)

Flue

171

Air Intake
on Model 22

D

45

85

304

(12.0)

239

(9.4)

151

(5.9)

68

(2.7)

A

End View

450

(17.7)

385

(15.2)

151
(5.9)

68

(2.7)

514

450

(17.7)

385

(15.2)

172

(6.8)

46

(1.8)

660

578

(22.8)

513

(20.2)

149

(5.9)

59

(2.3)

5

COMBAT® CTCU UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

4.2 General Technical Data Table (All Models)

Model CTCU-7 CTCU-11 CTCU-15 CTCU-22 CTCU-27 / 32

CTCUA, Axial Fans

Total Electrical Load W 260 274 336 384 345

R u n C u r ren t A 1.1 1. 2 1. 5 1. 7 1. 5

Start Current A 1.7 1.8 2.5 2.9 2.6

3

Air Flow m

Sound Pressure Level at 3 m

/h 1120 1220 2710 2750 4474

[NR]

dB(A)

[31]

37

[35]

41

[39]

45

[42]

48

[42]

48

Flue and AIr Intake

Flue and Air Intake Size mm Ø 80 80 80 80 100

*Maximum Straight Flue/Air Intake m 2.5 4 5 5 5

Electrical load at 230 V 50 Hz measured by calculating from total run current of appliance.

* Do not exceed the maximum length of flue stated or heater may not operate properly.

Reduce the maximum length stated by 1 m for each 90° bend installed.

**If minimum air flow requirements are not met, then temperature limit devices will shut down the heater.

4.3 Technical Data Table (All Models)

Appliance Category II

Heat Input

Gross CV

Heat Input

Net CV

Approximate

Heat Output

Natural Gas (G20) Data - Inlet Pressure 20 mbar (7.8 in WG) Min. 17 mbar (6.8 in WG) Max. 25 mbar (10 in WG)

Burner Pressure mbar 9.5 9.5 9.5 9.5 9.0 9.0

Gas Rate

Natural Gas (G25) Data - Inlet Pressure 25 mbar (10 in WG) Min. 20 mbar (7.8 in WG) Max. 30 mbar (12 in WG)

Burner Pressure mbar 9.0 9.0 9.5 9.2 9.2 9.3

Gas Rate

LPG / Propane (G31) Data - Inlet Pressure 37 mbar (14.6 WG) Min. 25 mbar (10 in WG) Max. 45 mbar (18 in WG)

Alternative where permitted 50 mbar (20 in WG) Min. 42.5 bar (17 in WG) Max. 57.5 mbar (23 in WG)

Burner Pressure mbar 25.6 29.4 29.4 28.6 29.9 29.9

Gas Rate

2H/L 3B/P

Model CTCU-7 CTCU-11 CTCU-15 CTCU-22 CTCU-27 CTCU-32

kW

(Btu/h) x (1000)

kW

(Btu/h) x (1000)

kW

(Btu/h) x (1000)

3

m

/h

3

ft

/h

3

m

/h

3

ft

/h

3

/h

m

3

kg

/h

8.5
29

7. 7
26

7. 1
24

0.8
29

0.9
33

0.3

0.16

13.4
46

12.1
41

11.1
38

1. 3
45

1. 5
52

0.5

0.25

6227.5 9433

18.3

16.5

24.8

56

15.1
52

1. 7
62

2.0
72

0.7

0.34

0.51

85

23
78

2.6
93

3

108

1

113

29.7
101

27.2

93

3.1

110

3.6

127

1. 2
.61

38.5
131

34.7
118

31.7
108

3.6

127

4.2

148

1. 4
.71

LPG / Butane (G30) Data - Inlet Pressure 29 mbar (11,4 in WG) Min. 20 mbar (7.8 in WG) Max. 35 mbar (13.8 WG)

Burner Pressure mbar 19.2 21.9 22.9 21.4 21.4 22.4

3

/h

Gas Rate

m

kg

3

/h

0.2

0.09

0.4

0.14

0.5

0.19

0.8

0.29

Gas rates corrected to standard conditions 1013.25 mbar 15° C.

6

.9

.34

1. 1
.42

SECTION 5: HEATER INSTALLATION

Cone Point

Set Pin

Window

Clamp

Unistrut

10 mm
Steel
Drop Rod

Nut

Washer

Riv

Nut

10 mm
Steel
Drop Rod

Washer

Nut

Unistrut

Channel Nut

5.1 General

Heaters are designed for installation above 1.8 m.
These heaters must be installed within the heated
space. Duct delivery systems are not permitted with
axial fans. When handling or supporting the heater
from below, ensure that the weight is taken at the
support points.

5.2 Shelf Mounting and Suspension

WARNING

Crush Hazard

Use 10 mm steel drop rod
minimum.

Failure of the supports can
result in death, injury
or property damage.

For typical suspension, See Page 7, Figure 2.

Figure 2: Suspension Methods

SECTION 5: HEATER INSTALLATION

5.3 Wall Mounting

For typical suspension, See Page 8, Figure 3.
Heaters blowing parallel to the wall can only be
installed with the service door away from the wall.

The wall mounting brackets must be attached to a
suitable wall through all mounting holes. Screw
sizes less than M10 may not be used. In order for
the wall mounting brackets to adequately carry the
weight of the heater, it must be installed with best
building practice.

Ensure all suspension hardware
is torqued to a minimum
of 27 Nm (20 ft lbs).

NOTE: For vertical installations, use the mounting points on the rear of the unit.

Shelf Mounting

Brackets

Support Points

Existing cabinet screws must be re-used.

Description Part Number Qty.
Shelf Mounting Bracket
Kit

She l f M o un t in g Bra ck et ( 2) 1111115 10 2
Screw #10 x 1/2"
Type AB Phil HWH Z (2)

111115 10 K

94311008 2

7

COMBAT® CTCU UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

Figure 3: Shelf Mounting and Hanging Suspension

Shelf Mounting

Hanging

Shelf
Mounting
Brackets
(Fasten to
Wall Mounting
Bracket)

Wall Mounting
Bracket Arm
(Right & Left)

M8 Bolt
Washer
Lock Washer
M8 Locknut

Wall Mounting

Torque to 4.5 Nm (40 in lb)

Bracket Diagonal

Wall Mounting
Bracket Vertical

Description Part Number Qty.
Wall Suspension Mounting Bracket Kit 11111511K 1

Description Part Number Qty.
Wall Shelf Mounting Bracket Kit 11111512K 1

Wall Suspension Mounting Bracket Kit 1111510K 1
She lf M o un t in g Br a ck et K it 111115 11K 1

Wall Mounting Bracket Arm Left 111WALL1L 1
Wall Mounting Bracket Arm Right 111WALL1R 1
Wall Mounting Bracket Vertical 111WAL2 2
Wall Mounting Bracket Diagonal 111WAL3 2
M8 x 85 mm Hex Head Bolt 97311405 6
M8 Lock Nut with Nylon Insert 92204504 6
M8 Flat Washer 95204502 6
M8 Lockwasher 96404502 6

Hardware provided to construct mounting bracket assembly only.

M10 Fasteners

Figure 4: Vertical Louvres (Optional)

Remove Horizontal
Louvres

Push in

Louvre and compress

spring to remove

(opposite end first)

Description Part Number
Vertical Louvre Kit
CTCU 7 and 11

Vertical Louvre Bracket 11111903
#10 Screw S103
CTCU 7-11 Vertical Louvres 11111901
Louver Spring 90901200
Instruction Sheet 91040021

111119 01 K

Description Part Number
Vertical Louvre Kit
CTCU 15 and 22

Vertical Louvre Bracket 11111903
#10 Screw S103

Instruction Sheet 91040021

111119 0 0K

Install Vertical
Louvre Brackets
(top and bottom)
with supplied
screws.

Install Vertical
Louvres and Springs
into Brackets
with Springs at Top

Description Part Number
Vertical Louvre Kit
CTCU 27 and 32

Vertical Louvre Bracket 11111903

#10 Screw S103
27-32 Vertical Louvre 11111902
Instruction Sheet 91040021

11111902K

For models 15 and 22, horizontal louvres are re-used.

8

SECTION 6: FLUE INSTALLATION

6.1 Changing Flue and Air Intake Orientation

The heater is sold with horizontal flue and fresh air
connections as standard. If vertical flue and fresh air
connections are required, follow the instructions on
Page 29, Section 15.4.

6.2 Flue Installation

SECTION 6: FLUE INSTALLATION

Figure 5: Flue and Roof Detail

Flue

Terminal

WARNING

Fire Hazard

Some objects will catch fire or explode when placed
close to heater.

Keep all flammable objects, liquids and vapours the
required distance away from the heater.

Failure to follow these instructions can result in death,
injury or property damage.

The flue must terminate outside of the building.
Flues and air intakes must be a fully sealed system
and correctly sized for the model. Flues should be
assembled as detailed on Page 9, Figure 5 through
Page 10, Figure 7. The joints between the flue
terminal and the roof or wall must be properly
sealed. If the flue passes through a wall or ceiling of
combustible material it must be enclosed by a
sleeve of non-combustible material and be
separated from the sleeve by at least a 25 mm air
gap.

Flues and air intakes must be adequately
supported so that the heater does not bear the
weight of the pipes.

For flue termination See Page 9, Figure 5 through
Page 10, Figure 7.

6.3 Type C

Room Sealed.
The heaters are designed to be installed as room

sealed appliances. The flue and air intake are run as
separate pipes to the special concentric wall or roof
terminal. See Page 10, Figure 7. The wire mesh
inside the fresh air adapter on the heater must be
removed prior to installation.

, C32 & C62 Appliance

12

Roof

25 mm Air Gap to

Combustible Material

Masterflash

Soaker Flashing

or Rain Collar.

Metal Sleeve

Flue

6.4 Type B

Appliance

22

The flue must be fitted with a low resistance
terminal. See Page 9, Figure 5 through Page 10,
Figure 6.

9

COMBAT® CTCU UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

Figure 6: Vertical and Horizontal Flue Termination - Type B

Roof Terminal

Masterflash

Flue

Vertical
Option

Flue

Horizontal
Option

Appliance

22

Masterflash

Wall
Terminal

Figure 7: Vertical and Horizontal Flue Termination - Type C

Roof Terminal

Plastic Cup

Masterflash

Manifold

Air Intake

Vertical
Option

Remove Internal

Wire Mesh

Flue

Horizontal
Option

& C62 Appliances

12 C32

Wall
Plate

10

Flue

Air Intake

Remove Internal

Wire Mesh

Manifold

Wall
Terminal

SECTION 7: AIR SUPPLY

7.1 Room Sealed Installation

When installed as a room sealed heater, the air for
combustion is drawn in from outside the building. It
is important to ensure that there is adequate
ventilation to provide air for the distribution fan.

7.2 Open Flued Installation

It is important to ensure that there is adequate air
supply at all times for both combustion and heating
requirements in accordance with local and national
codes.

7.2.1 Heaters Installed Within the Heated Space

Where the volume of the heated space is greater
than 4.7 m

3

per kilowatt of total rated heat input and
the air change rate is at least 0.5/h, additional high
and low level ventilation will not be required.

For a building having an air change rate less than

0.5/h, ventilation will be necessary in accordance
with local and national codes. Ventilation direct to
outside must be provided as follows:

• Heaters up to 70 kW heat input 5.0 cm

2

per kW

of rated heat input

SECTION 7: AIR SUPPLY

7.3 Building Ventilation

Where ventilation is required, air must be taken from
an outside point where it is not likely to be
contaminated or obstructed.

Where natural ventilation is used, suitable ventilation
with outside air at low level must be provided in
accordance with Section 7.2.1 and local and national
codes.

Where mechanical ventilation is used, extract rate
must be 5% - 10% less than the inlet rate. The
mechanical ventilation must be interlocked with the
burner on the CTCU heater.

11

COMBAT® CTCU UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

SECTION 8: GAS PIPING

8.1 Connections

Connect the heater to the gas supply ensuring that

WARNING

the final connections are as follows:

• Gas supply pipe work is run in medium or heavy
gauge tubing in compliance with local and
national codes.

• The gas supply pipe is adequately sized to carry
the total volume of gas for the complete

Fire Hazard

Connect gas supply according to Figure 8.

Gas can leak if not installed properly.

Failure to follow these instructions can result in death,
injury or property damage.

installation.

• An isolating valve and union connection should
be used and fitted into the supply adjacent to the
heater.

• For suspended heaters, use an approved metal
flexible connection between the isolating valve
and the heater. To reduce pressure loss, use

It is important that the gas supply pipe and the
electrical connections do not support any of the

one pipe size larger than the heater gas
connection.

heater’s weight.
A gas meter is connected to the service pipe by the

gas supply company. An existing meter should be
checked, preferably by the company, to ensure that

IMPORTANT - The complete installation must be
purged and tested for gas soundness in accordance
with local and national codes.

the meter is adequate for the rate of gas supply
required.

Installation pipes must be fitted in accordance with
local and national codes. Pipe work from the meter
to the heater(s) must be of adequate size. Pipes of
smaller size than the heater inlet gas connection
should not be used.

Figure 8: Gas Connection with Stainless Steel Flex Connector

• Hold gas nipple securely
with pipe wrench when
attaching the flex gas
connector.

• Do not twist flexible
gas connector.

• Ensure all joints are
gas tight.

Do not bend flexible
gas connector sharply.

Gas Isolating Valve

Option A:

Stainless Steel
Flex Gas
Connector

Option B:

Medium or Heavy
Gauge Tubing
Gas Connector

12

Union

Connection

Drip Leg

Cap

SECTION 9: WIRING AND ELECTRICAL INFORMATION

9.1 Electrical Supply

All heater models need a constant 230 V 50 Hz 1 Ø
supply connected to terminals L

, N & Earth.

1

Polarity "L & N" must be correct. The voltage
between neutral and earth should be 0 and never

9.2.3 Remote Frost Thermostat

When required, connect to L
room thermostat. Locate within the heated space
adjacent to the most vulnerable equipment that

requires protection. See Page 14, Section 9.3.
exceed 15 volts.
All heaters and controls must be correctly earthed.
All external wiring must comply with the relevant

local codes. Wire specification H05VV-F.
External controls must have the same constant

230 V 50 Hz supply.

9.2.4 Remote Fan Controls

The fan will operate automatically providing there is

a constant 230 V supply.

A switch or control wired between L

allow external control of the fan(s).

The fan may be controlled to operate continuously
An isolator with a contact separation of at least

3 mm on all poles must be installed adjacent to, but
not attached to, the heater to disconnect all supplies

from an external control, with the burner cycling on

and off, providing that the fan run-on at close down

is not impaired.
to the heater and any remote control. This switch

should be fused to 5 A.

The final connection to the heater should be made
by flexible cable or conduit to the 7 pole plug using 1

2

mm

cable on all models.

SECTION 9: WIRING AND ELECTRICAL INFORMATION

and T2 parallel to the

1

and T1 will

1

WARNING

Electrical Shock Hazard

Disconnect electrical power before servicing.

Failure to follow these instructions can result in
death or electrical shock.

9.2 Remote Controls

The heater is designed to be operated by controls
installed remote from the heater. See Page 14,
Section 9.3.

9.2.1 Burner Controls (Thermostat)

Controls to operate the burner must be connected
between L

9.2.2 Positioning Room Thermostats or
ROBERTS GORDON

A room thermostat or ROBERTS GORDON
control should be mounted on a wall or column at a
height of approximately 1.5 metres from the floor to
measure the ambient temperature. It should be clear
of both cold draughts and the direct path of warm air
from the heater.

and T2.

1

®

Control

®

13

COMBAT® CTCU UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

9.3 CTCUA Wiring Diagram Models 7 - 32

GAS

SITE WIRING

VALV E

GREEN/YELLOW

BLUE

BROWN

YELLOW

1112 7910 8 564

IGNITION CONTROL

REMOTE LOCKOUT INDICATION

THERMOSTAT

REMOTE LOCKOUT RESET

NEUTRAL

REMOTE FAN ON

GROUND

LINE

L1NT1T2S3B4

L1NT1T2S3B4

7 POLE PLUG

WHITE
YELLOW
BLACK

GROUND AT LIMIT

THERMOSTAT

PRESSURE SWITCH

LOCKOUT

RESET WITH

INDICATOR

LIGHT

4 5

1 2

WHITE

BLACK

BROWN

PINK

PURPLE

GREY

23 1

SENSE

IGNITION CONTROL

BLACK

230 V
50 Hz

SUPPLY

7 POLE SOCKET

BROWN

RED

BLACK

FAN DELAY THERMOSTAT

BLUE

BROWN

BLUE

THERMOSTAT

LIMIT

E

N

L

LEN

BROWN

AXIAL FANCOMBUSTION FAN

EMC FILTER

NOTE:

If any of the original wire supplied with the heater must be replaced, it must be replaced with wiring
material having a temperature rating of at least 105° C and 600 volts.

IGNITION

BLACK

14

SECTION 10: COMMISSIONING

Installation, service, commissioning and annual
inspection of the heater must be done by a
contractor qualified in the installation and service of
gas-fired heating equipment. Read this manual
carefully before installation, commissioning,
operation, or service of this equipment. All
components are accessed via the door secured by 4
sheet metal screws. Opening the door exposes live
electrical connections and hot components.

WARNING

Electrical Shock Hazard

Use extreme caution while commissioning.

Failure to follow these instructions can result in
death or electrical shock.

SECTION 10: COMMISSIONING

1. Check that all site wiring is connected in
accordance with the appropriate wiring diagram
on Page 14, Section 9.3.

2. Check the correct fuse size is fitted;
See Page 13, Section 9.1.

10.1.3 Gas Supply

All aspects of the gas installation including the gas
meter must be inspected, tested for soundness and
purged in accordance with local and national codes.

Ensure that the air is fully purged from the heater
inlet pipe up to the main gas valve inlet test nipple.

10.1.4 Mechanical Checks

1. Check that the fan is free to run and
delivery louvres are turned to give required air
deflection.

2. Check that the flue (and air intake for room
sealed) is installed in accordance with these
instructions and local regulations.

NOTE: The limit thermostat is sealed at the factory
and is not adjustable.

10.1 Pre-Commission Checks
All pre-commission checks must be carried out

before lighting the heater.

Ensure that the heater and all controls are suitable
for the gas, pressure and electrical supply to which
they are to be connected.

10.1.1 Louvres

Where fitted, the air delivery louvres need to be set
during commissioning to give the required air
distribution (optional vertical louvres).

WARNING

Cut Hazard

10.2 Begin Commissioning

10.2.1 Before Operating the Heater

To ensure that all the controls are in safe working
order, operate the heater for the first time with the
isolating gas valve turned off.

1. Turn off the isolating gas valve.

2. Using the installed external control, turn on the
burner. The automatic sequence will now begin
as described on Page 16, Figure 9.

There will be no ignition of the burner and lockout
will occur, which proves the controls are operating
correctly.

Tur n off gas and electrical supply before maintenance.

Fan can start automatically at any time.

Failure to follow these instructions can result in severe
injury or

10.1.2 Electrical Checks

All pre-commission checks must be carried out
before commissioning the heater.

product damage.

15

COMBAT® CTCU UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

Figure 9: Automatic Burner Control Box Sequence

Burner sequence for Honeywell S4565C

START

Supply 230 V

Flue Fan

Pressure Switch

Ignition Spark

Start Gas Valve

Flame Signal

NO

P

C

NC

*Purge time begins at pressure switch change over.

30 Sec. Purge*

ts = 10 seconds

Required Incoming Signals

Signals Output By Control

If at any stage the flame fails, the control will go into "lockout". The red light inside the RESET
switch will illuminate and the control will need to be manually reset before any further start
attempt can be made.

Figure 10: Gas Valve for Heater Models 7 - 32

CLOSE
DOWNRUN

End View

Ignition

Output

Flame

Probe

Connection

Regulator

(Under Cover)

Outlet Pressure

Inlet Pressure

Screw

Ignition Control
(Plugs into Gas Valve)

12 Cable Connector

Gas Inlet

16

SECTION 10: COMMISSIONING

10.2.2 Commissioning the Gas Valve (All Gases)

10.2.2.1 Check Burner Gas Pressure

1. Loosen the screw cover of the outlet (burner)
pressure test point and connect a manometer.

2. With the burner firing, measure the pressure on
the manometer. To adjust the burner pressure,
remove the regulator cover from the valve and
turn the regulator adjustment screw to set the
required burner pressure as stated in the Tech­nical Data Tables for the correct gas and model
on Page 6, Section 4.3.

NOTE: If the correct burner pressure cannot be
reached, then check the inlet pressure to the valve,
with the burner firing. See Technical Data Tables on
Page 6, Section 4.3 for inlet pressure requirement.

Do not continue to adjust the regulator if the
pressure is not changing.

If the inlet pressure is too low to allow correct burner
pressure setting, then the gas inlet pressure must be
corrected before completing the commission.

Check Gas Rate

1. After burner pressure adjustment, allow the
heater to operate for at least 15 minutes and
then re-check settings.

2. Remove the manometer and refit all covers to
the valve and tighten the screw of the outlet
pressure tap.

3. Check gas flow rate at gas meter.

10.2.5 Turning Off the Heater

Set the external controls to the "OFF" position and
the main burner will stop.

The fan will run until it is stopped automatically by
the fan thermostat.

Do not use Electrical Isolator for control of
heater. Electrical Isolator will switch off the fan.
Heat exchanger could be damaged. Warranty will
not cover damage to the heat exchanger if
operated improperly.

10.2.6 External Controls

External Controls may include time switch, room
thermostat and frost thermostat. Operate each
control to ensure that they function correctly. Set the
time switch (if fitted) and room thermostat to the
users’ requirements.

10.3 Complete the Commissioning

Ensure that all covers are fitted correctly and all test
points are properly sealed.

10.3.1 Instruction to the User

Explain the controls of the heater to the user
including how to turn it on and off, using the controls
fitted on site.

Give this manual to the user.
Ensure that the user is shown and understands the

importance of maintaining clearances to
combustibles and the user instructions on Page 18,
Section 11 through Page 19, Section 11.5 and all
warnings defined in this manual.

10.2.3 Combustion Testing

The only adjustment to alter combustion
performance is burner pressure. Combustion quality
must be tested to prove correct heater operation.
Incorrect results will indicate faults with the
installation or appliance.

Combustion testing must be carried out with all
covers in place. The flue gas is sampled in the flue,
within 1 meter of the heater. The values of CO

2

should be between 5.7% to 8.0% for natural gas and

6.8% to 9.2% for LPG dependant upon model.
The CO will be up to 80 ppm (0.008%) dry, air free

dependant upon model. Temperature rise of the flue
gases above ambient should be approximately
130° C to 160° C. Seal test hole in flue after testing.

10.2.4 Pressure Switch

The pressure switch is factory pre-set for each
model and is not adjustable.

17

COMBAT® CTCU UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

SECTION 11: USER INSTRUCTIONS

11.1 User Instructions

The CTCU heaters are fully automatic and operate
from the external controls fitted on site.

The only user controls at the heater are the:
Burner Lockout

Reset Button ................ See Page 18, Section 11.3.3

Limit Thermostat Reset See Page 18, Section 11.3.2

These are hand reset devices to give further
protection against fan failure.

WARNING

Electrical Shock Hazard

Disconnect electrical power before servicing.

NOTE: To reset, the heat exchanger must be cool.

Description Part Number

Limit Thermostat 90412100

Press to reset

WARNING

Failure to follow these instructions can result in
death or electrical shock.

11.2 Heater Operation

When the heater has been switched on by the
remote controls installed on site, the main burner will
automatically turn on.

The burner control box will control the safe ignition
of the flame.

All heaters require a constant gas and electricity
supply which must not be interrupted during the
normal operation of this heater.

Figure 11: Heater Operating Sequence

THERMOSTAT

CALL FOR

HEAT

BURNER

RUN

FAN

ON

ON

ON

2-3 MINUTES

CLOSE
DOWN

RUN ON

11.3 Common User Controls

11.3.1 Fan Thermostat

The fan thermostat is located inside the access door
at the top of the heater. See Page 28, Section 15.3.

This control ensures the heater does not blow cold
air in the normal heating cycle.

11.3.2 Limit Thermostat

The limit thermostat is located inside the access
door of the heater. See Page 28, Section 15.3. This
control protects the heat exchanger against
overheating.

Explosion Hazard

If control locks out, do not make more than 3

attempts to restart the heater.

Dangerous gas mixtures can build up.

The fault must be
registered installer or service engineer.

Failure to follow these instructions can result in
death, injury or property damage.

traced and repaired by a

11.3.3 Burner Lockout Reset Button

The red warning light on the back of the heater will
illuminate when the control has gone to lockout. This
may be caused by flame failure. Press the reset
button on the back of the heater (See Page 5,
Section 4.1) or the remote reset if installed on site.

11.4 Lighting Instructions

11.4.1 To Turn On Heater

1. Ensure that the electrical and gas supplies to
the heater are on. Check that the on site con­trols are “ON”.

NOTE: The thermostat setting must be above the
ambient temperature for the heater to operate.

2. The automatic firing sequence will begin as
described on Page 16, Figure 9. The heater will
now operate automatically under the control of
the on site controls. Following long shut down
periods, the control may go to lockout. See
Page 18, Section 11.3.3.

18

11.4.2 To Turn the Heater Off

Set the installed remote controls to the "OFF"
position.

The burner will turn off immediately.
The fan will continue to run for a few minutes.
To restart, turn the control used above to "ON".

11.5 Simple Fault Finding

Some possible reasons for the heater not operating
are:

1. Gas supply not turned "ON".

2. Electricity supply not turned "ON".

3. The time and/or temperature controls are not
"ON".

4. The limit thermostat may have operated. This
may be caused by an interruption of the electri­cal supply or failure of the distribution fan.

If the limit thermostat persistently operates, there is
a fault which must be investigated by a contractor
qualified in the installation and service of gas-fired
heating equipment.

11.5.1 Simple Fault Finding (Burner Faults)

If the burner fails to ignite for any reason, it will go to
lockout. This will be indicated by the red light on the
back of the heater or at the remote indicator (if
fitted).

1. Press in and release the lockout reset button. If
a remote reset is not fitted, a reset button is on
the back of the heater.
See Page 5, Section 4.1.

SECTION 11: USER INSTRUCTIONS

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. Leave the building.

6. Immediately call your local gas
supplier after leaving the building.
Follow the gas suppliers
instructions.

7. If you cannot reach your gas
supplier, call the Fire Department.

WARNING

Fire Hazard

Do not store or use petrol or other
flammable vapours and liquids in the
vicinity of this or any other appliance.

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.

Lockout should not occur during normal operation of
the heater and indicates there is a fault condition
which must be corrected.

19

COMBAT® CTCU UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

SECTION 12: SERVICING

12.1 Servicing Instructions

After commissioning, the heater will require
maintenance to be carried out annually. If the heater
is used in a dirty or dusty area, more frequent
maintenance may be necessary.

Installation Code and Annual Inspections: All
installations and service of ROBERTS GORDON
products must be performed by a contractor qualified in
the installation and service of gas-fired heating
equipment and conform to all requirements set forth in
the ROBERTS GORDON
governmental authorities pertaining to the installation,
service and operation of the equipment.
To help facilitate optimum performance and safety,
Roberts-Gordon recommends that a qualified contractor
annually inspect your ROBERTS GORDON
and perform service where necessary, using only
ROBERTS GORDON

®

manuals and all applicable

®

replacement parts.

®

®

products

2. Clean any deposits from the main burner which
may have formed in the injectors or venturi of
the burner. See Page 27, Section 15.2.

3. Remove the ignition electrode and flame probe.
Check condition of ignition electrode and flame
probe. Clean off any deposits which may have
been formed, check condition of ceramic
insulators. Replace as necessary.

12.3 Fan/Motor Assembly Maintenance

The main fan bearings are permanently sealed and
do not need lubrication. Before cleaning, turn off gas
and electrical supply. Remove the fan and use a
small brush or duster to clean the fan blades from
each side. Replace fan when done.

12.4 Heat Exchanger Maintenance

The heat exchanger will remain clean unless a
problem has developed with combustion. Inspect the

WARNING

heat exchanger. Look for signs of overheating at the
front tubes which may indicate burner over firing or
persistently low air flows.

Cut Hazard

Tur n off gas and electrical supply before maintenance.

Fan can start automatically at any time.

Failure to follow these instructions can result in severe

injury or

product damage.

NOTE 1: After any maintenance or repair work,
always test fire the heater in accordance with the
commissioning instructions on Page 15, Section 10
through Page 17, Section 10.3.1 to ensure all safety
systems are in working order before leaving the
heater to operate. Minor faults may be traced by
using the troubleshooting charts on Page 22,
Section 14 through Page 25, Section 14.5.

NOTE 2: Check all gas pipes and pipe joints to
ensure there are no cracks or gas leaks. Any cracks
in the pipes or pipe joints must be repaired.

12.5 Gas Control Valve Maintenance

No regular maintenance is required on this device.
To change gas control valves, See Page 26, Step

15.1 and Page 30, Section 15.5.

Do not repair or disassemble on site.
Replace faulty gas valves with genuine

ROBERTS GORDON

®

replacement parts.

12.6 Flue Fan

The flue fan should not require maintenance.
However, if the air pressure switch is causing burner
lockout, then remove the flue fan from the vent box
by unscrewing the three screws at the mounting
plate. Remove the four screws attaching the
mounting plate to the fan inlet (See Page 29,
Section 15.4). Ensure that the fan is free to run and
that the fan wheel is clean.

NOTE 3: Inspect all suspended components and
hardware. Insure that they are in good condition,
properly tightened, and corrosion free.

12.2 Burner Maintenance

1. Open the door and remove the burner compart­ment cover. See Page 27, Section 15.2.

20

SECTION 13: CONVERSION BETWEEN GASES

13.1 General

Conversion between gases will require a change of
burner injectors and the gas valve re-commissioning
to the new conditions.

13.2 Burner Conversion

Conversion of the burner assembly from one gas to
the other is the same for all types of heaters.

1. Remove the burner compartment cover as
shown on Page 27, Section 15.2.

2. Remove the 4 screws holding the manifold and
pull out the manifold.

3. Remove inshot burners by rotating them and
sliding out the bracket.

4. Remove the main burner injectors.

5. Replace with the injectors for the new gas
ensuring a gas tight seal.

6. Refit all components in reverse order.

SECTION 13: CONVERSION BETWEEN GASES

13.3 Gas Valves

All gas valves used on the CTCU have pressure
regulators that may be set to operate on natural gas
or LPG.

Conversion is carried out by re-setting the burner
pressure to the value in the data table during
commissioning. See Page 6, Section 4.3.

Ensure that the gas inlet pressure to the heater is
correct for the new gas, and that the gas supply has
been purged of the old gas.

21

COMBAT® CTCU UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

SECTION 14: TROUBLESHOOTING

14.1 General

WARNING

Explosion Hazard

Installation must be done by a registered installer/
contractor qualified in the installation and service of
gas-fired heating equipment or your gas supplier.

Failure to follow these instructions can result in death,
injury or property damage.

Start

Are gas & electrical

supplies on?

Ye s

Is Red lockout

warning light on?

No

Does the fan run?

Ye s

Ye s

With external controls on,

does the burner continue

through the heating cycle?

No

Ye s

No

No

Turn on supplies.

Use 14.2 to test burner.

Use 14.5 to test fan.

Has burner Locked Out?

Use 14.2 to test burner.

Ye s

No

The limit thermostat has

tripped.

See Section 11.3.2.

Ye s

Replace axial fan.

Replace limit thermostat.

No

Ye s

Heater Operating

TROUBLESHOOT ENDS.

No

If problems persist, contact

Roberts-Gordon Ltd. at

Tel: [phone]

www.rg-inc.com

For your safety and optimum heater performance, use only ROBERTS GORDON® replacement parts.

Conduct Commissioning procedure as shown on Page 15, Section 10.

22

14.2 Troubleshooting For Automatic Ignition Burner Systems

Start

SECTION 14: TROUBLESHOOTING

WARNING

Are gas & electrical

supplies on?

Ye s

Are external controls on?

Ye s

Is red lockout light on?

No

Does flue fan run?

No

No

Ye s

No

Turn on supplies.

Turn on controls.

Press in lockout reset button

on rear of heater or remote

reset button if fitted.

Is 230 V supply at fan

connections?

Burner control faulty or plug
in connections faulty. Repair

or replace as necessary

No

Ye s

Do not touch ignition components.

Voltage from ignition components is high.

Failure to follow these instructions can
result in death or electri

Flue fan faulty; replace

Electrical Shock Hazard

cal shock.

Ye s

Does air pressure switch

change over?

Ye s

Wait 30 - 40 seconds.

Is ignition spark operating?

Ye s

Does the flame light?

Ye s

Is red lockout light on?

No

Heater Operating

TROUBLESHOOT ENDS.

Check for too much flue/air inlet

duct. Check for blockage in

No

No

No

Ye s

No

combustion air circuit.

Check for faulty air pressure

switch. See Section 15.5.

Is HT lead okay and

connected?

Is spark electrode okay?

Is the gas valve operating?

To test valve,

See Section 14.4.

Is the flame current at

least 1 µAmp DC when

the flame lights?

If problems persist, contact

Roberts-Gordon Ltd. at

Tel: [phone]

www.rg-inc.com

Ye s

Ye s

Ignition control faulty;

See Section 15.6.

No

Replace valve.

Trace fault in supervision

system. See Section 14.3.

replace.

For your safety and optimum heater performance,

®

use only ROBERTS GORDON

replacement parts.

Conduct Commissioning procedure as shown
on Page 15, Section 10.

23

COMBAT® CTCU UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

14.3 Troubleshooting for Flame Supervision System

To measure flame current, connect a 0 - 50 μA DC meter in
series with the flame probe. If the meter reads negative
values, then reverse the test leads.

START

Connect a DC ammeter in

series with the flame probe.

Is the flame present and

at least 1 µA DC flame

current?

Ye s

Is there a current flowing in the

flame probe circuit with no

flame present?

No

Does lockout occur when

there is a flame present?

No

Heater Operating

TROUBLESHOOT ENDS.

No

Ye s

Ye s

No

Use Section 14.1 to

trace the fault.

Is the connecting lead

damaged? Is the flame probe

damaged or touching earthed

components?

Is inlet burner gas pressure

correct? Is live and neutral

polarity correct? Is

flame probe circuit correct?

No

Repair or replace as

necessary.

If problems persist, contact

Roberts-Gordon Ltd. at

www.rg-inc.com

Repair or replace as

Ye s

Ye s

necessary.

Control box faulty.

Replace with correct type.

NOTE: Minimum flame probe current 1 μA DC. Typical flame probe current 3-5 μA DC.

24

14.4 Troubleshooting for Solenoid Valves

START

SECTION 14: TROUBLESHOOTING

Is gas pressure at inlet of the

valve correct for gas type?

Note pressure found.

Ye s

Does gas pressure at outlet

of the valve rise when

valve turns on?

Ye s

Ye s

Does gas pressure at

outlet of valve return to zero or

lower when valve turns off?

Ye s

Valve Operating

TROUBLESHOOT ENDS.

No

No

No

No

Fault elsewhere.

Valve or ignition control

faulty. Replace with
one of correct type.

Valve faulty.

Replace with one of

correct type.

If problems persist, contact

Roberts-Gordon Ltd. at

Tel: [phone]

www.rg-inc.com

14.5 Troubleshooting for Main Fan

START

Does fan run

automatically?

Ye s

Does fan turn on and

off while burner is firing

continously?

No

Fan Operating

TROUBLESHOOT ENDS.

Ye s

No

Is power supply 230 V at

No

terminals T

Fan motor faulty.

Replace with correct type.

Replace fan

delay thermostat.

If problems persist, contact

Roberts-Gordon Ltd. at

Tel: [phone]

www.rg-inc.com

Ye s

1 to N?

No

Is there 230 V between

terminals L

1 and N?

Ye s

Replace fan

delay thermostat.

For your safety and optimum heater performance, use only genuine ROBERTS GORDON® replacement
parts.

Conduct Commissioning procedure as shown on Page 15, Section 10.

25

COMBAT® CTCU UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

SECTION 15: REMOVAL AND REPLACEMENT PARTS

See warnings and notes on Page 20, Section 12
before removing or replacing parts.

Burner Components

All serviceable burner parts are accessed by the
door on the side of the heater. Remove the four
sheetmetal screws.

15.1 Gas Valve

Remove the gas supply pipe at the heater inlet.

Disconnect
wire harness

Unplug
control
from
valve.

Remove

fixing

screw.

Replace in reverse order. Verify that the gas flow
direction of the valve is correct. Use a minimum
amount of gas seal on the thread joint. Check that
all the joints are leak free. Reset gas valve. See
Page 17, Section 10.2.2.

IT IS IMPORTANT THAT ONLY THE CORRECT
GAS VALVE IS USED WHEN REPLACING THESE
CONTROLS.

Ignition
Control

Description Part Number

Gas Valve VK4105A 90033403
Ignition Control 90434010

26

15.2 Burner Compartment

Unscrew
Injectors

Manifold

SECTION 15: REMOVAL AND REPLACEMENT PARTS

15.2.1 Burner Injectors

Burner
Compartment
Cover

Viewing Port

Flame Probe
Ignition Electrode

Remove flexible
air duct from spigot.

Remove screws and
pull off burner cover.

Manifold

Remove manifold

screws and pull

out manifold.

The burner compartment is a sealed
compartment. Following any work,
re-seal the compartment with the gas
pipe rubber seal fully in place and all
screws fitted and tight.

Ensure gas tight fitting of injectors.
Ensure correct alignment with burners.
Ensure all pipe joints are gas tight.

Burners

Injectors

Manifold

Mounting

Bracket

MODEL CTCU-7 CTCU-11 CTCU-15 CTCU-22 CTCU-27 CTCU-32

Injector Quantity 2 3 4 5 6 7

Natural Gas (G20)

Injector size mm Ø 1.78 1.85 1.85 2.06 2.057 2.057

in Ø 0.070 0.073 0.073 0.081 0.081 0.081

Marking 504949464646

RG P/N 91930050 91930049 91930049 91930046 91930046 91930046

Natural Gas (G25)

Injector size mm Ø 1.99 2.06 2.06 2.26 2.261 2.261

in Ø 0.0785 0.081 0.081 0.089 0.089 0.089

Marking 474646434343

RG P/N 91930047 91930046 91930046 91930043 91930043 91930043

LPG Propane (G31) and LPG Butane (G30)

Injector size mm Ø 1.18 1.18 1.18 1.25 1.25 1.25

in Ø 0.0465 0.0465 0.0465 0.049 0.049 0.049

Marking 5656561.251.251.25

RG P/N 91930056 91930056 91930056 91930125 91930125 91930125

Gromet

Marking

27

COMBAT® CTCU UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

Burners

.120

(3 mm)

spark

gap

Ignition

Electrode

Flame
Probe

Burners

15.3 Ignition Electrode and Flame Probe

Limit

Thermostat

Fan

Thermostat

Ignition

Electrode

Flame

Probe

Burner Compartment

To replace the ignition electrode or flame probe, remove the electrical lead and screw.
Pull out from mounting. Refit in reverse ensuring that the gap to burner is as shown in the
front view of the burner compartment.

Description Part Number

Spark Electrode 90427411
Automatic Ignition Flame Probe 90439300
Burners 92000002
Fan Thermostat 90412102
Limit Thermostat 90412100

Front Views

28

15.4 Flue Fan Vertical Installation

Air Intake

Adapter

Air Intake Adapter
Intake &
Exhaust

Covers

Gasket

Mounting Plate

to Flue Fan

fixing screws

SECTION 15: REMOVAL AND REPLACEMENT PARTS

Intake &
Exhaust Covers

Mounting Plate

to Vent Box

fixing screws

Gaskets

Vent Box

To remove the fan, remove 3
screws securing the fan and
mounting plate to the vent box.

To remove the fan from the
mounting plate, remove the 4
screws.

Refit in reverse order.

To change the flue and air
intake orientation from back to
top, remove the fan and
mounting plate as above.

Remove intake and exhaust
covers from top of the heater.

Rotate the fan, mounting plate
and gasket clockwise until the
flue adapter lines up with the
top hole. Secure with 3 screws.

Remove the flexible duct from
the air intake adapter on the
back.

Flexible Duct

Remove the air intake adapter
from the back of the heater and
install in the appropriate hole on
top. Reconnect the flexible duct.

Install intake and exhaust
covers over the back holes.

Mounting Plate

to Vent Box

fixing screws

MODEL CTCU-7 CTCU-11 CTCU-15 CTCU-22 CTCU-27 CTCU-32

Flue Fan

RG P/N 90710470 90710470 90710470 90710460 90710460 90710460

Air Plate mm Ø 35 44 57 64 109.2 109.2

in Ø 1. 3 8 1. 7 5 2.25 2.50 4.3 4.3

RG P/ N 111112 10 111122 10 1111 321 0 11114 2 10 11115 210 11115210

Fasco

7021-11767

Fasco

7021-11768

Fasco

7021-11769

Ensure sealed joints.
Ensure mounting plate orifice is
clear and not obstructed.

To rin

S6818

Sit Controls

P1210838

Sit Controls

P1210838

IT IS IMPORTANT THAT ONLY THE CORRECT FLUE FAN SPECIFIED FOR EACH MODEL TYPE IS
USED WHEN REPLACING THESE ITEMS.

Carry out a commission after working on or changing a flue fan. See Page 18, Section 11.

29

COMBAT® CTCU UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

15.5 Pressure Switch

Pull off 3 way connector. Spring open plastic clips of
mounting cradle. Replace with correct type of
pressure switch for model. The pressure switches
are colour coded for each pressure setting.

WARNING

Carbon Monoxide Hazard

Use correct pressure switch specified for each model.

Use of incorrect pressure switch could cause unsafe

condition.

Failure to follow these instructions can
death or serious injury.

result in

Carry out a commission after working on or
changing a pressure switch. See Page 15, Section

10.

Pressure Switch CTCU-7 CTCU-11 CTCU-15 CTCU-22 CTCU-27 CTCU-32

RG P/N 90439812 90439812 90439812 90439803 90439803 90439803

Colour Code orange orange orange grey grey grey

Set Point mbar 0.45 0.45 0.45 1.02 1.02 1.02

in wc 0.18 0.18 0.18 0.41 .041 .041

30

SECTION 15: REMOVAL AND REPLACEMENT PARTS

15.6 Ignition Control

The control plugs onto the gas valve. Pull out 12 pin
electrical connection. Pull out ignition cable and
flame probe cable noting their positions

Release screw securing control to gas valve.
Refit in reverse. Ensure correct location of ignition

and flame probe cables. Ensure that the earth
connection is made directly to the earth point on the
gas valve.

15.7 CTCUA Axial Fan/Guard/Motor Assembly

The axial fan unit for the CTCUA heater is
supplied completely assembled and balanced.

15.7.1 Fan Removal and Replacement

Remove the screws

and washers.

15.8 Fan and Limit Thermostats

15.8.1 Removal and Replacement

1. Pull off the electrical connections to the
thermostat

2. Unscrew the two screws securing the
thermostat

3. Fit a new thermostat with two screws ensuring
that the correct temperature setting and type
are selected.
See Page 6, Section 4.3.

4. Reconnect the electrical connections and test
operation.

Description Part Number

Axial Fan CTCU-7 11111910
Axi al F an C TCU -11 111119 11
Axi al F an C TCU -15 111119 20
Axi al F an C TCU -22 111119 21
Axi al F an C TCU -27 /32 11111 92 2

15.7.2 To Replace the Fan Assembly

To replace the fan assembly, reverse the procedure
shown above. Fit rubber washers to the guard
mountings to reduce vibration.

• Check that the fan blades are free to rotate
before turning on the power to the fan.

• Strictly comply with the colour code of the fan
wires to ensure correct operation. See Page 14,
Section 9.3 wiring diagram.

• Use only genuine ROBERTS GORDON

®

replacement parts.

31

Attach this information to the wall near the ROBERTS GORDON® heater

®

Read the installation, Commissioning, Operation and Service Manual thoroughly before installation, operation or service.

OPERATING INSTRUCTIONS

1. STOP! Read all safety instructions on this information sheet.

2. Open the manual gas valve in the heater supply line.

3. Turn on electric power to the heater.

4. Set the thermostat to desired setting (above ambient temperature).
The automatic starting sequence begins.
NOTE: Following long shutdown periods, the burner control may go to
to 'LOCKOUT' during the start sequence. Push the reset button to
recommence firing. Contact service department if 'LOCKOUT'
continues (see manual for details).

TO TURN OFF THE HEATER

1. Turn the thermostat/time switch to 'OFF'. The burner will turn 'OFF'
immediately, but fans will continue to cool heat exchanger until the fan
thermostat switches off.

IF THE HEATER WILL NOT OPERATE, TO ENSURE YOUR SAFETY,

FOLLOW THESE INSTRUCTIONS TO SHUT DOWN YOUR HEATER

1. Set the thermostat to off or the lowest setting.

2. Turn off electric power to the heater.

3. Turn off the manual gas valve in the heater supply line.

4. Call your registered installer/contractor qualified in the installation
and service of gas-fired heating equipment.

Installation Clearances

Roof Terminal

Roof Terminal

WARNING

Fire Hazard

Some objects can catch fire or explode when placed
close to heater.

Keep all flammable objects, liquids and vapors the
required clearances to combustibles away from heater.

Failure to follow these instructions can result in death,
injury or property damage.

Clearances to Combustibles

Air

Intake

15 cm

15 cm

50 cm** 10 cm

Wall

Terminal

Flue

25 cm

3 m

30 cm

3 m

2.5 - 3.5 m*

**80 cm is necessary to service heater*Heaters may be mounted at a higher level if destratification fans are installed.

Roberts-Gordon, LLC

1250 William Street
P.O. Box 44
Buffalo, NY 14240-0044 USA
Telephone: [phone]
Fax: [phone]
Toll Free: 800.828.7450

Installation Code and Annual Inspections: All installations and service of ROBERTS GORDON® products must be performed by a contractor qualified in the installation and service of products sold and supplied by Roberts-Gordon and conform to all
requirements set forth in the ROBERTS GORDON
that a qualified contractor annually inspect your ROBERTS GORDON

Further Information: Applications, engineering and detailed guidance on systems design, installation and product performance is available through ROBERTS GORDON
Please contact us for any further information you may require, including the Installation, Operation and Service Manual.

This product is not for residential use.

This document is intended to assist licensed professionals in the exercise of their professional judgement.

© 2006 Roberts-Gordon, LLC All rights reserved. No part of this work covered by the copyrights herein may be reproduced or copied in any form or by any means  graphic, electronic, or mechanical, including photocopying, recording, taping, or information storage
and

www.rg-inc.com Printed in U.S.A.

retrieval systems  without written permission of Roberts-Gordon, LLC.

Roberts-Gordon Europe Limited

Oxford Street
Bilston, West Midlands WV14 7EG UK
Telephone: [phone]
Fax: [phone]

®

manuals and all applicable governmental authorities pertaining to the installation, service and operation of the equipment. To help facilitate optimum performance and safety, Roberts-Gordon recommends

®

products and perform service where necessary, using only ROBERTS GORDON® replacement parts.

Service Telephone: [phone]
Service Fax: [phone]
E-mail: [e-mail]
E-mail: [e-mail]

®

representatives.