Roberts Gorden Caribe CGTH Series User manual

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
vapors the minimum required safe
distances 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 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.
Roberts-Gordon LLC
1250 William Street
P. O . B o x 4 4
Buffalo, New York 14240-0044
Telephone: [phone]
Fax: [phone]
Toll Free: 800.828.7450
www.robertsgordon.com
© 2018 Roberts-Gordon LLC
CGTH-30
CGTH-40
CGTH-50
In-field conversions are only
supported for CGTH series
models built after November 6, 1998.
See Page 3, Section 2.4 for details.
P/N 280100NA Rev. E 09/18
Caribe®
Fuel Conversion
Kit Instructions

© 2018
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.
TABLE OF CONTENTS
SECTION 1: Heater Safety...................................................... 1
1.1 Manpower Requirements.............................................1
1.2 Safety Labels and Their Placement.............................1
1.3 California Proposition 65 ............................................. 1
SECTION 2: Installer Responsibility ..................................... 4
2.1 Thermostat Tag............................................................ 4
2.2 Corrosive Chemicals.................................................... 4
2.3 National Standards and Applicable Codes .................. 4
2.4 Identification of Convertible Heaters............................ 5
SECTION 3: For Natural to Propane Conversions Only ...... 6
3.1 Contents of Fuel Conversion Kits
(Natural to Propane) .................................................... 6
SECTION 4: For Propane to Natural Conversions Only ...... 7
4.1 Contents of Fuel Conversion Kits
(Propane to Natural) .................................................... 7
SECTION 5: Fuel Conversion Instructions ........................... 8
SECTION 6: Critical Considerations ................................... 16
6.1 Thermostat Tag.......................................................... 16
SECTION 7: Operation.......................................................... 18
7.1 Sequence of Operation.............................................. 18
7.2 Testing ....................................................................... 18
SECTION 8: Troubleshooting............................................... 20
8.1 General ...................................................................... 21
SECTION 9: Maintenance..................................................... 25
9.1 Pre-Season Maintenance and Annual Inspection...... 25
SECTION 10: The ROBERTS GORDON®CARIBE®
Warranty ......................................................... 27
Printed in U.S.A.

SECTION 1: HEATER S AFETY
1
SECTION 1: HEATER SAFETY
Yo ur Safety is Important to Us!
This symbol is used throughout
the manual to notify youof possi-
ble fire, electrical or burn hazards.
Please pay special attention when
reading and following the warn-
ings in these sections.
Installation, service and annual
inspection of heater must be done by a contractor
qualified in the installation and service of gas-fired
heating equipment.
Read this manual carefully before installation, opera-
tion or service of this equipment.
Due to the nature of gas conversions, it is important
youuse the correct conversion kit for the heater
model and gas youare converting to. Use only genu-
ine ROBERTS GORDON®conversion kits.
This heater is designed for heating residential and
nonresidential indoor spaces. Do not install in resi-
dential living and sleeping areas or basements.
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.
Protective gear is to be worn during installation,
operation and service. Thin sheet metal parts, includ-
ing the aluminum reflector portion of the heater and
the various venting components, have sharp edges.
To p r event injury, the use of work gloves is recom-
mended. The use of gloves will also prevent the
transfer of body oils from the hands to the surface of
the reflector.
Before installation, check that the local distribution
conditions, nature of gas and pressure, and adjust-
ment of the appliance are compatible.
This heater must be applied and operated under the
general concepts of reasonable use and installed
using best building practices.
This appliance is not intended for use by persons
(including children) with reduced physical, sensory or
mental capabilities, or lack of experience and knowl-
edge, unless they have been given supervision or
instruction concerning use of the appliance by a per-
son responsible for their safety. Children should be
supervised to ensure that they do no play with the
appliance.
For additional copies of the Installation, Operation
and Service Manual, please contact Roberts-Gordon
LLC.
1.1 Manpower Requirements
To p re vent personal injury and damage to the heater,
two persons will be required to remove the heater
from the carton. Both ends of the heater should be
lifted from the carton at the same time. The burner
should be lifted by gripping the bottom. The reflector
of the heater should be lifted using the hanger.
1.2 Safety Labels and Their Placement
Product safety signs or labels should be replaced by
the product user when they are no longer legible.
Please contact Roberts-Gordon LLC or your ROB-
ERTS GORDON®independent distributor to obtain
replacement signs or labels. See Page 2, Figure 1
through Page 3, Figure 2.
1.3 California Proposition 65
In accordance with California Proposition 65 require-
ments, a warning label must be placed in a highly
visible location on the outside of the equipment (i.e.,
near equipment’s serial plate). See label placement
drawing on Page 2, Figure 1 for label location. Avoid
placing label on areas with extreme heat, cold, corro-
sive chemicals or other elements. To order additional
labels, please contact Roberts-Gordon LLC or your
ROBERTS GORDON®independent distributor.

CGTH-SERIES FUEL CONVERSION INSTRUCTIONS
2
FIGURE 1: Bottom and Side Panel Label Placement
Side Panel Operating Instruction Label
Logo Label
Bottom Panel
Clearances to
Combustibles Label
Description Part Number
Logo Label 91037702
Operating Instruction Label 91037100
Clearances to Combustibles Label 91037800

SECTION 1: HEATER S AFETY
3
FIGURE 2: Control Side and Back Panel Label Placement
Description Part Number
Shock Hazard Label 91037901
Wiring Diagram Label 91037600
Fire Hazard Label 91037900
Cord Shock Hazard Label 91037500
Thermostat Connection Label 91037902
Carbon Monoxide Hazard label 91037300
Proposition 65 Warning Label 91070016

CGTH-SERIES FUEL CONVERSION INSTRUCTIONS
4
SECTION 2: INSTALLER RESPONSIBILITY
The installer is responsible for the following:
• To install the heater, as well as the gas and electri-
cal supplies, in accordance with applicable specifi-
cations and codes. Roberts-Gordon LLC
recommends the installer contact a local Building
Inspector or Fire Marshal for guidance.
• To use the information given in a layout drawing
and in the manual together with the cited codes
and regulations to perform the installation.
• To install the heater in accordance with the
clearances to combustibles.
• To furnish all needed materials not furnished as
standard equipment.
• To plan location of supports.
• To provide access to burners for servicing on all
sides for burner removal.
• To provide the owner with a copy of this installa-
tion, operation and service manual.
• To never use heater as support for a ladder or
other access equipment and never hang or sus-
pend anything from heater.
•Toensure there is adequate air circulation around
the heater and to supply air for combustion, venti-
lation and distribution in accordance with local
codes.
• To safely and adequately install heater using
materials with a minimal working load of 75 lbs
(33 kg).
• To ensure the heater is placed in a approved
application.
•
2.1 Thermostat Tag
A laminated thermostat tag is available for the heater
as a permanent reminder of the safety instructions
and the importance of the required clearances to
combustibles. Please contact Roberts-Gordon LLC
or your ROBERTS GORDON®independent distribu-
tor to obtain the thermostat tag. See Page 16, Sec-
tion 6.1 for details. Affix the tag by peeling off the
backing of the adhesive strips on the rear surface
and position the tag underneath the thermostat on a
wall near the heater.
2.2 Corrosive Chemicals
Roberts-Gordon LLC 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 premises.
* Halogenated Hydrocarbons are a family of chemical
compounds characterized by the presence of halo-
gen elements (fluorine, chlorine, bromine, etc.).
These compounds are frequently used in refriger-
ants, cleaning agents, solvents, etc. If these com-
pounds enter the air supply of the burner, the life
span of the heater components will be greatly
reduced. An outside air supply must be provided to
the burners whenever the presence of these com-
pounds is suspected. 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 the applicable standards 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.
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.

SECTION 2: INSTALLER RESPONSIBILITY
5
2.4 Identification of Convertible Heaters
In-field conversions are only supported for CGTH-
Series models built after November 6th,1998. For
units built earlier, contact Roberts-Gordon LLC or
your local ROBERTS GORDON®independent distrib-
utor. The date of manufacture is available from the
serial number on the silver data rating label. The
serial number key is as follows:
9811-080-050-0006
Where 9811 indicates the month and year of manu-
facture; i.e. November 1998
Where 080 is a reference to the CGTH product line.
Where 050 indicates the rate; i.e. 50,000 Btu/h.
Where 0006 indicates the number of manufacture;
i.e. the 6th burner of this model and rate built in
November 1998.
The serial number on the label data must indicate a
number of manufacture greater than the list below:
Model Original Gas Type Serial Number
CGTH-30 NG 9811-080-030-0003
CGTH-30 LP 9811-080-030-0004
CGTH-40 NG 9811-080-040-0002
CGTH-40 LP 9811-080-040-0003
CGTH-50 NG 9811-080-050-0008
CGTH-50 LP 9811-080-050-0006

CGTH-SERIES FUEL CONVERSION INSTRUCTIONS
6
SECTION 3: FOR NATURAL TO PROPANE CONVERSIONS ONLY
FIGURE 3: Conversion Kit Regulator Installation in Valve (Natural to Propane)
3.1 Contents of Fuel Conversion Kits (Natural to Propane)
All kits include this manual and the CGTH-series Installation, Operation and Service Manual.
Gas Conversion Label: P/N 91039400
Orifice: P/N (see Table below)
Door Gasket: P/N 08115100
Spring Kit (blue): P/N 90034400
LP
REG
10.5"
Setscrew P/N 91118009
Kit Number Model Gas Conver-
sion Label
Spring(Blue)
Kit, NG to LP
Orifice Door
Gasket
Setscrew
CGTH030NP CGTH-30 91039400 90034400 91910452 08115100 91118009
CGTH040NP CGTH-40 91039400 90034400 91910473 08115100 91118009
CGTH050NP CGTH-50 91039400 90034400 91910446 08115100 91118009

SECTION 4: FOR PROPANE TO NATURAL CONVERSIONS ONLY
7
SECTION 4: FOR PROPANE TO NATURAL CONVERSIONS ONLY
FIGURE 4: Conversion Kit Regulator Installation in Valve (Propane to Natural)
4.1 Contents of Fuel Conversion Kits (Propane to Natural)
All kits include this manual and the CGTH-series Installation, Operation and Service Manual.
Gas Conversion Label: P/N 91039400
Orifice: P/N (see Table below)
Spring Kit (green): P/N 90034401
Setscrew P/N 91118009
NG
REG
3.5"
Door Gasket: P/N 08115100
Kit Number Model Gas Conver-
sion Label
Spring(Green)
Kit, LP to NG
Orifice Door
Gasket
Setscrew
CGTH030PN CGTH-30 91039400 90034401 91910436 08115100 91118009
CGTH040PN CGTH-40 91039400 90034401 91910490 08115100 91118009
CGTH050PN CGTH-50 91039400 90034401 91910428 08115100 91118009

CGTH-SERIES FUEL CONVERSION INSTRUCTIONS
8
SECTION 5: FUEL CONVERSION INSTRUCTIONS
Step 5.1 Disable Burner
1. Leaving burner in place, turn off gas supply
valve.
2. Unplug heater from power receptacle.
FIGURE 5: Burner Assembly Overview
Cut/Pinch Hazard
Wear protective gear
during installation,
operation and service.
Edges are sharp.
WARNING
Failure to follow these instructions can result in death, electric shock, injury or property damage.
Burn Hazard
Allow heater to cool
before service.
Tubing may still be hot
after operation.
Explosion Hazard
Turn off gas supply to
heater before service.
DANGER
Electrical Shock Hazard
Disconnect electric
before service.
Replace door before
operating.
Heater must be
connected to a properly
grounded electrical
source.
Front Fixed Hanger (Ref)
Rear Movable Hanger (Ref)
Bolt
Heat Exchanger Flange
Flange Gasket
Heat Exchanger Tube
Burner Access
Cover Plate
Control Box Door
Burner Box Reflector
(shown removed for clarity)

SECTION 5: FUEL CONVERSION INSTRUCTIONS
9
FIGURE 6: Burner, Side View (Internal Assembly)
Step 5.2 Burner Cup Assembly Removal
1. R e m o ve control box door by removing (4) four
Phillips head screws.
2. Remove burner access cover plate by removing
(8) eight Phillips head screws. Remove and dis-
card the gasket on rear surface of cover plate.
3. Unplug ignition lead and sense wire from elec-
trodes.
4. Using an allen wrench, carefully remove the set-
screwfrom the burner cup. The setscrewis a
small part, be careful not to lose it.
5. Slide the burner cup forward into the heat
exchanger tube to access the orifice, be careful
not to drop the burner cup into the tube.
Ignition Lead
Burner Cup
Setscrew
Sense Wire and
Flame Sense
Electrode
(Behind Ignition Lead)
Electrodes

CGTH-SERIES FUEL CONVERSION INSTRUCTIONS
10
FIGURE 7: Burner, Side View (Internal Assembly) for Step 5.3
Table 1: Orifice Part Numbers
Step 5.3 Regulator Replacement
1. Using a 1/2" wrench, remove and discard the
orifice from the orifice holder adapter on which
the burner cup mounts. NOTE: Before installing
the neworifice, verify that the orifice supplied
with the kit is for the appropriate heater model
and gas being converted to. The size in the table
above should correspond to the size stamped
on the surface of the orifice. If youdo not have
the appropriate orifice, immediately contact Rob-
erts-Gordon LLC.
2. Install orifice supplied with this kit into the orifice
holder adapter.
3. Tighten orifice in place with wrench but do not
overtighten. (15 in-lbs max)
Gas Val e
Burner Box
Pipe Nipple
Orifice Holder
Adapter
Orifice Part Numbers
Natural to Propane Propane to Natural
Model BTU/hr Size Part Number Size Part Number
CGTH-30 30,000 #52 91910452 #36 91910436
CGTH-40 40,000 1.8 mm 91910473 1/8” 91910490
CGTH-50 50,000 #46 91910447 #28 91910428

SECTION 5: FUEL CONVERSION INSTRUCTIONS
11
WARNING
Explosion Hazard
Leak test all components of gas piping
before operation.
Gas can leak if piping is not installed
properly.
Do not high pressure test gas piping with
heater connected.
Failure to follow these instructions can result
in death, injury or property damage.

CGTH-SERIES FUEL CONVERSION INSTRUCTIONS
12
FIGURE 8: Burner, Top View (Internal Assembly) for Step 5.4
Step 5.4 Adjust Regulator
1. R e m o ve cap from gas valve/regulator by insert-
ing flat blade screwdriver through hole in top of
control box.
2. Turn regulator adjustment screwcounterclock-
wise and remove. Do not discard adjustment
screw.
3. Remove and discard spring from regulator.
NOTE: Before installing the newspring, verify
that the spring supplied with the kit is for the
appropriate heater model and gas being con-
verted to. For conversion to Propane, the spring
is BLUE. For conversion to Natural Gas, the
spring is GREEN. If youdo not have the appro-
priate spring, immediately contact Roberts-Gor-
don LLC.
4. Install spring supplied with this kit into regulator.
5. Reinstall regulator adjustment screw. Turn
adjustment screw(5) five full turns in a clock-
wise direction.
6. Install the round label, supplied with the regula-
tor spring in a conspicuous location on gas
valve/regulator as shown on Page 12, Figure 8.
Regulator Adjustment Screw

SECTION 5: FUEL CONVERSION INSTRUCTIONS
13
Step 5.5 Reinstall Burner
1. Reinstall burner cup to its original position;
replace setscrew.
2. Reinstall burner access cover plate using the
newgasket supplied with the fuel conversion kit.
Secure burner access cover plate to the burner
box with (8) eight Phillips head screws.
Step 5.6 Gas Pressure Checks
1. R e m o ve test plug and connect a manometer to
the test port connection as shown on Page 14,
Figure 9.
2. Plug in burner power supply cord.
3. Turn up thermostat to call for heat.
4. When the burner lights, set the manifold gas
pressure by adjusting the screwon top of the
gas valve/regulator. Natural Gas must be
adjusted to 3.5" wc; Propane must be adjusted
to 10.5" wc. Clockwise rotation of the adjustment
screwincreases setting, counterclockwise rota-
tion will decrease setting.
5. Turn thermostat down.
6. Disconnect burner power supply cord.
7. Disconnect manometer from the test port;
replace test plug on the regulator.
Replace control box door. Secure the control box
door to the burner box with (4) four Phillips head
screws.
WARNING
Carbon Monoxide Hazard
Heaters must be exhausted outside.
Use materials supplied.
This heater needs fresh air for safe operation
and must be installed so there are provisions
for adequate combustion and ventilation air.
Failure to follow these instructions can result
in death or injury.
DANGER
Electrical Shock Hazard
Plug heater into grounded three-prong ceiling
receptacle.
Do not cut or remove the grounding prong
from this plug.
Do not use with an extension cord.
Failure to follow these instructions can result
in death or electrical shock.

CGTH-SERIES FUEL CONVERSION INSTRUCTIONS
14
FIGURE 9: Manometer Reading
DANGER
Electrical Shock Hazard
Disconnect electric before service.
Appliance must be properly grounded.
Failure to follow these instructions can result
in death or electrical shock.

SECTION 5: FUEL CONVERSION INSTRUCTIONS
15
FIGURE 10: Label P/N 91039400
Step 5.7 Burner Conversion Label Information
1. Print the requested information in the fields of
the burner conversion label as shown in Figure
10, above.
Step 5.8Attach Burner Conversion Label
1. Attach the small yellowgas label (included in
conversion kit) to the gas valve. Attach the con-
version label (P/N 91039400) to the side of the
burner housing top. See Page 9, Figure 6.
2. Replace the burner housing door.
FIGURE 11: Label Placement
Enter Data for Natural to Propane Conversions Enter Data for Propane to Natural Conversions
Model Propane Orifice Size Model Natural Orifice Size
CGTH-30 #52 CGTH-30 #36
CGTH-40 1.8 mm CGTH-40 1/8”
CGTH-50 #46 CGTH-50 #28
Burner Box
A ix Gas Conversion Label Here
Data Plate
Fire Warning Label
Shock Hazard Label

CGTH-SERIES FUEL CONVERSION INSTRUCTIONS
16
SECTION 6: CRITICAL CONSIDERATIONS
In all situations, the minimum required safe distances
from combustibles must be maintained. Combusti-
bles are materials which may catch fire and include
many common items such as wood, paper, rubber,
fabrics, etc. Combustible materials such as those
noted, and any other combustible materials, must not
be placed closer to any base or side of the CGTH-
series heater than the distances noted in the dia-
grams on the following page.
Safe distances from combustibles are the required
distances that combustible objects must be away
from the heater to prevent serious fire hazards. Com-
bustibles are materials that may catch on fire and
include common items such as wood, paper, rubber,
fabric, etc. Maintain clearances to combustibles at
all times for safety.
Clearances for all heater models are located on the
burner of the heater and on Page 17, Figure 12
through Page 17, Figure 13 in this manual. Check the
clearances on each burner for the model heater
being installed to make sure the product is suitable
for your application and the clearances are main-
tained. Read and followthe safety guidelines below:
• Keep gasoline or other combustible materials
including flammable objects, liquids, dust or
vapors away from this heater or any other appli-
ance.
• The stated clearances to combustibles represents
a surface temperature of 90° F (50°C) above room
temperature. Building materials with a lowheat tol-
erance (such as plastics, vinyl siding, canvas, tri-
ply, etc) may be subject to degradation at lower
temperatures. It is the installer’s responsibility to
assure that adjacent materials are protected from
degradation.
• Maintain clearances from heat sensitive
equipment and workstations.
• Maintain clearances from vehicles parked below
the heater.
• Maintain clearances from swinging and overhead
doors, overhead cranes, vehicle lifts, partitions,
storage racks, hoists, building construction, etc.
• In locations used for the storage of combustible
materials, signs must be posted to specify the
maximum permissible stacking height to maintain
required clearances from the heater to the com-
bustibles. Signs must be posted adjacent to the
heater thermostat. In the absence of a thermostat,
signs must be posted in a conspicuous
location.
• Consult local Fire Marshal, Fire Insurance Carrier
or other authorities for approval of proposed instal-
lation when there is a possibility of exposure to
combustible airborne materials or vapors.
• Hang heater in accordance to the minimum sus-
pension requirements.
• If the radiant tubes must pass through the building
structure, be sure that adequate sleeving and fire
stop is installed to prevent scorching and/or fire
hazard.
6.1 Thermostat Tag
For owner safety, a thermostat tag is supplied with
the CGTH-series as a permanent reminder of the
importance of maintaining the required safe dis-
WARNING
Fire Hazard
Keep all flammable objects, liquids and
vapors the minimum required safe distances
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
Burn Hazard
Keep all persons, especially children, away
from heater.
Do not touch any part of the heater.
Heater is very hot.
Failure to follow these instructions can result
in death, injury or property damage.