Roberts Gorden UHX 100 Series Guide

Installation, Operation
& Service Manual
Models UHD[X][S]
75, 100, 125
P/N 113000NA 10/12 Rev C
UHD-Series
Tubular Duct Furnace
(Low Profile Range)
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 clear-
ances 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 serviceman with necessary information.
Roberts-Gordon LLC
1250 William Street
P.O. Box 44
Buffalo, New York 14240-0044
Telephone: [phone]
Fax: [phone]
Toll Free: 800.828.7450
www.robertsgordon.com
www.rg-inc.com
© 2012 Roberts-Gordon LLC
Combat®

P/N 113000FC 10/12 Rev C
AVERTISSEMENT
POUR VOTRE SECURITE
Si vous sentez une odeur de gaz:
1. Ouvrez les fenêtres.
2. N’essayez PAS d’allumer un appareil.
3. N’utilisez PAS d’interrupteurs
électriques.
4. N’utilisez PAS de téléphone dans votre
bâtiment.
5. Eteignez toute flamme nue.
6. Quittez le bâtiment.
7. Après avoir quitté le bâtiment, appelez
immédiatement votre fournisseur local
de gaz.
Suivez les instructions du fournisseur
de gaz.
8. Si vous ne pouvez pas joindre votre
fournisseur de gaz, appelez le service
d’incendie.
Risque d’incendie
Garder tous les objets, liquides ou vapeurs
inflammables à la distance minimale de
l’unité de chauffage requise avec les
matériaux combustibles.
Certains objets prendront feu ou exploseront
s’ils sont placés à proximité de l’unité de
chauffage.
Le non respect de ces instructions peut
entraîner la mort, des blessures corporelles
ou des dommages matériels.
© 2012 Roberts-Gordon LLC
AVERTISSEMENT
L’installation doit être effectuée par un entrepreneur
qualifié dans l'installation et l'entretien d'appareils de
chauffage au gaz ou par votre fournisseur de gaz.
L’installation, le réglage, la modification, la réparation ou
la maintenance inadapté peut entraîner la mort, des
blessures ou des dommages matériels. Lire attentivement
le manuel d'installation, d'utilisation et d'entretien avant
d’installer ou de réparer cet équipement.
Installateur
Veuillez prendre le temps de lire et de comprendre ces
instructions avant toute installation. L’installateur doit
donner un exemplaire de ce manuel au propriétaire.
Propriétaire
Garder ce manuel dans un endroit sûr pour fournir les
informations nécessaires au personnel d’entretien.
Roberts-Gordon LLC
1250 William Street
P.O. Box 44
Buffalo, New York 14240-0044
Téléphone: +1.716.852.4400
Fax: [phone]
Numéro sans fraís: 800.828.7450
www.robertsgordon.com
www.rg-inc.com
Manuel d’installation,
d’operation, et de service
Modèles UHD[X][S]
75, 100, 125
UHD-Series
Appareil de chauffage conduit à
échangeur tubulaire
(Gamme compacte)
Combat®

© 2012
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 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 Wall Tag ....................................................................... 4
2.2 Corrosive Chemicals.................................................... 4
2.3 National Standards and Applicable Codes .................. 4
SECTION 3: Critical Considerations .....................................5
3.1 Basic Information ......................................................... 5
3.2 Manufactured Units...................................................... 5
3.3 Location and Suspension ............................................ 5
3.4 Minimum Required Installation Clearances ................. 5
3.5 Ventilation .................................................................... 5
3.6 Gas Supply .................................................................. 5
3.7 Electrical Supply .......................................................... 5
3.8 Vent.............................................................................. 5
SECTION 4: Clearances to Combustibles.............................6
4.1 Required Clearances to Combustibles......................... 6
4.2 Clearances to Combustibles ........................................ 6
SECTION 5: National Standards and Applicable Codes .....7
5.1 Gas Codes...................................................................7
5.2 Aircraft Hangars ........................................................... 7
5.3 Parking Structures and Repair Garages ...................... 7
5.4 Electrical ...................................................................... 7
5.5 Venting......................................................................... 7
5.6 High Altitude ................................................................ 8
SECTION 6: Duct Heater Installation..................................... 9
6.1 General ........................................................................ 9
6.2 Shelf Mounting and Suspension ................................ 10
6.3 Wall Mounting ............................................................ 10
SECTION 7: Venting.............................................................. 12
7.1 Changing Vent and Air Intake Orientation .................. 12
7. 2 Venting ....................................................................... 12
7. 3 Vent Installation .......................................................... 12
7.4 Unvented Operation ................................................... 13
7.5 Horizontal Venting ...................................................... 13
7. 6 Vertical Venting........................................................... 13
7.7 Length Requirements ................................................. 13
7. 8 Vent Material............................................................... 14
7.9 Replacing an Existing Heater in a Venting System..... 14
SECTION 8: Air Supply......................................................... 18
8.1 Separated Combustion Installation ............................ 18
8.2 Unvented Installation ................................................. 18
8.3 Building Ventilation .................................................... 18
8.4 Outside Combustion Air Supply................................. 18
SECTION 9: Gas Piping........................................................ 19
9.1 Connections............................................................... 19
SECTION 10: Wiring..............................................................21
10.1 Positioning Thermostats ..........................................21
10.2 LowVoltage Thermostat with One Heater................21
10.3 UHD[X][S] Series Internal Wiring Diagram...............22
10.4 UHD[X][S] Series Ladder Wiring Diagram................23
10.5 Electrical Connection to the Heater..........................24
SECTION 11: Operation and Maintenance ..........................25
11.1 Pre-Start-Up Checks.................................................25
11.2 Begin Start-Up ..........................................................25
11.3 Complete Start-Up ....................................................27
SECTION 12: User Instructions............................................28
12.1 Heater Operation......................................................28
12.2 Common User Controls............................................28
12.3 Lighting Instructions .................................................29
12.4 Simple Troubleshooting ............................................29
SECTION 13: Servicing.........................................................30
13.1 Servicing Instructions...............................................30
13.2 Burner Maintenance.................................................30
13.3 Heat Exchanger Maintenance..................................30
13.4 Gas Valve Maintenance ...........................................30
13.5 Flue Blower ..............................................................30
13.6 Venting and Air Intake Pipe ......................................30
13.7 Maintenance Checklist .............................................31
SECTION 14: Troubleshooting.............................................33
14.1 General ....................................................................34
14.2 Troubleshooting For Automatic Ignition Burner
Systems ...................................................................35
14.3 Troubleshooting for Flame Supervision System .......36
14.4 Troubleshooting for Gas Valves................................37
14.5 Troubleshooting for Flue Blower ...............................37
SECTION 15: Replacement Parts.........................................38
15.1 Gas Valve .................................................................38
15.2 Burner Compartment ...............................................39
15.3 Ignition Electrode and Flame Probe .........................40
15.4 Heat Exchanger .......................................................40
15.5 Flue Blower Vertical Installation ...............................41
15.6 Pressure Switch........................................................42
15.7 Ignition Control .........................................................42
15.8 Limit Switches ..........................................................42
SECTION 16: Specifications.................................................43
16.1 Dimension Data........................................................43
16.2 General Technical Data Table ..................................44
16.3 Technical Data Table ................................................44
SECTION 17: ROBERTS GORDON®COMBAT®
UHD-Series Warranty.....................................46

TABLE OF FIGURES
Figure 1: UHD [X][S] 75 Label Placement ................................ 2
Figure 2: UHD [X][S] 100-125 Label Placement........................ 3
Figure 3: Clearances to Combustibles ...................................... 6
Figure 4: Air FlowDirection ....................................................... 9
Figure 5: Suspension Methods ............................................... 10
Figure 6: Shelf-Mounting Methods.......................................... 11
Figure 7: Wall Shelf Mounting and Suspension ...................... 11
Figure 8: Vent and Roof Detail ................................................ 14
Figure 9: Standard Vented Heater - Vertical and Horizontal
Vent Termination...................................................... 15
Figure 10: Standard Vented Heater - Common Vertical
Vent Termination...................................................... 15
Figure 11: Separated Combustion Heater - Vertical and
Horizontal Vent Termination..................................... 16
Figure 12: Concentric Vent Box............................................... 16
Figure 13: Concentric Vertical and Horizontal Vent
Termination - Separated Combustion Heater .......... 17
Figure 14: Gas Connection ..................................................... 20
Figure 15: Automatic Burner Control Sequence...................... 26
Figure 16: Gas Valve for Models UDH[X][S] 75 – 125............. 26
Figure 17: Manual Reset Limit Switch ..................................... 29
Figure 18: LED Diagnostic Codes........................................... 29

SECTION 1: HEATER SAFETY
1 of 47
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, at a
minimum, 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,
operation or service of this equipment.
Heaters are not approved for residential
installations. 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,
including 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.
This heater must be applied and operated under the
general concepts of reasonable use and installed
using the 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
knowledge, unless they have been given
supervision or instruction concerning use of the
appliance by a person responsible for their safety.
Children should be supervised to ensure that they
do not play with the appliance.
For additional copies of the Installation, Operation
and Service Manual, please contact Roberts-
Gordon LLC.
1.1 M a n power Requirements
To prevent personal injury and damage to the
heater, two persons will be required for installation.
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
ROBERTS 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
requirements, 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
through Page 3, Figure 2 for label location. Avoid
placing label on areas with extreme heat, cold,
corrosive chemicals or other elements. To order
additional labels, please contact Roberts-Gordon
LLC or your ROBERTS GORDON®independent
distributor.

UHD LOW PROFILE DUCT FURNACE INSTALLATION OPERATION AND SERVICE MANUAL
2 of 47
Figure 1: UHD[X][S] 75 Label Placement
Description Part Number
Logo Label 91040030
Cut Hazard Label 91010430
Vent Length Label 91039505
Vent to Outdoors Label 91010427
Warning Label 91010429
Rating Plate Label 91039802
Installation Label 91010431
Instruction Location Label 91010433
Lighting Instruction Label 91010425
Venting Arrangement Label* 91010426
Manual Reset Switch Label 91010428
Proposition 65 Label 91070015
* For separated combustion units only

SECTION 1: HEATER SAFETY
3 of 47
Figure 2: UHD[X][S] 100-125 Label Placement
WARNING
Printedin the U.S.A./Imprimé aux Etats-Unis P/N91010429
www.rg-inc.com
©2006 Roberts-Gordon, LLC
Fire Hazard
Some objects can catch fire or explode when placed close
to heater.
Keep all flammable objects,liquids and vapors the
required clearancesto combustibles away from heater.
Refer to installation manual forclearances and proper
installation.
ATTENTION
Electrical Shock Hazard
Disconnect electrical power before servicing.
This appliance must be grounded.
Explosion Hazard
Connect fuel supply according to installation manual.
Improper installation can cause fuel leak.
Failure to follow these instructions can result in death,injury or property damage .
Le non-respect de ces instructions peut entraÎner de la mort,
des blessures ou des dégâts matériels.
Risque d'Incendie
Certains objets peuvent s'enflammer ou s'exploser quand
ils se trouvent prèsde l'appareil de chauffage.
Eloigner tout objet, liquide,ou vapeur inflammable de
l'appareil de chauffage.Les distances minimales de
dégagement par rapport aux matériaux combustibles
doivent être impérativementrespectées.
Reférer au manuel d'installation pour les distances de
dégagement et les instructions pour un installation
correct.
Risque de Choc Electrique
Débrancher le courant électrique avanttoute
intervention.
Cet appareil doit être mis à la terre.
Risque d'Explosion
Le service de gaz doit être connecté selon le manuel
d'installation.
Un installation incorrect peut causer une fuite de gaz.
Lighting and Operation Instructionslocated on the other side of this panel.
Les instructions d'allumage et d'operationsont situées à l'autre côté de
ce panneau.
P/N91010433
©2006 Roberts-Gordon, LLC www.rg-inc.com
Printedin U.S.A. / Imprimé aux Etats Unis
Logo Label Vent Length Label
WARNING
This heater must be installed in accordance with the manufacturer's
instructions and local codes. In the absence of local codes, follow
the National Fuel Gas Code, ANSI Z223.1 / NFPA 54 or the CAN/CSA-
B149 installation code.
Cet aérotherme doit être installé en accord avec les instructions du
fabricant et les régulations locaux. S'il n'y a pas des régulations locaux,
l'installation doit être en accord avec le Code National de Gaz de Carburant,
ANSI Z223.1 / NFPA 54 ou le Code d'Installation,CAN/CSA-B149.
© 2006 Roberts-Gordon, LLC P/N 91010431Rev Bwww.rg-inc.com
Printed in U.S.A./ Imprimé aux Etats Unis
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, modification, réglage ou maintenance incorrectes
peuvent provoquer de la mort, des blessures ou des dégâts
matériels. Liser attentivement le manuel d'installation,d'operations
et d'entretien avant l'installation ou l'entretien de cet équipment.
A. Thisappliance doesnot have a pilot. It isequipped with anignitiondevice which automatically lightsthe
burner. Do not try to light the burnerby hand.
B. BEFORE OPERATING smell all around the appliance area forgas. Be sure to smell next to the floorbecause
some gasisheavierthanairand will settle onthe floor.
WHAT TO DO IF YOU SMELL GAS:
• Do not try to light any appliance. • Do not touch any electric switch; do not use any phone inyour building.
• Immediately call your gassupplierfrom a neighbor'sphone. Follow the gassupplier'sinstructions.
• If youcannot reach your gassupplier, call the fire department.
C. Use only your hand to push inorturn the gascontrol knob. Neveruse tools. If the knob will not push inor
turn by hand, don't try to repairit, call a qualified service technician. Force orattempted repairmay result ina
fire orexplosion.
D. Do not use thisappliance if any part hasbeenunderwater. Immediately call a qualified service technicianto
inspect the appliance and to replace any part of the control system and any gascontrol which
hasbeenunderwater.
OPERATING INSTRUCTIONS
1. STOP! Read the safety informationabove onthislabel.
2. Set the thermostat to the lowest setting.
3. Turn off all electric powerto the appliance.
4. Thisappliance isequipped with anignitiondevice. Do not try to light the burnerby hand.
5. Remove control access panel.
6. Push ingascontrol knob slightly and turn clockwise to "OFF".
NOTE: Knob cannot be turned to "OFF" unless it ispushed inslightly.
Do not force.
7. Wait five (5) minutesto clearout any gas. Thensmell forgasincluding near
the floor. if yousmell gas, STOP! Follow "B" inthe safety informationabove
onthislabel. If youdon't smell gas, go to the next step.
8. Turn gascontrol knob counterclockwise to "ON".
9. Replace control access panel.
10. Turn onall electric powerto the appliance.
11. Set thermostat to desired setting.
12. If the appliance will not operate, follow the instructions "To TurnOff Gas
to Appliance" below onthislabel and call your service technicianor
gassupplier.
TO TURN OFF GAS APPLIANCE
1. Set the thermostat to lowest setting.
2. Turn off all electric powerto the appliance if service isto be performed.
3. Remove control access panel.
4. Push ingascontrol knob slightly and turn clockwise to"OFF".
Do not force.
5. Replace control access panel.
½PSI IN
OFF ON
A. Cet appareil ne comporte pasde veilleuse. Il est muni d'un dispositif d'allumage qui allume automatiquement
le brûleur. Ne tentez pasd'allumerle brûlermanuellement.
B. AVANT DE FAIREFONCTIONNER, reniflez tout autour de l'appareil pour décelerune odeur de gaz.
Reniflez prèsduplancher, carcertains gaz sont plus lourdsque l'airet peuvent s'accumulerauniveaudusol.
QUE FAIRE SI VOUS SENTEZ UNE ODEUR DE GAZ:
• Ne pastenterd'allumerd'appareil.
• Ne touchez à aucun interrupteur; ne pasvous servirdestéléphonesse trouvant dans le bâitment.
• Appelez immédiatement votre fournisseur de gaz depuisun voisin. Suivez lesinstructions de fournisseur.
• Si vous ne pouvez pasrejoindre le fournisseur, appelez le service desincendies.
C. Poussez outournez la manette d'admissiondugaz qu'à la main; ne jamaisutiliserd'outil. Si la manette reste
coincée, ne pastenterde la réparer; appelez un technicienqualifié. Le fait de forcerla manette oude la réparerpeut
déclencherune explosionouun incendie.
D. N'utilisez pascet appareil s'il a été plongé dans l'eau, même partiellement. Faitesinspecterl'appareil parun
technicienqualifié et remplacez toute commande qui ont été plongésdans l'eau.
INSTRUCTIONS DE MISE EN MARCHE
1. ARRÊTEZ! Lisez lesinstructions de sécurité sur la portionsupérieure de cette étiquette.
2. Appareil pourvud'un thermostat réglable oudestiné à être utilisé avec un tel dispositif:
Réglez le thermostat à la température la plus basse.
3. Appareil à alimentationélectrique externe: Coupez l'alimentationélectrique de l'appareil.
4. Fournirdesinstructions qui indiquent de ne pastenterd'allumerla veilleuse de façonmanuelle.
5. Si despanneaux oudespiècesde l'appareil doivent être retiréspour atteindre la commande d'admissiondugaz, desinstructions
doivent indiquerla marche à suivre.
6. Desinstructions, et une illustration, doivent être fourniespour la fermeture complète (positionOFF) durobinet de l'admissiondu
gaz. Lorsqu'une rotationest requise, lesmotset symbolessuivantsdoivent être utiliséspour indiquerle sens de la rotation.
sens horaire sens antihoraire
7. Attendre cinq (5) minutespour laisseréchappertout le gaz. Reniflez tout autour de l'appareil, y comprisprèsduplancher, pour déceler
une odeur de gaz. Si vous sentez une odeur de gaz, ARRÊTEZ! Passez à l'étape B des
instructions de sécurité sur la portionsupérieure de cette étiquette. S'il n'y a pasd'odeur de gaz,
passez à l'étape suivante.
8. Fournirdesinstructions pour l'ouverture (positionON) durobinet manuel de l'admissionde gaz.
9. Le caséchéant, fournirdesinstructions sur la réinstallationdespanneaux oupiècesd'accèsà la
commande d'admissionde gaz.
10. Le caséchéant: Mettez l'appareil sous tension.
11. Le caséchéant: Réglez le thermostat à la température désirée.
12. Fournirdesinstructions donnant lesmesuresà prendre si l'appareil ne fonctionne pasmême si
lesinstructions ci-dessus ont été respectéesainsi que l'énoncé suivant: Si l'appareil ne se met
pasenmarche, suivez lesinstructions intitulées"Comment couperl'admissionde gaz de
l'appareil" et appelez un technicienqualifié oule fournisseur de gaz. Le fabricant peut spécifier
un intervalle plus long.
COMMENT COUPER L'ADMISSION DE GAZ DE L'APPAREIL
1. Le caséchéant: Réglez le thermostat à la température la plus basse.
2. Le caséchéant: Coupez l'alimentationélectrique de l'appareil s'il faut procéderà l'entretien.
3. Le caséchéant, fournirdesinstructions sur la méthode à suivre pour atteindre la commande
d'admissiondugaz.
4. Fournirdesinstructions pour la fermeture complète (positionOFF) durobinet manuel de
l'admissiondugaz.
5. Le caséchéant, fournirdesinstructions sur la réinstallationdespanneaux d'accèsà la
commande d'admissionde gaz.
ForModels 30/45 / PourModèles 30/45
ForModels 60 - 400 / PourModèles 60 - 400
ON
OFF
Gas valve shown in
"OFF" position.
Le robinet de
l'admission du gaz
est en la position
OFF.
WARNING
Explosion Hazard
Read instructions completely before operating heater.
Failure to follow these instructions can result in death,
fire, explosion, injury or property damage.
Printed in the U.S.A/Impriméaux Etats-Unis. P/N91010425
www.rg-inc.com
© 2006 Roberts-Gordon, LLC
ATTENTION
FOR YOUR SAFETY, READ BEFORE OPERATING
Risque d'Explosion
Liser ces instructions complètement avant l'opération
de l'aerotherme.
Le non-respect de ces instructions peut entraîner du feu,
de l'explosion, du mort, des blessures ou des dommages.
Pour votre sécurité, liser ces instructions avant l'opération de cet appareil.
WARNING
Printed in the U.S.A./Impriméaux Etats-Unis P/N91010429
www.rg-inc.com
© 2006 Roberts-Gordon, LLC
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.
Refer to installation manual for clearances and proper
installation.
ATTENTION
Electrical Shock Hazard
Disconnect electrical power before servicing.
This appliance must be grounded.
Explosion Hazard
Connect fuel supply according to installation manual.
Improper installation can cause fuel leak.
Failure to follow these instructions can result in death, injury or property damage.
Le non-respect de ces instructions peut entraÎner de la mort,
des blessures ou des dégâts matériels.
Risque d'Incendie
Certains objets peuvent s'enflammer ou s'exploser quand
ils se trouvent près de l'appareil de chauffage.
Eloigner tout objet, liquide, ou vapeur inflammable de
l'appareil de chauffage. Les distances minimales de
dégagement par rapport aux matériaux combustibles
doivent être impérativement respectées.
Reférer au manuel d'installation pour les distances de
dégagement et les instructions pour un installation
correct.
Risque de Choc Electrique
Débrancher le courant électrique avant toute
intervention.
Cet appareil doit être mis à la terre.
Risque d'Explosion
Le service de gaz doit être connecté selon le manuel
d'installation.
Un installation incorrect peut causer une fuite de gaz.
Warning Label
Lighting Instructions
Label
Lighting and Operation Instructions located on the other side of this panel.
Les instructions d'allumage et d'operation sont situées à l'autre côté de
ce panneau.
P/N91010433
© 2006 Roberts-Gordon, LLC www.rg-inc.com
Printed in U.S.A./ Imprimé aux Etats Unis
Instruction Location
Label
FRONT VIEW BACK VIEW
ACCESS SIDE VIEW (OUTSIDE) ACCESS SIDE VIEW (INSIDE)
Combat®
by
Combat®
by
VENT TO OUTDOORS
DONNER VENT
A DEHORS
© 2006 Roberts-Gordon, LLC P/N 91010427
Printed in U.S.A. / Imprimé aux Etats Unis
WARNING
P/N91010430
Cut Hazard
Turnoff electrical supply before
maintenance.
Fancan star t automatically.
Failureto follow these
instructions can resultin serious
injury or property damage.
ATTENTION
Risque de Coupure
Couper l'alimentation
électrique
avant l'entretien.
Le ventilateur peut démarrer
automatiquement à tout
moment.
Le non-respect de ces
instructions peut entraîner
des blessures gravesou des
dommages.
©2006Rober ts-Gordon, LLC
Printedin U.S.A. / Imprimé aux Etats Unis
WARMAIRMODELS / Chauffages à l'airchaud Maximum Minimum
Models30-75 VentCombustion / Air Duct Length 25'(7.6m) 3'(1m)
Longeurtotale de l'évacuationde gaz ou l'alimentationen air pour les modèles 30 - 75
Models100-400 VentCombustion / Air DuctLength 40'(12.2m) 3 '(1 m)
Longeurtotale de l'évacuationde gaz ou l'alimentationen air pour les modèles 100 - 400
Ifusing vent lengths greater than 5'(1.5m), condensation will form in the vent pipe. Insulate the pipe to reduce
formationof condensate. For Category IV appliances, condensatetee and drain must be used.L’emploid’une
évacuationde gaz de plus de 5' (1.5m) provoquera la formation de condensation dans le tuyau d’évacuation
degaz. Isolez le tuyau pour réduirela formation de condensation. Pour les appareils en catégorieIV, un pièce
enT pour la condensation et un tuyau d'écoulement doivent être utilisés
SEEINSTALLATIONMANUAL FOR PARTS LIST,METHOD OF INSTALLATION AND FURTHERVENTING DETAILS.
VOIRLE MANUEL D’INSTALLATIONPOUR PLUS DE RENSEIGNEMENTS.
WARNING ATTENTION
VENTHEATER TO OUTDOORS / ECHAPPEMENT DU BRULEURA L'EXTERIEUR
VENT L ENG TH R EQUI REME NT /Exigence du Longeur de l'évacuation de Gaz
P/N91039505
Printedin U.S.A./Imprimé aux États-Unis
©2006 Roberts-Gordon, LLC www.rg-inc.com
CarbonMonoxide Hazard
Thisappliance requires a
specialventing system.
Heatersmust be installed
accordingto the installation
manual.
Failureto follow these
instructionscan result in
deathor injury.
Risqued'Oxyde de Carbone
Cetappareil doit avoir un
échappementspécial.
Lesaérothermes doivent être
installésselon le manuel
d'installation.
Lenon-respect de ces
consignespeut entraîner de la
mortou des blessures.
Vent to
Outdoors
Label
WARMAIR MODELS/ Chauffages à l'airchaud Maximum Minimum
Models 30-75 VentCombustion / Air Duct Length 25'(7.6m) 3'(1 m)
Longeur totale de l'évacuation de gaz ou l'alimentationen air pour les modèles 30 - 75
Models 100-400Vent Combustion /Air Duct Length 40'(12.2 m) 3'(1 m)
Longeur totale de l'évacuation de gaz ou l'alimentationen air pour les modèles 100 - 400
If using vent lengths greater than 5'(1.5 m), condensation will form in the vent pipe. Insulate the pipe to reduce
formation of condensate. For CategoryIV appliances, condensate tee and drain must be used. L’emploi d’une
évacuation de gaz de plus de 5' (1.5 m) provoquera la formation de condensation dans le tuyau d’évacuation
de gaz.Isolez le tuyau pour réduire la formation de condensation. Pour les appareils en catégorie IV,un pièce
en T pour la condensation et un tuyaud'écoulement doivent être utilisés
SEE INSTALLATION MANUAL FOR PARTS LIST,METHOD OF INSTALLATION AND FURTHERVENTING DETAILS.
VOIR LE MANUEL D’INSTALLATIONPOUR PLUS DE RENSEIGNEMENTS.
WARNING ATTENTION
VENT HEATERTO OUTDOORS / ECHAPPEMENT DU BRULEUR A L'EXTERIEUR
VEN T LE NGT H RE QUIR EMEN T / Exigence du Longeur de l'évacuation de Gaz
P/N91039505
Printed in U.S.A./Imprimé aux États-Unis
© 2006 Roberts-Gordon, LLC www.rg-inc.com
Carbon Monoxide Hazard
This appliance requires a
special venting system.
Heaters must be installed
according to the installation
manual.
Failure to follow these
instructions can result in
death or injury.
Risque d'Oxyde de Carbone
Cet appareil doit avoir un
échappement spécial.
Les aérothermes doivent être
installés selon le manuel
d'installation.
Le non-respect de ces
consignes peut entraîner de la
mort ou des blessures.
WARNING
P/N91010430
Cut Hazard
Turn off electrical supply before
maintenance.
Fan can start automatically.
Failure to follow these
instructions can result in serious
injury or property damage.
ATTENTION
Risque de Coupure
Couper l'alimentation
électrique
avant l'entretien.
Le ventilateur peut démarrer
automatiquement à tout
moment.
Le non-respect de ces
instructions peut entraîner
des blessures graves ou des
dommages.
© 2006 Roberts-Gordon, LLC
Printed in U.S.A./ Imprimé aux Etats Unis
Cut
Hazard
Label
A.Thisappliance doesnot have a pilot. It isequipped with anignitiondevice which automatically lightsthe
burner.Do not try to light the burnerby hand.
B.BEFORE OPERATING smell all around the appliance area forgas. Be sure to smell next to the floorbecause
somegasisheavierthanairand will settle onthe floor.
WHATTO DO IF YOU SMELL GAS:
•Do not try to light any appliance. • Do not touch any electric switch; do not use any phone inyour building.
•Immediately call your gassupplierfrom a neighbor'sphone. Follow the gassupplier'sinstructions.
•If youcannot reach your gassupplier, call the fire department.
C.Use only your hand to push inorturn the gascontrol knob. Neveruse tools. If the knob will not push inor
turnby hand, don't try to repairit, call a qualified service technician. Force orattempted repairmay result ina
fireorexplosion.
D.Do not use thisappliance if any part hasbeenunderwater. Immediately call a qualified service technicianto
inspectthe appliance and to replace any part of the control system and any gascontrol which
hasbeenunderwater.
OPERATINGINSTRUCTIONS
1.STOP! Read the safety informationabove onthislabel.
2.Set the thermostat to the lowest setting.
3.Turn off all electric powerto the appliance.
4.Thisappliance isequipped with anignitiondevice. Do not try to light the burnerby hand.
5.Remove control access panel.
6.Push ingascontrol knob slightly and turn clockwise to"OFF".
NOTE:Knob cannot be turned to "OFF" unless it ispushed inslightly.
Donot force.
7.Wait five (5) minutesto clearout any gas. Thensmell forgasincluding near
thefloor. if yousmell gas, STOP! Follow "B" inthe safety informationabove
onthislabel.If youdon't smell gas, go to the next step.
8.Turn gascontrol knob counterclockwise to "ON".
9.Replace control access panel.
10.Turn onall electric powerto the appliance.
11.Set thermostat to desired setting.
12.If the appliance will not operate, follow the instructions "To Turn Off Gas
toAppliance" below onthislabel and call your service technicianor
gassupplier.
TO TURN OFF GAS APPLIANCE
1.Set the thermostat to lowest setting.
2.Turn off all electric powerto the appliance if service isto be performed.
3.Remove control access panel.
4.Push ingascontrol knob slightly and turn clockwise to"OFF".
Do not force.
5.Replace control access panel.
½PSI IN
OFF ON
A.Cet appareil ne comporte pasde veilleuse. Il est muni d'un dispositif d'allumage qui allume automatiquement
lebrûleur. Ne tentez pasd'allumerle brûlermanuellement.
B.AVANT DE FAIRE FONCTIONNER, reniflez tout autour de l'appareil pour décelerune odeur de gaz.
Reniflezprèsduplancher, carcertains gaz sont plus lourdsque l'airet peuvent s'accumulerauniveaudusol.
QUEFAIRE SI VOUS SENTEZ UNE ODEUR DE GAZ:
•Ne pastenterd'allumerd'appareil.
•Ne touchez à aucun interrupteur; ne pasvous servirdestéléphonesse trouvant dans le bâitment.
•Appelez immédiatement votre fournisseur de gaz depuisun voisin. Suivez lesinstructions de fournisseur.
•Si vous ne pouvez pasrejoindre le fournisseur, appelez le service desincendies.
C.Poussez outournez la manette d'admissiondugaz qu'à la main; ne jamaisutiliserd'outil. Si la manette reste
coincée,ne pastenterde la réparer; appelez un technicienqualifié. Le fait de forcerla manette oude la réparerpeut
déclencheruneexplosionouun incendie.
D.N'utilisez pascet appareil s'il a été plongé dans l'eau, même partiellement. Faitesinspecterl'appareil parun
technicienqualifiéet remplacez toute commande qui ont été plongésdans l'eau.
INSTRUCTIONS DE MISE EN MARCHE
1.ARRÊTEZ! Lisez lesinstructions de sécurité sur la portionsupérieure de cette étiquette.
2.Appareil pourvud'un thermostat réglable oudestiné à être utilisé avec un tel dispositif:
Réglezle thermostat à la température la plus basse.
3.Appareil à alimentationélectrique externe: Coupez l'alimentationélectrique de l'appareil.
4.Fournirdesinstructions qui indiquent de ne pastenterd'allumerla veilleuse de façonmanuelle.
5.Si despanneaux oudespiècesde l'appareil doivent être retiréspour atteindre la commande d'admissiondugaz, desinstructions
doiventindiquerla marche à suivre.
6.Desinstructions, et une illustration, doivent être fourniespour la fermeture complète (positionOFF) durobinet de l'admissiondu
gaz.Lorsqu'une rotationest requise, lesmotset symbolessuivantsdoivent être utiliséspour indiquerle sens de la rotation.
senshoraire sens antihoraire
7.Attendre cinq (5) minutespour laisseréchappertout le gaz. Reniflez tout autour de l'appareil, y comprisprèsduplancher, pour déceler
uneodeur de gaz. Si vous sentez une odeur de gaz, ARRÊTEZ! Passez à l'étape B des
instructionsde sécurité sur la portionsupérieure de cette étiquette. S'il n'y a pasd'odeur de gaz,
passezà l'étape suivante.
8.Fournirdesinstructions pour l'ouverture (positionON) durobinet manuel de l'admissionde gaz.
9.Le caséchéant, fournirdesinstructions sur la réinstallationdespanneaux oupiècesd'accèsà la
commanded'admissionde gaz.
10.Le caséchéant: Mettez l'appareil sous tension.
11.Le caséchéant: Réglez le thermostat à la température désirée.
12.Fournirdesinstructions donnant lesmesuresà prendre si l'appareil ne fonctionne pasmême si
lesinstructionsci-dessus ont été respectéesainsi que l'énoncé suivant: Si l'appareil ne se met
pasenmarche,suivez lesinstructions intitulées"Comment couperl'admissionde gaz de
l'appareil"et appelez un technicienqualifié oule fournisseur de gaz. Le fabricant peut spécifier
unintervalle plus long.
COMMENTCOUPER L'ADMISSION DE GAZ DE L'APPAREIL
1.Le caséchéant: Réglez le thermostat à la température la plus basse.
2.Le caséchéant: Coupez l'alimentationélectrique de l'appareil s'il faut procéderà l'entretien.
3.Le caséchéant, fournirdesinstructions sur la méthode à suivre pour atteindre la commande
d'admissiondugaz.
4.Fournirdesinstructions pour la fermeture complète (positionOFF) durobinet manuel de
l'admissiondugaz.
5.Le caséchéant, fournirdesinstructions sur la réinstallationdespanneaux d'accèsà la
commanded'admissionde gaz.
ForModels30/45 / PourModèles 30/45
ForModels60 - 400 / PourModèles 60 - 400
ON
OFF
Gasvalve shown in
"OFF"position.
Lerobinet de
l'admissiondu gaz
esten la position
OFF.
WARNING
Explosion Hazard
Read instructions completely beforeoperating heater.
Failure to followthese instructions can result in death,
fire, explosion,injury or property damage.
Printedin the U.S.A/Imprimé aux Etats-Unis. P/N91010425
www.rg-inc.com
©2006 Roberts-Gordon, LLC
ATTENTION
FORYOUR SAFETY, READ BEFORE OPERATING
Risque d'Explosion
Liser ces instructions complètement avant l'opération
de l'aerotherme.
Le non-respect de ces instructions peut entraîner du feu,
de l'explosion, du mort, des blessuresou des dommages.
Pour votresécurité, liser ces instructions avant l'opération de cet appareil.
Venting Arrangement: Forseparated combustionunits, vent terminal and outside airintake must
be located inthe same pressure zone. Optional concentric vent kitsmay be used. See Installation,
Operationand Service Manual fordetailsand part numbers. Vent heaterthrough wall/roof of
minimum thickness 0", maximum thickness 18".
Arrangement pourVentilation: Pour lesaérothermesà combustionséparée, la conduite de
fumée et la prise d'airdoivent être situéesdans la même zone de pression. Onpeut utiliserle
système, concentrique optionel. Voirle manuel d'installation, de fonctionnement et d'entretien
pour lesdétailset lesréférencesde pièce. Ventilerl'aérotherme autravers d'un mur oud'un toit
avec une épaisseur minimum de 0" et une épaisseur maximum de 18".
*Venting Arrangement
Label
VentingArrangement: Forseparated combustionunits, vent terminal and outsideairintake must
be located inthe samepressure zone. Optional concentricvent kitsmay be used. See Installation,
OperationandService Manual fordetailsand part numbers. Ventheaterthrough wall/roof of
minimumthickness 0", maximum thickness 18".
ArrangementpourVentilation: Pour lesaérothermesà combustionséparée, la conduitede
fuméeet la prise d'airdoivent être situéesdansla même zone de pression. Onpeut utiliserle
système,concentriqueoptionel. Voirle manuel d'installation, de fonctionnement et d'entretien
pour lesdétailset lesréférencesde pièce. Ventilerl'aérotherme autraversd'un mur oud'un toit
avec une épaisseurminimum de 0" et une épaisseur maximum de 18".
Rating Plate Label
WARNING
This heater must be installed in accordance withthe manufacturer's
instructions and local codes. In the absence of local codes,follow
the National Fuel Gas Code,ANSI Z223.1 / NFPA 54 or the CAN/CSA-
B149 installation code.
Cet aérothermedoit être installé en accord avec les instructions du
fabricantet les régulations locaux. S'il n'y a pas des régulations locaux,
l'installation doit être en accordavec le Code National de Gaz de Carburant,
ANSI Z223.1 / NFPA54 ou le Code d'Installation, CAN/CSA-B149.
©2006 Roberts-Gordon, LLC P/N91010431 Rev Bwww.rg-inc.com
Printedin U.S.A. / Imprimé aux Etats Unis
Improper installation, adjustment,alteration, service or maintenance
can result in death, injury or property damage. Readthe Installation,
Operation and Service Manual thoroughly beforeinstalling or
servicing this equipment.
Installation,modification, réglage ou maintenance incorrectes
peuvent provoquerde la mort, des blessures ou des dégâts
matériels. Liser attentivementle manuel d'installation, d'operations
et d'entretien avant l'installation ou l'entretiende cet équipment.
Proposition 65
Label
Installation Label
Description Part Number
Logo Label 91040030
Cut Hazard Label 91010430
Vent Length Label 91039505
Vent to Outdoors Label 91010427
Warning Label 91010429
Rating Plate Label 91039802
Installation Label 91010431
Instruction Location Label 91010433
Lighting Instruction Label 91010425
Venting Arrangement Label* 91010426
Proposition 65 Label 91070015
* For separated combustion units only

UHD LOW PROFILE DUCT FURNACE INSTALLATION OPERATION AND SERVICE MANUAL
4 of 47
SECTION 2: INSTALLER RESPONSIBILITY
The installer is responsible for the following:
• To install the heater, as well as the gas and
electrical supplies, in accordance with applicable
specifications 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, vents and air
intakes.
• To provide access for servicing.
• To provide the owner with a copy of this
Installation, Operation and Service Manual.
• To never use heater as support for a ladder or
other access equipment and never hang or
suspend anything from heater.
• To ensure there is adequate air circulation
around the heater and to supply air for
combustion, ventilation and distribution in
accordance with local codes.
• To provide a method that ensures that the air flow
through the heat exchanger is within the
acceptable range indicated on the rating plate
prior to energizing the heater, and that such air
flowcontinues at least 90 seconds after the
heater is de-energized.
• To ensure the heater is placed in an approved
application.
2.1 Wall Tag
A laminated wall tag is included with the heater as a
permanent reminder of the safety instructions and
the importance of the required clearances to
combustibles. Affix the tag by peeling off the backing
of the adhesive strips on the rear surface and
position the tag on a wall near the heater.
A copy of the wall tag (P/N 91039831) is illustrated
on the back cover.
Knowyour model number. Model number is found
on the heater and throughout the Installation,
Operation and Service Manual.
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.
* HalogenatedHydrocarbons are a family of chemical
compoundscharacterized by the presence of halogen
elements(fluorine, chlorine, bromine, etc.). These com-
poundsare frequently used in refrigerants, cleaning
agents, solvents, etc. If these compoundsenter the air
supply of the burner, the life span of the heater compo-
nentswill be greatly reduced. An outside air supply must
be provided to the burnerswhenever the presence of
these compoundsissuspected. Warranty will be invalid
if the heater isexposed 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 3: CRITICAL CONSIDERATIONS
5 of 47
SECTION 3: CRITICAL CONSIDERATIONS
3.1 Basic Information
UHD[X][S] heaters have automatic ignition burners
for ON/OFF operation only.
3.2 Manufactured Units
Gas-fired, power-vented duct furnace with tubular
heat exchanger. Units shall have a minimum of 82%
thermal efficiency. The standard unit shall consist of
a non-separated combustion design with an
aluminized heat exchanger. Design and heat
exchanger alternatives shall be offered as follows:
• Separated Combustion: A separated
combustion unit shall feature an enclosed,
sealed burner box. A piece of flexible air duct
connects this burner box to a flange on the
cabinet. Combustion air should be ducted from
outside the heated space, with the ductwork
connecting to the unit with the use of the flange.
• Stainless Steel Heat Exchanger: A stainless
steel heat exchanger unit shall consist of heat
exchanger tubes, heat exchanger tube supports,
heat exchanger tube plates and vent box
produced of 409 stainless steel.
The use of stainless steel heat exchanger is
recommended when air inlet temperatures are
below40° F (4.4° C) or temperature rise is less
than 40° F (22.2° C) as condensation may form
on the heat exchanger resulting in corrosion that
may shorten its life.
3.3 Location and Suspension
All models:
•Must be installed indoors.
•Must be installed on the positive pressure side of
the air circulation blower.
•Must be installed in a level position with
horizontal discharge.
• May be mounted on a shelf of non-combustible
material using shelf mounting brackets.(See
Page 11, Figure 6 and Page 11, Figure 7 for
details.)
• Drop rods must be a minimum of 3/8" diameter
mild steel. Four suspension points (3/8" nuts)
are located on top of the heater.
• May be suspended from above (See Page 10,
Figure 5) or from wall brackets of sufficient
strength to support the heater as listed in the
Technical Data Table on Page 45, Section 16.2.
•Must be installed in a manner which allows
access to all serviceable components. See Page
6, Figure 3 for details.
3.4 Minimum Required Installation Clearances
Clearances around the heater and vent must be as
indicated on Page 6, Figure 3 and Page 14, Figure 8
to ensure access for servicing, and correct
operation.
3.5 Ventilation
It is important to ensure that there is adequate air
space around the heater to supply air for
combustion, ventilation and distribution in
accordance with local and national codes. See Page
12, Section 7.
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. See Page 20, Section 9.
3.7 Electrical Supply
A permanent 120 V/1 Ø/60 Hz electrical supply is
required for the main electrical power. The heater
also requires suitable controls in accordance with
Page 22, Section 10.
3.8Vent
Choose heater orientation to allowfor proper
location of the vent. Each heater must be fitted with
a correctly sized sealed vent system.
If vented horizontally, no other appliance may be
connected to the vent. See Page 12, Section 7.

UHD LOW PROFILE DUCT FURNACE INSTALLATION OPERATION AND SERVICE MANUAL
6 of 47
SECTION 4: CLEARANCES TO COMBUSTIBLES
4.1 Required Clearances to Combustibles
Clearances are the required distances that
combustible objects must be away from the heater
to prevent fire hazard. Combustible material that
may catch fire 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
serial plate of the heater and throughout the manual.
Check the clearances on the serial plate to make
sure the product is suitable for your application and
the clearances are maintained. Read and followthe
safety guidelines below:
• Keep gasoline or other combustible material
including flammable objects, liquids, dust or
vapors away from this heater or any other
appliance.
• The stated clearances to combustibles
represents a surface temperature of 90° F
(50° C) above room temperature. Building
materials with a lowheat tolerance (such as
plastics, vinyl siding, canvas, tri-ply, etc.) may be
subject to degradation at lower temperatures. It
is the installer's and owner's responsibility to
assure that adjacent materials are protected
from degradation.
•Consult local Fire Marshall, Fire Insurance
Carrier or other authorities for approval of
proposed installation when there is a possibility
of exposure to combustible airborne materials or
vapors.
4.2 Clearances to Combustibles
Clearances must be as indicated on Page 6, Figure
3. If clearances to combustibles are not indicated,
then installation clearances apply.
Figure 3: Clearances to Combustibles
WARNING
Fire Hazard
Keep all flammable objects, liquids and
vapors 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.
Clearance to Vent: 2" (5 cm)
*18" (46 cm) minimum is necessary for
servicing.

SECTION 5: NATIONAL STANDARDS AND APPLICABLE CODES
7 of 47
SECTION 5: NATIONAL STANDARDS AND APPLICABLE CODES
5.1 Gas Codes
The type of gas appearing on the name plate
must be the type of gas used. Installation must
comply with national and local codes and
requirements of the local gas company.
United States: Refer to NFPA 54/ ANSI Z223.1 -
latest revision, National Fuel Gas Code.
Canada: Refer to CSA B149.1 Natural Gas and
Propane Installation Code.
5.2 Aircraft Hangars
Installation in aircraft hangars must be in
accordance with the following codes:
United States: Refer to Standard for Aircraft
Hangars, NFPA 409 - latest revision.
Canada: Refer to Standard CSA B149.1 Natural
Gas and Propane Installation Code.
• In aircraft storage and servicing areas, heaters
shall be installed at least 10' (3 m) above the
upper surface of wings or of engine enclosures
of the highest aircraft which may be housed in
the hangar. The measurement shall be made
from the wing or engine enclosure (whichever is
higher from the floor) to the bottom of the
heater.
• In shops, offices and other sections of aircraft
hangars communicating with aircraft storage or
servicing areas, heaters shall be installed not
less than 8' (2.4 m) above the floor.
• Suspended or elevated heaters shall be so
located in all spaces of aircraft hangars that
they shall not be subject to injury by aircraft,
cranes, movable scaffolding or other objects.
Provisions shall be made to assure accessibility
to suspended heaters for recurrent
maintenance purposes.
5.3 ParkingStructures and Repair Garages
Installation in garages must be in accordance
with the following codes:
United States: Standard for Parking Structures
NFPA 88A - latest revision or the Code for Motor
Fuel Dispensing Facilities and Repair Garages,
NFPA 30A - latest revision. Canada: Refer to
CSA B149.1 Natural Gas and Propane
Installation Code.
• In accordance with the Standard for Parking
Structures NFPA 88A, heaters must be located
a minimum of 18" (50 cm) belowthe floor-ceiling
assembly or 18" (50 cm) above the floor.
• In accordance with the Code for Motor Fuel
Dispensing Facilities and Repair Garages,
NFPA 30A - latest revision, heaters must not be
installed less than 8' (2.4 m) above the floor.
5.4 Electrical
The heater must be electrically grounded in
accordance with the following codes:
United States: Refer to National Electrical
Code®, NFPA 70 - latest revision. Wiring must
conform to the most current National Electrical
Code®, local ordinances and any special
diagrams furnished.
Canada: Refer to Canadian Electrical Code,
CSA C22.1 Part 1 - latest revision.
5.5 Venting
The venting must be installed in accordance
with the requirements within this manual and
the following codes:
United States: Refer to NFPA 54/ANSI Z223.1 -
latest revision, National Fuel Gas Code.
Canada: Refer to CSA B149.1 Natural Gas and
Propane Installation Code.

UHD LOW PROFILE DUCT FURNACE INSTALLATION OPERATION AND SERVICE MANUAL
8 of 47
5.6 High Altitude
These heaters are approved (without
modifications) for installations up to 2000' (610
m) in US and Canada. Heaters installed above
2000' (610 m) must be de-rated. For
installations above 2000' (610 m) in US, consult
factory for information on burner de-rating. For
installations from 2000' (610 m) to 4500'
(1370m) in Canada, high altitude conversion
kits are available. Heaters installed over 4500'
(1370 m) in Canada are not approved and must
be approved by the local or provincial authority.

SECTION 6: DUCT HEATER INSTALLATION
9 of 47
SECTION 6: DUCT HEATER INSTALLATION
6.1 General
To connect the inlet and outlet ducts to the heater,
Duct-Mate or similar flanges may be slid over the
duct connector flanges supplied on the unit and
secured with screws. The connection to the duct
then can be made using the Duct-Mate clips. The
ducts must have removable access panels
upstream and downstream of the heater. These
panels must be of appropriate size and placement
so that smoke or reflected light could be observed to
indicate the presence of leaks in the heat
exchanger. Covers for these openings should be
sealed to prevent leakage.
Any transition into the inlet of the heater should be
smooth, with a taper of no more than 15 degrees. If
elbows are required, they should be of either broad
radius or fitted with properly designed air turns.
Consult a professional to ensure air turns are
properly designed.
The heater must be installed on the positive
pressure side of the circulating air blower. Air flow
through the heater must be as shown on Page 9,
Figure 4 and may not be reversed. The air flowmust
be adjusted such that it is within the acceptable
range shown on Page 9, Section 6.1.3. The
minimum inlet duct lengths shown on Page 9,
Section 6.1.1 should be observed. Pressure drop
through the heat exchanger at various air flows is
given on Page 9, Section 6.1.2.
Figure 4: Air Flow Direction
6.1.1 Minimum Inlet Duct Length
6.1.2 Temperature Rise and Pressure Drop Ranges
6.1.3 Air Flow and Temperature Rise Ranges
AIR FLOW
OUTLET DUCT
INLET DUCT
Model Duct Length Duct Size (W X H)
UHD[X][S] 75 32" (81 cm) 16 3/4" x 15 7/8" (43 cm x 40 cm)
UHD[X][S] 100 &125 37" (94 cm) 21 3/4" x 15 7/8" (55 cm x 40 cm)
UHD[X][S] 75 UHD[X][S] 100 UHD[X][S] 125
Airflow
(CFM)
Temperature
Rise (°F)
Pressure Drop
(in wc)
Airflow
(CFM)
Temperature
Rise (°F)
PressureDrop
(in wc)
Airflow
(CFM)
Temperature
Rise (°F)
Pressure Drop
(in wc)
850 68 0.06 950 78 0.05 1,020 92 0.06
1,200 48 0.10 1,500 50 0.18 1,650 57 0.14
1,625 36 0.16 2,500 31 0.28 2,340 41 0.27
1,965 30 0.22 3,000 26 0.39 3,480 28 0.56
2,450 24 0.31 3,300 24 0.46 4,240 23 0.80
2,650 22 0.36 3,660 22 0.55 4,750 20 0.98
Model Rate Air Flow Temperature Rise
(Btu/h) Minimum (CFM) Maximum (CFM) Minimum (°F) Maximum (°F)
UHD[X][S] 75 75,000 850 2,650 22 68
UHD[X][S] 100 100,000 950 3,660 22 78
UHD[X][S] 125 125,000 1,020 4,750 20 92

UHD LOW PROFILE DUCT FURNACE INSTALLATION OPERATION AND SERVICE MANUAL
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6.2 Shelf Mountingand Suspension
Four suspension points (3/8" nuts) are located on
the top of the heater. Drop rods must be 3/8"
diameter mild steel minimum.
When handling or supporting the heater from below,
ensure that the weight is taken at the support points.
For typical suspension, See Page 10, Figure 5.
For typical shelf mounting on existing shelf, See
Page 11, Figure 6.
The gas or electrical supply lines must not be used
to support the heater.
Do not locate the gas or electrical supply lines
directly over the path of the flue products from the
heater.
The heater must be installed in a location that is
readily accessible for servicing.
The heater must be installed in accordance with
clearances to combustibles as indicated on the wall
tag and in this manual.
6.3 Wall Mounting
For typical suspension, See Page 11, Figure 7. Wall
mounted 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 using all mounting holes. Screwsizes
less than 3/8" may not be used. In order for the wall
mounting brackets to adequately carry the weight of
the heater, it must be installed according to best
building practices.
Figure 5: Suspension Methods
WARNING
Crush Hazard
Use 3/8" threaded rod
minimum.
Failure to follow these
instructions can result in
death, injury or property
damage.

SECTION 6: DUCT HEATER INSTALLATION
11 of 47
Figure 6: Shelf-MountingMethods
Figure 7: Wall Shelf Mountingand Suspension
Shelf Mounting
Brackets
Description Part Number Qty.
Shelf MountingBracket Kit 12011000K
Shelf Mounting Bracket 11111510 2
Screw#10 x 1/2"
Type AB Phil HWH Z 94311008 2
Existing cabinet screws must be re-used.
Shelf
Mounting
Brackets
(Fasten to
Wall Mounting
Bracket)
5/16" x 3 1/2" Bolt
5/16" Flat Washer
5/16" Locknut with Nylon Insert
Torque to 40 in lb(4.5 Nm).
Wall Shelf Mounting
Wall Mounting
Bracket Arm
(Right & Left)
Wall Suspension Mounting
Wall Mounting
Bracket Vertical
Wall Mounting
Bracket Diagonal
3/8" Fasteners
Description Part Number Qty.
Wall Shelf MountingBracket Kit 12011002K
Wall Suspension Mounting Bracket Kit 12011001K 1
Shelf Mounting Bracket Kit 12011000K 1
Description Part Number Qty.
Wall Suspension MountingBracket Kit 12011001K
Wall Mounting Bracket Arm Left 111WALL1L 1
Wall Mounting Bracket Arm Right 111WALL1R 1
Wall Mounting Bracket Vertical 111WALL2 2
Wall Mounting Bracket Diagonal 111WALL3 2
5/16" x 3 1/2" Bolt 97213925 6
5/16" Lock Nut with Nylon Insert 92114000 6
5/16" Flat Washer 95211600 6
5/16" Lockwasher 96411600 6
Hardware provided to construct mounting bracket assembly only.

UHD LOW PROFILE DUCT FURNACE INSTALLATION OPERATION AND SERVICE MANUAL
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SECTION 7: VENTING
7.1 ChangingVent and Air Intake Orientation
The heater is sold with rear horizontal vent and air
intake connections as standard. (Only separated
combustion models have air intake connection). If
vertical vent and air intake connections are required,
followthe instructions on Page 42, Section 15.5.
7. 2 Ve n t i n g
This heater must be vented in accordance with the
rules contained in this manual and with the following
national codes and any state, provincial or local
codes which may apply: United States: Refer to
NFPA54/ANSI Z223.1 - latest revision, National Fuel
Gas Code; Canada: Refer to CSA B149.1 Natural
Gas and Propane Installation Code.
Any portion of vent pipe passing through a
combustible wall must have a listed thimble to
conform with the above codes.
The heater may be installed unvented in
certain circumstances according to building
ventilation codes. Refer to the above codes and
Page 13, Section 7.4 for further information.
Unvented operation also requires compliance with
the clearances to combustibles given on Page 6,
Figure 3.
The bottom of the vent or air intake terminal shall not
be located less than 1' (.3 m) above grade level.
The vent shall not terminate less than 7' (2.1 m)
above grade where located adjacent to public
walkways.
Vent terminal must be installed at a height sufficient
to prevent blockage by snowand building materials
protected from degradation by flue gasses.
Vent terminal must be beyond any combustible
overhang.
Secure all joints with corrosion resistant #8 x 3/8"
sheet metal screws.
For single wall venting, pressure sensitive aluminum
tape or silicone sealant must be used to seal all
joints.
Aluminum tape shall have a minimum temperature
rating of 400° F (204° C) and meet SMACNA AFTS-
100-73 standards. High temperature silicone sealant
must have a minimum temperature rating of 480° F
(250° C).
7.2.1 United States Requirements
Vent must terminate at least 3' (.9 m) above any
forced air inlet located within 10' (3.1 m).
Vent must terminate at least 4' (1.2 m) below,
4' (1.2 m) horizontally from, or 1' (.3 m) above any
door, operable window, or gravity air inlet into any
building.
NFPA 54/ANSI Z223.1 - latest revision, National
Fuel Gas Code specifies a 4' (1.2 m) horizontal vent
terminal clearance from gas and electric meters,
regulators and relief equipment.
7.2.2 Canadian Requirements
The vent shall not terminate within 6' (1.8 m) of a
mechanical air supply inlet to any building.
The vent shall not terminate within 3' (.9 m) of a
windowor door that can be opened in any building,
any non-mechanical air supply inlet to any building,
or of the combustion air inlet of any other appliance.
7.3 Vent Installation
Maintain clearances to combustibles at all times for
safety. Clearances are the required distances that
combustible objects must be away from the heater
to prevent serious fire hazard. See Page 6, Section
4. For vented units, the vent must terminate outside
of the building.
Vents must be fully sealed and correctly sized for
the model. If the vent passes through a wall or
ceiling of combustible material, it must be enclosed
by a listed thimble and be separated from the
thimble by at least a 2" (5 cm) air gap.
For separated combustion models, vents and air
intakes must be a fully sealed system and correctly
sized for the model. Vent should be assembled as
detailed on Page 14, Figure 8 through Page 18,
Figure 13. The joints between the vent terminal and
the roof or wall must be properly sealed. If the vent
passes through a wall or ceiling of combustible
material, it must be enclosed by a listed thimble and
be separated from the thimble by at least a 2" (5 cm)
air gap.
WARNING
Carbon Monoxide Hazard
Heaters may be installed
vented or unvented.
Vented heaters must be
vented outdoors.
Unvented heaters must be
installed according to the
installation manual.
Failure to follow these
instructions can result in
death or injury.