Roberts Gorden 400, 225, 200, 300, 150 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

Fire Hazard

Do not store or use gasoline or other flammable vapors 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 contractor qualified in the installation and service of gas-fired heating equipment or your gas supplier.

Quality in Any Language™

© 2008 Roberts-Gordon LLC

Combat®

UHA-Series

Tubular Unit Heaters

(Standard Range)

Installation, Operation

& Service Manual

Models UHA[S] 150, 175, 200, 225 250, 300, 350, 400

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.rg-inc.com

P/N 111101NA 06/08 Rev. E

TABLE OF CONTENTS

SECTION 1: Heater Safety......................................................		1	SECTION 11: User Instructions............................................		22
1.1 Manpower Requirements .............................................		1	11.1 User Instructions.......................................................		22
SECTION 2: Installer Responsibility .....................................		2	11.2 Heater Operation ......................................................		22
2.1	Wall Tag .......................................................................	2	11.3 Lighting Instructions..................................................		22
2.2	Corrosive Chemicals....................................................	2	11.4 Simple Troubleshooting.............................................		22
2.3	National Standards and Applicable Codes ..................	2	SECTION 12: Servicing.........................................................		24
SECTION 3: Critical Considerations .....................................		3	12.1	Servicing Instructions...............................................	24
3.1	Basic Information .........................................................	3	12.2	Burner Maintenance.................................................	24
3.2	Location and Suspension ............................................	3	12.3	Fan/Motor Assembly Maintenance...........................	24
3.3	Minimum Required Installation Clearances .................	3	12.4	Heat Exchanger Maintenance ..................................	24
3.4	Clearances to Combustibles ........................................	3	12.5	Gas Valve Maintenance ...........................................	24
3.5	Ventilation ....................................................................	3	12.6	Flue Blower ..............................................................	24
3.6	Gas Supply ..................................................................	3	12.7	Venting and Air Intake Pipe ......................................	24
3.7	Electrical Supply ..........................................................	3	12.8	Maintenance Checklist .............................................	25
3.8	Vent..............................................................................	3	SECTION 13: Troubleshooting .............................................		27
3.9	Separated Combustion Installation ..............................	3	13.1	General ....................................................................	27
SECTION 4: National Standards and Applicable Codes .....		5	13.2	Troubleshooting For Automatic Ignition
4.1	Gas Codes...................................................................	5		Burner Systems .......................................................	28
4.2	Aircraft Hangars ...........................................................	5	13.3	Troubleshooting for Flame Supervision System .......	29
4.3	Parking Structures and Repair Garages......................	5	13.4	Troubleshooting for Gas Valves................................	30
4.4	Electrical ......................................................................	5	13.5	Troubleshooting for Flue Blower ...............................	30
4.5	Venting.........................................................................	5	SECTION 14: Replacement Parts.........................................		31
4.6	High Altitude ................................................................	5	14.1	Gas Valve .................................................................	31
SECTION 5: Major Components ............................................		6	14.2	Burner Compartment ...............................................	32
5.1	General........................................................................	6	14.3	Ignition Electrode and Flame Probe .........................	33
5.2	Suspension..................................................................	6	14.4	Heat Exchanger .......................................................	34
SECTION 6: Venting................................................................		7	14.5	Louvers and Louver Spring ......................................	34
6.1	Venting.........................................................................	7	14.6	Flue Blower .............................................................	35
6.2	Vent Installation ...........................................................	7	14.7	Pressure Switch........................................................	36
6.3	Unvented Operation.....................................................	8	14.8	Ignition Control .........................................................	36
6.4	Horizontal Venting........................................................	8	14.9	Axial Fan/Guard/Motor Assembly.............................	36
6.5	Vertical Venting............................................................	8	14.10 Limit Switches ........................................................		37
6.6	Length Requirements ..................................................	8	SECTION 15: Specifications.................................................		38
6.7	Vent Material................................................................	9	15.1	Standard (Models 150 - 400) UHA[S] Series
SECTION 7: Air Supply.........................................................		13		Dimension Data .......................................................	38
7.1 Separated Combustion Installation.............................		13	15.2	General Technical Data Table (All Models) ..............	39
7.2 Unvented Installation ..................................................		13	15.3	Technical Data Table (All Models) ............................	39
7.3 Building Ventilation .....................................................		13	SECTION 16: The ROBERTS GORDON® COMBAT®
7.4 Outside Combustion Air Supply..................................		13		UHA-Series Warranty .....................................	41
SECTION 8: Gas Piping ........................................................		14
8.1	Connections...............................................................	14
SECTION 9: Wiring................................................................		15
9.1	Positioning Thermostats ............................................	15
9.2	Low Voltage Thermostat with One Heater .................	15
9.3	UHA[S] Series Internal Wiring Diagram.....................	16
9.4	UHA[S] Series Ladder Wiring Diagram......................	17
9.5	Electrical Connection to the Heater ...........................	18
SECTION 10: Operation and Maintenance..........................		19
10.1 Pre-Start-Up Checks................................................		19
10.2 Begin Start-Up .........................................................		19
10.3 Complete the Start-Up .............................................		21

© 2008 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 .................................................	6
Figure 3: Vent and Roof Detail ..................................................	9
Figure 4: Standard Vented Heater - Vertical
and Horizontal Vent Termination................................	9
Figure 5: Standard Vented Heater - Common
Vertical Vent Termination .........................................	10
Figure 6: Separated Combustion Heater - Vertical
and Horizontal Vent Termination..............................	11
Figure 7: Concentric Vent Box ................................................	11
Figure 8: Concentric Vertical and Horizontal Vent
Termination - Separated Combustion Heater ..........	12
Figure 9: Gas Connection .......................................................	14
Figure 10: Automatic Burner Control Sequence......................	20
Figure 11: Gas Valve for Models UHA[S] 150 - 400 ................	20
Figure 12: LED Diagnostic Codes...........................................	22

SECTION 1: HEATER SAFETY

SECTION 1: HEATER SAFETY

Your Safety is Important to Us! This symbol is used throughout the manual to notify you of possible fire, electrical or burn hazards. Please pay special

attention when reading and following the warnings in these sections.

Installation, Service and Annual Inspection of heater must be done by a 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 installation. 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.

Thin sheet metal parts, including the various venting components, have sharp edges. To prevent injury, the use of work gloves is recommended.

Before installation, ch‘eck that the local distribution conditions, nature of gas and pressure and adjustment of the appliance are compatible.

1.1 Manpower Requirements

To prevent personal injury and damage to the heater, two persons will be required for installation.

1

COMBAT® UHA UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

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 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.

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 91040031) is illustrated on the back cover.

Know your model number. Model number is found on the heater and in the Installation, Operation and Service Manual. See Page 9, Figure 3 through Page 14, Figure 9.

2.2 Corrosive Chemicals

CAUTION

Do not use heater in an area containing corrosive chemicals.

Avoid the use of corrosive chemicals to ensure a longer life of the burner, heat exchanger and other parts.

Failure to follow these instructions can result in property damage.

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 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 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 compounds 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.

2

SECTION 3: CRITICAL CONSIDERATIONS

SECTION 3: CRITICAL CONSIDERATIONS 3.1 Basic Information

UHA[S] 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 discharge.

•May be mounted on a shelf of non-combustible material.

•May be suspended from above (See Page 6, Figure 2) or from wall brackets of sufficient strength to support the heater as listed in the Dimension Data Table on Page 38, Section 15.1. 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.

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

See Page 4, Figure 1 for details.

3.3 Minimum Required Installation Clearances

Clearances around the heater and vent must be as indicated on Page 4, Figure 1; Page 9, Figure 3 through Page 12, Figure 8 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 space around the heater to supply air for combustion, ventilation and distribution in accordance with local and national codes on Page 7, Section 6.

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 on Page 14, Section 8.

3.7 Electrical Supply

A permanent 120 V 60 Hz 1 Ø electrical supply is required for the main electrical power. The heater also requires suitable controls in accordance with

See Page 15, Section 9.

3.8 Vent

Choose heater orientation to allow for the 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 7, Section 6.

3.9 Separated Combustion Installation

For separated combustion installation, the vent and air intake must be fitted with an individual and correctly sized sealed system and the vent and air intake must terminate at approved wall and roof terminals.

Separated combustion units may not be common vented. See Page 7, Section 6.

3

COMBAT® UHA 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 vapors the required clearances to combustibles away from heater.

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

Figure 1: Installation Clearances and Clearances to Combustibles

Installation Clearances

(Optional separated combustion concentric venting shown.)

			Top
	Wall	24" for	10'
			(3 m)
		adequate
	Terminal	air flow access
		axial fan.

20' (6.0 m) - 30' (9.1 m) Max. Mounting Height*

* Recommended mounting height varies with heater input. Heaters may be mounted at a higher level if destratification fans are installed.

Note: Venting directly from top of heater not applicable on Models 150 - 400.

Clearances to Combustibles

	6"
	(15 cm)
6"**	31"
(15 cm)	(79 cm)
	3"

Clearance to Vent: 2" (5 cm)

**31" (79 cm) minimum is necessary for servicing.

The heater must always be installed at least 6' (2 m) above the floor. The vent pipe must have clearance from combustibles by 2" (5 cm).

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

4

SECTION 4: NATIONAL STANDARDS AND APPLICABLE CODES

SECTION 4: NATIONAL STANDARDS AND APPLICABLE CODES

4.1 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.

4.2 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.

4.3 Parking Structures 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) below the 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.

4.4 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.

4.5 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.

4.6 High Altitude

These heaters are approved for installations up to 2000' (610 m). In USA, consult factory if heater is to be installed above 2000' (610 m). In Canada, high altitude conversion kits are available for installations up to 4500' (1370 m). Installations above 4500' (1370 m) in Canada is by local or provincial authority.

5

COMBAT® UHA UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

SECTION 5: MAJOR COMPONENTS 5.1 General

Heaters are designed for installation above 6'

(1.8 m). These heaters must be installed within the heated space. Duct delivery systems are not permitted with axial fan units. When handling or supporting the heater from below, ensure that the weight is taken at the support points.

5.2 Suspension

WARNING

Crush Hazard

Use 3/8" threaded rod minimum.

Failure of the supports can result in death, injury

or property damage.

For typical suspension, See Page 6, Figure 2.

Figure 2: Suspension Methods

Unistrut	Channel Nut
Washer
Nut
3/8"
Threaded
Rod
	Point
	Pin
	Window
	Clamp
3/8"
Threaded
Rod	Unistrut
Nut
Washer
Riv
Nut
	Support Points
6

SECTION 6: VENTING

SECTION 6: VENTING 6.1 Venting

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 NFPA 54/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 8, Section 6.3 for further information.

Unvented operation also requires compliance with the clearances to combustibles given on Page 4, Figure 1.

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 snow and 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).

6.1.1 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.

6.1.2 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 window or 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.

6.2 Vent Installation

WARNING

Fire Hazard

Some objects will 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.

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 9, Figure 3 through Page 12, Figure 8. 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.

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

For vent termination See Page 9, Figure 3 through Page 12, Figure 8.

6.2.1Standard Vented Heaters (Models UHA 150 - 400)

The vent must be fitted with a low resistance terminal. See Page 9, Figure 3 through Page 9, Figure 4. Standard vented heaters do not allow outdoor air intake for combustion air.

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COMBAT® UHA UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

6.2.2Separated Combustion Heaters (Models UHAS 150 - 400)

The heaters are designed to be installed as separated combustion heaters. The vent and air intake are run as separate pipes to the wall or roof terminals. See Page 12, Figure 8. As an option, the vent and air intake are run as separate pipes to a concentric vent box and a concentric vent/air intake pipe penetrates the wall or roof.

6.3 Unvented Operation

WARNING

Carbon Monoxide Hazard

Heaters installed unvented must be interlocked with sufficient building exhaust.

Heaters must be installed according to the installation manual.

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

For unvented operation in commercial installations, sufficient ventilation must be provided in the amount of 4 cfm per 1000 Btu/h firing rate (United States); 3 cfm per 1000 Btu/h firing rate (Canada).

WARNING: Combustion by-products contain a chemical known to the State of California to cause cancer and birth defects or other reproductive harm.

6.4 Horizontal Venting

Horizontally vented heaters must be individually vented.

Vent pipe must be sloped ¼" (.6 cm) for every 1' (.3 m). For vent lengths greater than 5' (1.5 m), condensation will form. Insulation is recommended and condensation drains may be desired. For vents pitched up toward the vent terminal, place the condensation drain within 5' (1.5 m) of the heater.

In noncombustible walls only, vent terminal (P/N 02537801-1P) may be used.

For 4'' (10 cm) vents in either combustible or noncombustible walls, use vent terminal (P/N 90502100) or equivalent insulated vent terminal. Follow the manufacturer's instructions for proper installation.

Instead of an insulated vent terminal, a listed thimble (with 2" air gap) may be used with a 4" vent cap (P/N 90502102).

6.5 Vertical Venting

Vertically vented heaters can be common vented (up to 4 heaters).

For vent lengths greater than 5' (1.5 m), condensation will form. Insulation is recommended and condensation drains may be desired. Vent from the rear of the heater cabinet then run the vent vertically and use a condensate drain at the bottom of the vertical vent.

Vent pipe must be sloped 1/4'' (.6 cm) for every 1' (.3 m).

For 4'' (10 cm), an approved vent cap (P/N 90502102) must be used.

For 6'' (15 cm) common vent, an approved vent cap (P/N 90502103) must be used.

For common vertical venting of more than two heaters, See Page 10, Figure 5.

A vent shall not extend less than 2' (.6m) above the highest point where it passes through a flat roof of a building.

6.6 Length Requirements

If using vent lengths greater than 5' (1.5 m), condensation will form in the vent pipe. Insulation and additional sealing measures (high temperature silicone at all seams) are required.

The entire vent should be insulated with foil faced fiberglass insulation (1/2" thick, 1-1/2# density minimum).

Maximum Vent Lengths Table

	Model UHA[S]	# of Elbows
	150 - 400
	40 ft (12.2 m)	1
	35 ft (10.7 m)	2
	30 ft (9.1 m)	3
	25 ft (7.6 m)	4
	20 ft (6.1 m)	5

8

SECTION 6: VENTING

6.7 Vent Material

Vent material may be single wall 26 ga. (minimum) galvanized steel or equal thickness stainless steel. Completely seal all joints, refer to Page 7, Section 6.2.

If penetrating a combustible wall or roof, a listed thimble with 2" (5 cm) clearance must be used. Where local codes permit, a single section of type B-1 vent material may be used at the roof or wall penetration instead of a thimble. Ensure vent manufacturer's clearance from vent material is maintained. Seal annular space of the type B-1 vent as well as all joints in the remaining vent.

Figure 3: Vent and Roof Detail

Vent
Terminal
	Flashing
	or Rain Collar
Roof
	Listed Thimble
2" Air Gap to	Vent
Combustible Material

Figure 4: Standard Vented Heater - Vertical and Horizontal Vent Termination

Vent Terminal

Flashing

(By Others)

Listed

Thimble

(2" Clearance)

		Listed
Vertical	90°	Thimble
		(2" Clearance)
Option	Bend	Flashing
	Horizontal
		(By Others)
	Option
	Vent		Vent
			Terminal
	Condensate	12" (31 cm)	Note: Vent supports
		Minimum
	Trap to Drain		not shown.
	(Optional)

Model	Vent Diameter	Part Number
UHA 150 - 400	4" (10 cm)	90502102

9

COMBAT® UHA UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

Figure 5: Standard Vented Heater - Common Vertical Vent Termination

											Type "B" vent cap
											(7" or 8") may be used.
											(These are not available
SIDE VIEW											from Roberts-Gordon.)
											Type "B" Vent Pipe

18" (46 cm)	Roof
Min.	Flashing
	Roof

The last section of vent pipe		Approved
passing through the roof or
wall may be Type "B" vent pipe.		Thimble
All other vent materials in the		(If Applicable)
building must be single wall		Single Wall Pipe
vent pipe.
4" (10 cm)	"D"	"D" Area must equal sum	4" (10 cm)
Single Wall Pipe			Single Wall Pipe
		of open area of

individual vents.

TOP VIEW

10