Laars Mini-Therm JVi JVH, Mini-Therm JVi JVP Installation And Operation Instructions Manual

Installation and Operation Instructions Document 1080C

Installation and
Operation
Instructions for

Mini-Therm JVi

Induced Draft
Residential
Gas-Fired
Hydronic Boilers

Models JVH, JVP

These instructions are to be stored next to the boiler for reference purposes.

FOR YOUR SAFETY: This product must be installed and serviced by a professional service technician,

qualified in hydronic boiler installation and maintenance. Improper installation and/or operation could
create carbon monoxide gas in flue gases which could cause serious injury, property damage, or death.
Improper installation and/or operation will void the warranty.

WARNING

If the information in this manual is not followed exactly, a fire or explosion may result
causing property damage, personal injury or loss of life.

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

WHAT TO DO IF YOU SMELL GAS

• Do not try to light any appliance.

• Do not touch any electrical switch; do not use any phone in your building.

• Immediately call your gas supplier from a nearby phone. Follow the gas supplier's
instructions.

• If you cannot reach your gas supplier, call the fire department.

Installation and service must be performed by a qualified installer, service agency, or gas
supplier.

H2020900C

Page 2

LAARS HEATING SYSTEMS

TABLE OF CONTENTS

SECTION 1.
General Information

1A. Introduction...................................................3

1B. Warranty....................................................... 3

1C. Heater Identification .....................................3

1D. Flow Requirements ......................................3

1E. Boiler Placement ..........................................4

1F. Gas Supply and Piping .................................4

1G. Combustion Air Supply.................................5

1H. Venting ......................................................... 6

1H-1. Vertical Venting - Category I.........................7

1H-2. Horizontal Venting - Category III .................. 8

1H-3. Common Venting System............................. 9

1I. Water Piping of Boiler System.................... 10

1I-1. By-Pass Piping ........................................... 10

1J. Chilled Water Systems ...............................10

1K. Electrical Wiring.......................................... 12

1L. Filling the System ....................................... 12

SECTION 2.
Operating Procedures

2A. System Start-up.......................................... 15

2B. Sequence of Operation .............................. 17

SECTION 3.

3A. Maintenance............................................... 17

3B. Electrical Troubleshooting .......................... 18

Mini-Therm JVi

Page 3

SECTION 1.
General Information

WARNING

The JVi induced draft hydronic boiler must be
installed in accordance with the procedures detailed
in this manual, or the Laars warranty will be voided.
The installation must conform to the requirements
of the local jurisdiction having authority, and, in the
United States, to the latest edition of the National
Fuel Gas Code, ANSI Z223.1. In Canada, the
installation must conform with the latest edition of
CAN/CGA B149.1 OR .2 installation codes for gas
burning appliances, and/or local codes.
Any modifications to the boiler, its gas controls, gas
orifices, wiring or draft inducer assembly may void
the warranty. If field conditions require
modifications, consult the factory representative
before initiating such modifications.

1A. Introduction

This manual provides information necessary for
the installation, operation, and maintenance of the
Laars Model JVi induced draft, low pressure, copper
tube hydronic boilers. These boilers are available in
two configurations; the JVH has a hot surface pilot
ignition system and the JVP has an electronic
intermittent ignition device (I.I.D.). Look for the
model designation on the rating plate, which can be
found on top of the boiler.

All application and installation procedures
should be reviewed completely before proceeding with
the installation. Consult the Laars factory, or local
factory representative, with any problems or questions
regarding this equipment. Experience has shown that
most operating problems are caused by improper
installation.

1B. Warranty

The Laars Model JVi induced draft boilers are
covered by a limited warranty. A copy of the warranty

is printed on the back cover of this manual. The owner
should fill out the warranty registration card and
return it to Laars.

All warranty claims must be made to an
authorized Laars representative or directly to the
factory. Claims must include the boiler serial number
and model (this information can be found on the rating
plate), installation date and name of the installer.
Shipping costs are not included in the warranty
coverage. Some accessory items are shipped in
separate packages. Verify receipt of all packages listed
on the packing slip. Inspect each item for damage
immediately upon delivery, and advise the carrier of
any shortages or damage. Any such claims should be
filed with the carrier. The carrier, not the shipper, is
responsible for shortages and damage to the shipment
whether visible or concealed .

1C. Heater Identification

Consult the rating plate on the boiler. The
following example simplifies the heater identification:

123456

JV H 125 N C S

Table 1. Heater Identification.

1. Basic boiler series model

2. Ignition system: (H) Hot surface pilot ignition

(P) Spark ignition

3. Input rate X 1000 BTU/Hr

4. Gas Type: (N) Natural (P) Propane

5. Firing rate: (C) On/off, induced draft

6. Options: (S) Standard, (P) with Pump,

(A) Extra Aquastat

1D. Flow Requirements

All high recovery, low volume water boilers
must have adequate flow for proper operation. Pump
selection is critical to this goal, and pumps should be
selected to provide for correct system design water
temperature rise. Table 2 details temperature rise and
water flow for the Mini-Therm boilers.

8°C

15°F

Size

50 5.3

75 8.0
100 10.7
125 13.3
160 17.0
225 24.0

ft = Pressure drop (headloss) through the boiler in feet of water.m = Pressure drop (headloss) through the boiler in meters of water.

Flow Rate Headloss Flow Rate Headloss Flow Rate Headloss

gpm

l/s

0.3

0.5

0.7

0.8

1.1

1.5

ft

0.3

0.6

1.3

2.2

2.5

5.0

gpm = Water Flow in gallons per minute.

Note: Shaded area is the recommended flow and temperature rise.

11°C

20°F

m

0.1

0.2

0.4

0.7

0.8

1.5

Table 2. Temperature Rise (degrees °F,

gpm

4.0

6.0

8.0

10.0

12.8

18.0

l/s

0.3

0.4

0.5

0.6

0.8

1.1

ft

0.2

0.3

0.7

1.3

1.8

3.1

l/s

= Water flow in liters per second.

m

0.1

0.1

0.2

0.4

0.5

0.9

degrees °C

).

gpm

3.2

4.8

6.4

8.0

10.2

14.4

l/s

0.2

0.3

0.4

0.5

0.6

0.9

25°F

14°C

0.1

0.2

0.5

0.8

1.2

1.9

ft

m

0.0

0.1

0.2

0.2

0.4

0.6

Page 4

LAARS HEATING SYSTEMS

Damage from improper flow is not warranted.

Failure to insure proper water flow through the
heat exchanger of the boiler will void the Laars
warranty. Flow can be verified by measuring the
difference in water temperatures between the boiler
inlet (system return) and outlet (system supply). For
example: For a JV-100 installation, the inlet water
temperature is 160°F (71ºC), and the outlet temp­erature is 180°F (82ºC). That means there is a 20ºF
(11ºC) temperature rise through the boiler. According
to Table 2, that would indicate a flow rate of 8 gpm
(0.5 l/s). Temperature rise must be measured with the
longest (highest head) zone calling for heat alone.

Other factors to be considered before selecting a
pump are pipe size, the number and type of fittings
throughout the system, smoothness of the interior
surface of the pipe, the quantity of water flowing
through the pipe, whether a glycol solution (for freeze
protection) is being used, and the total length of piping
in the system. Table 3 can help in proper pump
selection.

1/2" Pipe 3/4" Pipe 1" Pipe 1-1/4" Pipe

Size

Pump

H.P.

1/25 1/12 1/25 1/12 1/6 1/25 1/12 1/6 1/25 1/12 1/6
50 50 99 390 680 * * * * * * *
75 * 35 160 300 460 640 * * * * *

100 * * 77 150 260 330 620 * * * *
125 * * 27 80 140 170 360 600 * * *
160 * * * 25 72 57 160 330 190 480 *
225 * * * * * * * 110 * 69 330

*A circular and/or primary/secondary piping are required. Consult factory.

1. Chart is based on 30°F (17°C) maximum temperature rise.

2. Calculations are based on Type L copper tubing with one zone valve
and eight elbows.

3. Typical circulating pumps: 1/25 HP=Taco 007, B&G LR-20 or SLC-25,
Grundfos UP15-42F, or equivalent. 1/2 HP=B&G LR-12, Grudnfos
U26-42F, or equivalent. 1/6 HP=B&G series HV, Grundfo UP43-75,
or equivalent.

Table 3. Maximum Suggested Circuit Length in Feet.

Pump H.P. Pump H.P. Pump H.P.

1E. Boiler Placement

WARNING

This boiler is intended for indoor installation only.

1. The boiler must be placed to provide clearances
on all sides for maintenance and inspection.
There must also be minimum distances
maintained from combustible surfaces. Avoid
locations which can be damaged by water or
moisture.

2. A minimum of 15" (381mm) access must be
available in front of the boiler for burner tray
removal. Consult local codes for clearances to
hot water pipes and accessories.

4

(102)

6

(152)

Air

Openings

Figure 1. Closet Installation.

MIN

2

(51)

6

(152)

2

(51)

5

(127)

(584)

23

TOP

VIEW

SIDE

VIEW

Dimensions in
inches (mm).

3. If the boiler is to be installed in a garage, all
burners and burner ignition devices must have a
minimum 18" (457mm) clearance above the floor.

4. The Model JVi-50 through JVi-225 boilers can
be installed in a closet as long as the minimum
clearances shown in Table 4 are observed.
Special attention should be paid to clearances
between the front of the boiler and the closet
door when it is closed (see Figure 1).

Caution

Do not install this boiler in a location subject to
negative pressure, or improper operation will occur.

Boiler
Sizes:

50 to

*1" (25mm) clearance using Type B double wall vent pipe.

Left Right

Side Side

2" 5" 2" 4" 6" 23"

51mm 127mm 51mm 102mm 152mm 584mm

225

Table 4. Minimum Boiler Clearances

From Combustible Surfaces.

Rear Front Flue* Top

5. All boilers are designed and certified for

installation on a combustible floor. Ensure that the
boiler is level from all sides. NEVER store objects on
or around the boiler. Boilers must NEVER be installed
on carpeting.

1F. Gas Supply and Piping

Review the following instructions before

proceeding with the installation.

1. Verify that the boiler is fitted for the proper type
of gas by checking the rating plate. Laars boilers

Mini-Therm JVi

Page 5

are normally equipped to operate below a 2000'
(610m) altitude. Boilers equipped to operate at
higher altitudes have appropriate stickers or tags
attached next to the rating plate.

2. Use the figures in Table 5 to provide adequate
gas piping from the gas meter to the boiler.

3. A trap (drip leg) must be provided ahead of the
gas controls (see Figure 3). A manual gas shutoff
valve approximately 5' (1.5m) above the floor
must also be provided for service, convenience
and safety. Check the local codes.

4. Disconnect the boiler from the gas supply pipe
before pressure testing the pipe for gas leaks.

5. Provide gas supply pressure to the boiler per
Table 6. The regulator is pre-set at the factory,
and normally requires no further adjustment.

NOTE : The boiler and all other gas appliances

sharing the boiler gas supply line must be firing at
maximum capacity to properly measure the inlet
supply pressure. Low gas pressure could be an
indication of an undersized gas meter and/or
obstructed gas supply line.

Distance
From
Gas
Meter in
Feet (m)

0-50'
(0-15)

50-100'
(15-30)

100-200'
(30-60)

NOTE: These figures are for Natural Gas (.65 Sp. Gr.), and are based
on 1/2" water column pressure drop. Check supply pressure with a
manometer, and local code requirements for variations. For LPG,
reduce pipe diameter one size, but maintain a 1/2" minimum diameter.
A 'normal' number of Tees and elbows have been taken into
allowance.

50 75 100 125 160 225

1/2 3/4 3/4 3/4 1 1
3/4 3/4 3/4 1 1 1-1/4
3/4 1 1 1 1-1/4 1-1/4

Boiler Size

Inches

Table 5. Gas Piping Size.

erusserPsaG

ylppuSmuminiM

erusserP

ylppuSmumixaM

erusserP

saGdlofinaM

erusserP

5.5

9

4

saGlarutaN)PL(enaporP

.C.W.ni

aPk

4.1

2.2

1

.C.W.ni

01

41

9

aPk

5.2

4.3

2.2

Table 6. Gas Pressure Measurement.

6. Before operating the boiler, the complete gas
supply system and all connections must be tested
for leaks using a soap solution.

1G. Combustion Air Supply

The boiler location must provide sufficient air

supply for proper combustion, and ventilation of the
surrounding area as outlined in the latest edition of

TEMPERATURE GAUGE

2.4

(6.1)

25

(635)

REF

INDUCED
DRAFT
BLOWER/
MOTOR

PULL-OUT
GAS
MANIFOLD
BURNER
TRAY

C

B

4

(102)

DIA.

Size A B C

mm

50

75
100
125
160
225

in.

13-3/8
13-3/8
16-7/8
16-7/8
20-3/8
25-5/8

340
340
429
429
518
651

in.

3-1/8
2-1/4
5-3/4
5-1/2
7-1/4

10

Table 7. JVi Dimensions.

TEMP./PRESSURE
GAUGE

mm
79

57
146
140
184
254

(178)

Water

Connection

mm

in.

73

2-7/8

2

2-7/8

2
2
2

7

11.8

(298)

51
73
51
51
51

6

(152)

1-1/4
1-1/4
1-1/4
1-1/4
1-1/4
1-1/4

1-1/4" NPT TEE
2X

DRAIN

Gas

Connection

1/2
1/2
1/2
1/2
1/2
3/4

4.9

(124)

8.9

(226)

A

Figure 2. Dimension Information.

Dimensions in
inches (mm).

18 (457) REF.

24 (610)

REF.

Page 6

LAARS HEATING SYSTEMS

U.S. ANSI standard Z223.1 or in Canada, CAN/CGA­B149.1 or .2, and any local codes that may be
applicable.

In general, these requirements specify that the
boiler rooms which represent confined spaces should
be provided with two permanent air supply openings;
one within 12 inches (305mm) of the ceiling, the other
within 12 inches (305mm) of the floor.

Outside Air Supply: When combustion air is
supplied directly through an outside wall, each
opening should have a minimum free area of one
square inch per 4,000 BTU/h (6 sq. cm per 1.2 kW)
input of the total input rating of all appliances in the
enclosed area.

Inside Air Supply: When combustion is
supplied from inside the building, each opening
should have a minimum free area of one square inch
per 1,000 BTU/h (6 sq. cm per 0.3 kW) input of the
total input rating of all appliances in the enclosed area.
These openings should never be less than 100 square
inches (645 sq. cm).

NOTE: In Canada, follow Canadian Standard,
CAN/CGA-B149 or local codes.

Boiler Size Outside Air Area Inside Air Area

sq. in

50

75
100
125
160
225

*Area indicated is for one of two openings: one at floor level and
one at the ceiling, so the total net f ree area would be double the
figures shown. For special conditions, refer to NFPA54 ANSI
Z223.1. In Canada, refer to the National Standard CAN1-B149.1
or .2, which differs fr om this table.
NOTE: Check with louver manufacturers for Net Free Area of
Louvers. Correct for sc reen resistance to the Net Free Area if a
screen is used.

15
20
25
32
40
60

Table 8. Minimum Recommended

Air Supply to Boiler Room.

sq. cm

97
129
161
206
258
387

sq. in.

100
100
100
125
160
225

sq. cm

645
645
645

807
1032
1452

Exhaust Fans or Vents: Any equipment which

exhausts air from the boiler room can deplete the
combustion air supply or reverse the natural draft
action of venting system. This could cause flue
products to accumulate in the boiler room. Additional
air must be supplied to compensate for such exhaust.

The information in Table 8 is not applicable in
installations where exhaust fans or blowers of any
type are used. Such installations must be designed by
qualified engineers.

If a blower or fan is used to supply air to the
boiler room, the installer should make sure it does not
create drafts which could cause nuisance shutdowns. If
a blower is necessary to provide adequate combustion
air to the boiler, a suitable switch or equivalent must
be wired into the boiler control circuit to prevent the
boiler from firing unless the blower is operating.

The boiler must be completely isolated and
protected from any source of corrosive chemical
fumes such as those emitted by trichloroethylene,
perchloroethylene, chlorine, etc.

1H. VENTING

WARNING

This boiler must be vented in accordance with Part
7, Venting of Equipment, of the latest edition of the
National Fuel Gas code, ANSI Z223.1 and all
applicable local building codes. In Canada, follow
CAN/CGA B149 Installation codes. Improper
venting of this appliance can result in excessive
levels of carbon monoxide which can result in
severe personal injury or death!

The boiler vent collar must be fastened directly
to an unobstructed vent pipe of the same diameter with
rustproof sheet metal screws no longer than 1/2"
(13mm) and located to prevent interference with the
inducer damper.

DROP

HORIZONTAL

TO BOILER

3" (76mm)

MIN.

SEDIMENT TRAP
OR DRIP LEG

Figure 3. Gas Supply Piping.

SEDIMENT TRAP
OR DRIP LEG

RISER

TO BOILER

3" (76mm)

MIN.

Mini-Therm JVi

Page 7

Do not weld the vent pipe to the boiler collar.
The weight of the stack must not rest on the boiler.
The boiler top must be easily removable for normal
boiler service and inspection.

Avoid terminating boiler vents near air
conditioning or air supply fans. The fans can pick up
exhaust flue products from the boiler and return them
to the building, creating a possible health hazard.

Avoid oversized vent pipe or extremely long
runs of the pipe, which may cause excessive cooling
and condensation.

1H-1. Vertical Venting - Category I

The Mini-Therm JVi series boiler can be vented
into a masonry chimney, (see Figure 4) provided
several conditions are met:

1. The chimney must have an appropriate tile lining

that is clean, properly constructed and properly

sized.

2. The chimney passage way shall be examined to

ascertain that it is clear and free of obstructions.

3. If a chimney rebuild is required, it shall conform

to nationally recognized standards (see National

Building Code or ANSI/NFPA 211).

4. The boiler must not be connected to a fireplace,

wood stove or other solid fuel burning

equipment.

5. When the boiler and a hot water heater are to be

connected to the same chimney, they must have

their own vent connector and enter the chimney

at least 6" (152mm) apart.

(a) Vent Connections

Use type B double wall or type C single wall (26
gauge, minimum thickness), gas vent pipe from the
boiler to the chimney. Installation of a riser, with a

minimum 12" (305mm) height above the boiler, is
recommended. The vent system should be sloped up
toward the chimney 1/4" per foot (20mm per meter).
The vent connector must be supported for the design
and weight of the material employed, to maintain
clearances and prevent physical damage and
separation of joints.

IMPORTANT NOTE: Always provide a

minimum clearance of 6" (152mm) between Type C
(single wall) vent pipe and any combustible materials.

WARNING

Single wall vent pipe must NEVER pass through
interior walls or through floors or ceilings! Failure to
comply with this warning could result in a fire
causing property damage, personal injury, or death!

When installing the vent system all applicable
national and local codes must be followed! The use of
thimbles, firestops and other protective devices, when
penetrating combustible or noncombustible
construction, must be in accordance with all applicable
national and local codes.

Vertical vents of the induced draft JVi boilers
must be installed in accordance with the code
requirement for Category 1, Fan Assisted Appliances.
Follow the requirements as indicated in the latest
edition of ANSI Z223.1/NFPA 54, sizing of Category
I Venting System and Appendix G, or in Canada,
follow the instruction of CAN/CGA-B149 installation
code.

An unused lined chimney can be used as a
raceway for single wall vent pipe, (see Figure 5).
Never run vent pipe through a flue that has another
appliance attached to it.

CHIMNEY

LINER

THIMBLE

CLEANOUT

Figure 4. Chimney Venting. Figure 5. Vertical Venting.

(20mm PER M)

1/4"

PER FT.

SLOPE

VENT

SYSTEM

BOILER

CHIMNEY

LINER

THIMBLE

CLEANOUT

1/4"

PER FT.

(20mm PER M)

SLOPE

VENT

SYSTEM

12" (305mm)

BOILER

Page 8

10 (3.0) OR

LESS

LAARS HEATING SYSTEMS

MORE THAN 10

(3.0)

RIDGE

2 (0.6) MIN.

WALL OR

PARAPET

CHIMNEY

10 (3.0)

OR LESS

2 (0.6)

MIN.

CHIMNEY

3 (0.9)

MIN.

TERMINATION

10 FT. (3.0m)

OR LESS FROM RIDGE,

WALL OR PARAPET

3 (0.9)

MIN.

Dimensions in feet (m).

Figure 6. Vertical Vent Termination.

(b) Vent Termination

A listed vent terminal designed for the type of
pipe being used must complete the vertical run where
it exits the chimney. The vent pipe must extend at
least 3' (.9m) above the highest point where it passed
through the roof. In addition, the vent cap must be at
least 2' (.6m) higher than any portion of a building
within a horizontal distance of 10' (3m). Clearance to
any combustible materials must be maintained as
listed (see Figure 6).

3 (0.9)

MIN.

WALL OR

PARAPET

NOTE: NO HEIGHT
ABOVE PARAPET
REQUIRED WHEN
FROM WALLS OR
PARAPET IS MORE
THAN 10 FT. (3.0m)

CHIMNEY

RIDGE

MORE THAN 10

(3.0)

2 (0.6)

MIN.

CHIMNEY

10 (3.0)

3 (0.9)

MIN.

For best results, horizontal vent systems should
be as short and straight as possible. Material of vent
connectors shall be as follows:

Materials Vent Length

In U.S.A.: UL type 304, 316 Up to a maximum of 55' (17m)

or 294-C stainless steel, of equivalent pipe run
26 gauge minimum. (including required elbows).
In Canada: Use “BH” vent
type complying with ULC
S-636 Standard.

1H-2. Horizontal Venting - Category III

When venting is horizontal, or cannot meet the
requirements of Category I, it can develop positive
pressure and must be installed in accordance with this
section and the specific vent manufacturer’s
instructions.

Description Manufacturer Product

High Temperature

RTV

2" (51mm) wide

Aluminum foil tape

- adhesively backed
2" (51mm) wide

Aluminum foil tape

- adhesively backed

Dow Corning Trade mate

Venture Product #3243

3M Product #433

Table 9. Vent Sealing Materials.

(a) Vent Connections

The vent system

must be gas tight. All seams and
joints must be sealed with silicone sealant or adhesive
tape having a minimum temperature rating of 400°F
(204ºC) (see Table 9 for a list of approved sealing
materials). Use at least three corrosion resistant screws
at each slip joint, when required.

The boiler vent collar must be fastened to the
vent pipe of the same diameter, with rustproof metal
screws no longer than 1/2" (13mm) and sealed with
high temperature (500ºF / 260ºC) silicone sealant. For
larger diameter vent pipes, use a sealed reducer
fastened directly to the boiler collar and seal all joints
as indicated in Figure 7. Allow the sealant to cure for
24 hours before operating the boiler.

The entire vent system must not exceed the size
specified in Table 10.

The following criteria must be observed:

1. Attach a vertical pipe at least 12" (305mm) high

to the boiler outlet before the horizontal run if

run exceeds 5 feet (see Figure 7).

2. Support the vent run at 3' (.9m) intervals with

overhead hangers.

eziS

522
522

For each elbow eliminated, add 5' (1.5m) of allowable vent.

.ni

4

061-05

4
6

retemaiD

mm

201
201
251

Table 10. Horizontal Venting Configuration.

fo.oN

swoblE

4
2
4

.tf
53
01
53

m

7.01

0.3

7.01

htgneLnuRlatnoziroH

Mini-Therm JVi

Page 9

3. Pitch down the vent run, toward the vent
terminal (hood), 1/4" per foot (20mm per meter).

4. Do not locate any joint screws at the bottom of
the vent run.

(b) Vent Termination

The side wall vent terminal (hood), Laars Part

Number D2004300 (4") or D2000401 (6"), must be
used when the boiler is vented through a side wall. It
provides a means of installing vent pipe through the
building wall, and must be located in accordance with
ANSI Z223.1/NFPA 54, or in Canada CAN/CGA­B149 and local applicable codes, (see Figure 8 ).

BOILER VENTING

DETAIL

OUTSIDE WALL

VENT

SYSTEM

THIMBLE

BOILER

VENT TERMINAL

HOOD

Figure 7. Horizontal Venting.

SHEET METAL

SCREWS

12" (305mm)

*

MIN.

CAULK ENTIRE

JOINT, INCLUDING

THE SCREWS

*WHEN HORIZONTAL RUN

EXCEEDS 5 FT. (1.5m)

Locate the vent terminal so that it cannot be
blocked by snow. Most codes requires termination of
at least 12" (305mm) above grade, but the installer
may determine it should be higher depending on local
conditions.

1H-3. Common Venting System

When an existing boiler is removed from a
common venting system, the common venting system
is likely to be too large for proper venting of the
appliances remaining connected to it.

At the time of removal of an existing boiler, the
following steps shall be followed with each appliance
remaining connected to the common venting system
placed in operation, while the other appliances
remaining connected to the common venting system
are not in operation.

1. Seal any unused openings in the common

venting system.

2. Visually inspect the venting system for proper

size and horizontal pitch and determine there is

no blockage or restriction, leakage, corrosion or

other deficiencies which could cause an unsafe

condition.

3. Insofar as it is practical, close all building doors

and windows and all doors between the space in

which the appliances remaining connected to the

common venting system are located and other

spaces of the building. Turn on clothes dryers

and any gas burning appliance not connected to

the common venting system. Turn bathroom

exhausts, so they will operate at maximum

4 (1.2)

MIN.

VENT

TERMINAL

Dimensions in
feet (m).

Figure 8. Horizontal Vent Termination.

12 (3.7)

MIN.

4 (1.2)

MIN.

VENT TERMINAL

3 (0.9)

MIN.

VENT TERMINAL

LESS THAN

(3.0)

FORCED

AIR INLET

10

6 (1.8) MIN.

GRADE

CAULK JOINTS

ANCHORED

FASTENER

THIMBLE

SHEET METAL

SCREWS

SEAL ENTIRE

CIRCUMFERENCE

OF JOINT

CAULK JOINTS

ANCHORED

FASTENER

EXHAUST

HOOD

VENT TERMINAL DETAIL