Laars JV User Manual
Installation and Operation Instructions Document 1025W
Installation
and Operation
Instructions for
Mini-Therm II
Residential
Gas-Fired
Hydronic Boilers
Model JV
Sizes 50-225
Vent damper is optional in some provinces of Canada.
These instructions are to be stored in the packet provided on the boiler.
FOR YOUR SAFETY: This product must be installed and serviced by a professional service technician,
qualified in hot water 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.
H0071400W
Page 2
LAARS HEATING SYSTEMS
TABLE OF CONTENTS
SECTION 1.
General Information
1A. Introduction...................................................3
1B. Warranty....................................................... 3
1C. Field Assembly.............................................3
1D. Flow Requirements ......................................4
1E. Boiler Placement ..........................................4
1F. Gas Supply and Piping .................................5
1G. Combustion Air Supply.................................6
1H. Venting ......................................................... 7
1H-1. Common Venting System............................. 8
1I. Water Piping of Boiler System...................... 8
1I-1. By-pass Piping ............................................. 8
1J. Chilled Water Systems ...............................10
1K. Electrical Wiring.......................................... 10
1L. Filling the System ....................................... 12
SECTION 2.
Installation Instructions
2A-1. System Start-up.......................................... 14
2A-2. High Altitude Burner
Air Shutter Replacement ............................ 15
2A-3. Sequence of Operation ..............................16
2B. Water Temperature Setting ........................16
2C. Maintenance ............................................... 16
2D. Electrical Troubleshooting .......................... 17
SECTION 3.
Parts List .................................................... 21
Mini-Therm II Hydronic Boiler
Page 3
SECTION 1.
General Information
WARNING
The JV 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/CGAB149.1 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 diverter 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 Laars
Model JV copper tube hydronic boilers. These boilers
are available in two configurations; the JVT has a
thermocouple/continuous burning pilot, and the JVS
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 in the right
rear corner. If the unit is part of a Mini-Combo II
(model MC) Residential Gas-Fired Space/Water
Heater, refer also to Document 8001, Mini-Combo II
Installation and Operation Instructions.
The Laars automatic vent dampers are standard
on all U.S. models. The Laars side wall power venters
can be used on both JVS and JVT models. Special
instructions for their installation are included in the
vent damper and power venter package. Read them
carefully before installation.
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.
Some accessory items are shipped in separate
packages. Verify receipt of all packages listed on the
packing slip. Inspect everything 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. Field Assembly
1. Mini-Therm II boilers have built-in draft diverter
for natural draft operation.
2. Find the vent damper box which is located in the
boiler package (vent damper is optional in
Canada).
3. Install the vent damper directly to the top of the
draft diverter outlet with the damper operator
facing to the front of the boiler, and with the
flow direction arrow pointing upward. Use the
vent damper wire harness provided with the
boiler to connect the vent damper to the boiler.
The bracket end of the harness should be
connected to the vent damper actuator.
4. For Model JVS only: Install the metal plug
provided with the vent damper onto the damper
plate hole. Disregard the metal plug in case of
standing (continuous) pilot boilers. The damper
plate hole should never be blocked on all JVT
models.
Vent
Damper
Vent
Damper
Harness
(optional in
Canada)
Draft
Diverter
(built-in)
1B. Warranty
The Laars Model JV boilers are covered by a
limited warranty. 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.
Figure 1. Vent Damper Installation.
Page 4
LAARS HEATING SYSTEMS
5. The field assembly is now complete. The boiler
is ready for water, gas and electrical connections
and venting installation.
6. Do not modify the automatic vent damper
device. It is very important that no other vents
are closed. Provide at least six inches clearance
between the automatic vent damper and
combustible construction, and be sure to allow
access for servicing the damper.
Caution
Do not force motor operation when operator is
fastened to the damper by moving the damper
blade, turning the shaft or by turning the position
indicator.
Note: In Canada, the vent damper is optional.
1D. Flow Requirements
All high recovery, low volume water boilers
must have adequate flow for efficient operation. Pump
selection is critical to this goal, and pumps should be
selected to provide for system design water
temperature rise. Table 1 details temperature rise and
water flow (GPM) for the Mini-Therm boilers.
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 and outlet. For example: For a JV-100
installation, the inlet water temperature is 160°F
(71°C), and the outlet temperature is 180°F (82°C).
That means there is a 20° (-7°C) temperature rise
through the boiler. According to Table 1, that would
indicate a flow rate of 8 GPM (0.5L/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 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 is being used, and the total
length of piping in the system. Table 2 can help in
making that determination.
1E. Boiler Placement
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.
At least 15" (381mm) access must be available in
front of the boiler for burner removal. Consult local
codes for clearances to hot water pipes and
accessories.
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.
The Model JV-50 through JV-100 boilers can be
installed in a closet, as long as the minimum
clearances shown in Table 3 are observed. Special
attention should be paid to clearances between the
front of the boiler and the closet door when it is
closed.
Consult the American National Standard Z21.13
for more information concerning closet installations.
In Canada, refer to the latest edition of CAN/CGAB149.1 and 2.
IMPORTANT: The boiler shall be installed on
a floor of non-combustible construction with noncombustible flooring and surface finish and with no
combustible materials against the underside, or on
fire-resistant slabs or arches having no combustible
materials against the underside unless listed for
installation on a combustible floor.
All boilers must be installed on a noncombustible surface. That means a surface not capable
of being ignited and burning, such as surfaces
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 boilerin feet 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.
m
0.1
0.2
0.4
0.7
0.8
1.5
gpm
4.0
6.0
8.0
10.0
12.8
18.0
Table 1. Temperature Rise °F °C.
11°C
20°F
l/s
0.3
0.4
0.5
0.6
0.8
1.1
m = Pressure drop (headloss) through the boiler in meters of water.
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
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
Mini-Therm II Hydronic Boiler
Page 5
consisting entirely of a combination of steel, iron,
brick, tile, concrete, slate, glass or plaster.
All boilers can be installed on a combustible
floor if a non-combustible base assembly, available
from Laars, is used. See the boiler rating plate for the
appropriate base part number. Boilers must never be
installed on carpeting.
1/2" Pipe 3/4" Pipe 1" Pipe 1-1/4" Pipe
Size
Pump H.P. Pump H.P. Pump H.P. 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 (-1°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/
12, Grundfos UP26-42F, or equivalent. 1/
HV, Grundfos UP43-75, or equivalent.
Table 2. Maximum Suggested Circuit Length in Feet.
Boiler Sizes 50-125 160-225
Clearances in
Left side 6
Right side 6
Rear 6
Front 4
Flue 6
Top 23
mm
152
152
152
102
152
484
Table 3. Minimum Boiler Clearances
From Combustible Surfaces.
HP=B&G LR-
12
HP=B&G series
6
in
6
6
6
6
6
36
mm
152
152
152
152
152
914
As an alternative to the Laars non-combustible
base plate, the National Fuel Code allows a boiler to
be placed on other than a non-combustible surface
when such an installation complies with the American
Insurance Code. This code specifies the surface under
the boiler be protected with hollow masonry no less
than 4" (102mm) thick, covered with sheet metal at
least 24 ga. in thickness. Such masonry must be laid
with ends unsealed, and joints matched in such a way
as to provide a free circulation of air from side to side
through the masonry (see Figure 3).
12" Min.
(305mm)
12"
Min.
Hollow
Sheet Metal Cover
Sheet Metal Cover
Min. Thickness 24 Gauge
Min. Thickness 24
Galvanized
Gauge Galvanized
Hollow
Concrete
Concrete
Block
Block
Figure 3. Typical Combustible Floor Installation.
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 are normally equipped
to operate below a 2000 foot 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 4 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 4). A manual gas shutoff
valve must also be provided for service
convenience and safety. Check the local codes.
6 (152)
4*
(102)
6 (152)
Dimensions in inches (mm).
*6" for models JV160 to JV225.
6 (152)
Figure 2. Closet and Alcove Installation (see Table 3).
Distance
From Gas
Meter
0-50'
0-15m
50-100'
15-30m
100-200'
30-60m
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
Pipe Size
Table 4. Gas Piping Sizes.
Page 6
LAARS HEATING SYSTEMS
4. Disconnect the boiler from the gas supply pipe
before pressure testing the pipe for gas leaks.
Provide gas supply pressure to the boiler as
follows:
Inches Water Column Natural Gas Propane (LP)
Minimum 5.5 10
Maximum 9 14
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 undersize gas meter and/or obstructed
gas supply line.
5. The correct burner manifold gas pressure is
stamped on the rating plate. The regulator is preset at the factory, and normally requires no
further adjustment.
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 ANSI standard Z223.1 or in Canada,
CAN/CGA-B149.1 or .2, and any local codes that
may be applicable.
In general, these requirements specify that 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 Area*
Boiler Size
50 15
75 20
100 25
125 32
160 40
225 60
*Area indicated is for one of two openings; one at floor level and
one at the ceiling, so the total net free area would be double the
figures indicated. For special conditions, refer to NFPA54 ANSI
Z223.1. In Canada refer to the National Standard CAN1-
B149.1 or .2 which differs from this table.
NOTE: Check with louver manufacturers for Net Free Area of
louvers. Correct for screen resistance to the Net Free Area if a
screen is installed. Check all local codes applicable to
combustion air.
Outside Air
Sq. In.
Area in Sq. In.*
sq cm
97
129
161
206
258
387
Table 5. Minimum Recommended
Air Supply to Boiler Room.
Important
See gas line selection chart, Table 4 previous page,
for gas line sizing. In all cases, pipe size is larger
than inlet connection on heater. Run pipe size
shown in chart and reduce at heater inlet.
Inside Air Area*
Inside Air
Sq. In.
Area in Sq. In.* (sq cm)
100 645
100 645
100 645
125 807
160 1032
225 1452
sq cm
Dimensions in inches (mm)
Dimensions
inches (mm)
Size A B C D E V
50 13-3/8
75 13-3/8
100 16-7/8
125 16-7/8
160 20-3/8
225 25-5/8
340
340
429
429
518
651
27-3/4
27-
3/4 705
28-3/4
28-3/4
28-3/4
31-1/2
705
730
730
730
800
23-5/8
24-1/8
24-1/8
23-5/8
23-5/8
23-1/4
600
613
613
600
600
591
21-3/4
21-3/4
22-3/4
22-3/4
22-3/4
23-3/4
552
552
578
578
578
629
26-1/2
27-1/2
27-1/2
27-1/2
27-1/2
27-1/2
673
699
699
699
699
699
Figure 4. Dimensional Information.
Water Gas
Conn. Conn.
in. in.
4
102
5
127
5
127
6
152
6
152
7
178
1-1/4 1/ 2
1-1/4 1/ 2
1-1/4 1/ 2
1-1/4 1/ 2
1-1/4 1/ 2
1-1/4 *3/4*
*1/2 for propane
Mini-Therm II Hydronic Boiler
Page 7
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 (1.2kW) 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 (0.3kW) 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-B149.1, .2 or local codes.
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 the 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 5 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 of
the pilot. 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 trichlorethylene,
perchlorethylene, chlorine, etc.
1H. Venting
The draft diverter outlet is to be connected to an
unobstructed vent pipe of the same or larger diameter,
terminating outside the building. The vent pipe must
have a listed vent cap, and extend at least two feet
above any object within a ten foot radius. All
connections should be made with rustproof sheet
metal screws.
IMPORTANT NOTE: Do not use sheet metal
screws at the snap lock joints of Type B gas vents.
Do not weld or fasten the vent pipe to the boiler
draft diverter. The weight of the stack must not rest on
the boiler.
easily removable for normal boiler service and
inspection.
elbows, reductions and restrictions. Horizontal runs
should have at least a 1/4" rise per foot (20mm per
meter) in the direction of flow. A vent connector shall
be supported for the design and weight of the material
employed to maintain clearances and prevent physical
damage and separation of joints.
conditioning or air supply fans. The fans can pick up
exhaust flue products from the boiler and return them
inside the building, creating a possible health hazard.
when used as a chimney (Type B or equivalent). In
cold weather, uninsulated outside vents can chill the
rising flue products, blocking the natural draft action
of the venting system. This can create a health hazard
by spilling flue products into the boiler room. Use
engineered venting tables acceptable to the authority
having jurisdiction to size the venting pipe or liner.
runs of the pipe which may cause excessive cooling
and condensation.
The draft diverter and boiler top must be
Avoid horizontal runs of the vent pipe, and 90°
Avoid terminating boiler vents near air
Always use double-wall or insulated vent pipe
Avoid oversize vent piping or extremely long
Figure 5. Vent Pipe Sizing.
Rule of Thumb: The total length of the vent,
including the connector and any offset, should not
exceed 15 feet (4.6m) for every inch (25mm) of vent
diameter (see Figure 5). Longer total lengths shown in
venting tables are based on maximum capacity, not
condensation factors.
Before connecting a vent connector to a
chimney, the chimney passageway shall be examined
to ascertain that it is clear and free of obstructions.
When inspection reveals that an existing chimney is
not safe for the intended application, it shall be rebuilt
to conform to nationally recognized standards (see
National Building Code or ANSI/NFPA 211), lined or
relined with a suitable liner, or replaced with a vent or
chimney suitable for the equipment to be attached.
Page 8
LAARS HEATING SYSTEMS
1H-1. 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 and
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 appliance not connected to the common
venting system. Turn on any exhaust fans, such
as range hoods and bathroom exhausts, so they
will operate at maximum speed. Do not operate a
summer exhaust fan. Close fireplace dampers.
4. Place in operation the appliance being inspected.
Follow the lighting instructions. Adjust
thermostat so appliance will operate
continuously.
5. Test for spillage at the draft hood relief opening
after 5 minutes of main burner operation. Use the
flame of a match or candle, or smoke from a
cigarette, cigar or pipe.
6. After it has been determined that each appliance
remaining connected to the common venting
system properly vents when tested as outlined
above, return doors, windows, exhaust fans,
fireplace dampers and any other gas burning
appliance to their previous conditions of use.
7. Any improper operation of the common venting
system should be corrected so the installation
conforms with the National Fuel Gas Code,
ANSI Z223.1. When resizing any portion of the
common venting system, the common venting
system should be resized to approach the
minimum size as determined using the
appropriate tables in Appendix G in the National
Fuel Gas Code, ANSI Z223.1.
1I. Water Piping of Boiler System
Figure 5 shows ‘typical’ plumbing installations.
Be sure to provide unions and gate valves at the
boiler inlet and outlet so it can be isolated for service.
Check local codes for specific plumbing requirements
before beginning the installation.
An ASME pressure relief valve is supplied on all
JV boilers, and is pre-set at 30 PSI. The valve outlet
piping must discharge to a drain. Under no
circumstances should the relief valve piping be a
closed circuit.
A pressure reducing valve (automatic feed) must
be used to maintain system at constant proper pressure
(see Figure 6). Supply properly installed purge valves
to eliminate air from each circuit.
A drain valve is supplied with the boiler, and can
be found in the plastic bag shipped with each boiler.
This valve is to be installed on the lower right side of
the boiler, see Figure 4, and is used for draining the
unit. To drain the boiler completely, open the drain
valve and remove the two drain plugs located on
the lower left side of the boiler.
Be sure to include air vent devices located at the
highest point in the system to eliminate trapped air,
and an air elimination device near the outlet side of
the JV boiler. Manual vent valves are recommended.
Hot water piping should be supported by suitable
hangers or floor stands, NOT by the boiler. Due to
expansion and contraction of copper pipe,
consideration should be given to the type of hangers
used. Rigid hangers could transmit noise through the
system caused by the piping sliding in the hangers. It
is recommended that padding be used when rigid
hangers are installed.
Gas piping should also be supported by suitable
hangers or floor stands, not the boiler.
A properly sized expansion tank must be
included in the system. Laars offers an aircharged
diaphragm-type expansion tank, with an automatic
feed valve, which includes a pressure regulator set at
12 psig. The part numbers are:
Less Than 20 Gallons in System A0066800
20 to 45 Gallons in System A0066900
1I-1. By-pass Piping
The following information and suggestions are
made on by-pass piping as it affects the temperature
rise at the boiler. A boiler temperature rise must be
taken on all JV boiler installations. If the temperature
rise exceeds 30°F (-1°C), it is an indication that the
boiler is not receiving adequate water flow. Check the
pump for any obstruction, replace the pump with a
larger size where necessary, or install a system bypass as indicated in Figures 6 and 7.
On JV sizes 125, 160 and 225 with a multiple
zone system, a by-pass is required to ensure proper
flow in addition to properly sized circulator and piping
system.
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