LAARS MV2 User Manual

Installation and Operation Instructions Document 4126D

Installation and
Operation Instructions for

Mighty Venter
Power Vent System

Models MV1 and MV2 for
Mighty Therm Sizes 175-400

FOR YOUR SAFETY: This product must be installed and serviced by a professional service technician,
qualified in hot water boiler and vent system 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.

WHA T 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.

H0168800D

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LAARS Heating Systems

TABLE OF CONTENTS

SECTION 1.

1a. General Information......................................3

1b. Vent Sizing ...................................................3

1c. Inspection and Unpacking ............................ 3

1d. Installer Information ...................................... 3

1e. Installation Restrictions.................................4

SECTION 2.
Side Wall Vent Hood Location

2a. Side Wall Vent Hood Location ...................... 4

SECTION 3.
Electrical Wiring

3a. Safety Interlock Test.....................................8

3b. Maintenance ................................................. 8

Mighty Venter Power Vent System

Page 3

SECTION 1.
1a. General Information

WARNING

The MV1 and MV2 Mighty Venter must be installed
in accordance with the procedures outlined in these
instructions. Warranty applies only if the installation
and operating instructions applicable to the model
purchased are expressly and completely followed.

The Laars Mighty Venter, Models MV1 and
MV2, are designed to make side-wall venting possible
for Laars hot water boilers, Models HH, PH, VW and
PW, sizes 175 - 400. Both the MV1 and MV2 are
equipped with a fan-prover switch which disables the
gas valve if the Power Venter fails to operate.

The Mighty Venter installation must comply with
the latest edition of the National Fuel Gas Code, ANSI
Z223.1, and in Canada, CAN1-B149.1 or .2 and all
local codes that apply. The installation must include
the draft hood assembly shipped with the boiler,
including vent damper if required.

1b. V ent Sizing

Take into consideration the dimensions in Table 1
when designing the vent system. The vent pipe length
shown includes all vent pipe before and after the
Power Venter.

The Mighty Venter kit includes three cartons:
Carton 1. Power Venter (MV1 or MV2)

Carton 2. Vent Hood
Carton 3. Vent Reducers/Adapter

Verify the contents of each carton by checking

against the parts list on page 8.

1d. Installer Information

1. Before beginning the installation, read these
instructions completely and make sure each part
is placed to safely vent flue gases to the
outdoors.

2. Carefully read the installation instructions
located in the Side Wall Vent Hood carton.

3. Laars does not provide the vent pipe necessary
for this installation. Use Table 1 as an aid in
selecting the proper vent pipe diameter.

4. Locate the Power Venter as close as possible to
the point of termination (i.e., the wall). This will

insure the vent pipe between the boiler and the
Power Venter inlet is under negative pressure.

5. Make sure the power supply is adequate for the
Power Venter motor requirements. Do not add
the Power Venter to a circuit where the total load
is unknown.

1c. Inspection and Unpacking

Immediately upon receiving the Mighty Venter
kit, inspect the shipment packaging for damage.
Record any damage on the shipping documents.

To prevent personal injury and equipment damage,
disconnect the power supply to the hot water boiler
when working on the Power Venter.

Caution

Unpack the equipment and carefully inspect it for
obvious damage caused in shipment. If any damage is
found, YOU must file a claim with the transporter. The
transporter will not accept a claim from the shipper,
Laars Heating Systems.

Mighty Boiler/ Mighty Venter Boiler/Heater Vent Pipe Equivalent Equivalent Mighty Venter
Venter Heater Order Number Outlet Diameter Diameter Pipe Length Pipe Length Diameter

Model Size in mm in. mm feet m feet m in mm

MV1 175 10718702 6 152 4 102 11 3.4 90 27.4 4 102
MV1 250 10718703 7 178 6 152 11 3.4 100 30.5 4 102
MV2 325 10718704 8 203 6 152 11 3.4 100 30.5 6 152
MV2 400 10718705 9 229 6 152 11 3.4 100 30.5 6 152

Notes:

1. Table 1 is for single boiler installations only.

2. To calculate the equivalent vent pipe length, add the length of the straight pipe plus 10 feet (3.0m) for every
90° elbow and 5 feet (1.5m) for every 45° elbow.

3. Vent pipe reducers will be supplied by Laars.

Minimum Maximum

Table 1. Critical Vent Sizing Data.

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LAARS Heating Systems

1e. Installation Restrictions

1. Make sure minimum clearances from
combustible materials required by code are
maintained.

IMPORTANT: The following clearances to

combustible materials must be maintained for the
Power Venter:

Sides: 6-inches (152mm)
Back: 8-inches (203mm)

2. All vent pipe connections between the Power
Venter and the Vent Hood will be under positive
pressure during operation, and must be sealed to
prevent leakage into the building.

3. To prevent bearing wear, and for proper Fan­Prover Switch operation, make sure the Power
Venter motor shaft is horizontal (see Fig. 1).

4. The ambient temperature surrounding the Power
Venter must not exceed 104°F (40°C).

5. The venting system must be sloped upwards not
less than 1/4 inch per foot from the boiler to the
vent terminal. The vent system must be installed
to prevent the collection of condensate where
necessary, and must be provided with a means of
drainage.

6. Condensate lines or single wall exhaust vent
shall not be run through an unheated space or
interior part of an open chimney unless the
exhaust vent is insulated.

7. The vent system must be adequately supported to
prevent sagging, but in no case shall the supports
be less than every 3 feet (0.9m).

8. Inlet and outlet piping must conform to Figure 4,
5 or 6.

9. Do not place any elbows within two feet of
venter outlet.

SECTION 2.

2a. Side Wall Vent Hood Location

If possible, locate the side wall vent hood on a

wall not normally subjected to high winds. This will
lessen the possibility of gas valve interruption during
periods when the winds are stronger than 40 MPH
(64 kmh). The Vent Hood location must comply with
the following specifications (see Fig. 2):

Caution

Flue gas temperature can exceed 150°F (66°C)
depending on the appliance being vented and the
length of the vent system. Do not terminate a side
wall vent system where vinyl siding has been
installed on the building exterior, since damage to
the vinyl siding may result.

Horizontal Discharge Vertical Discharge

Figure 1. Discharge Options.

Air Pressure
Sensing Tube