LAARS Mini-Combo id MCH User Manual

Installation and Operation Instructions Document 2101B

Installation

and Operation

Instructions for

Mini-Combo id

Model MCH

Induced Draft

Residential Gas-Fired

Space/Water Heater

Note: This document is to be used in conjunction with Document 1080, Installation and Operating
Instructions for Mini-Therm JVi boilers.

WARNING

Improper installation, adjustment, alteration, service or maintenance can cause injury or property
damage. Refer to this manual. For assistance or additional information consult a qualified installer,
service agency, gas supplier, or call the factory.

H2100200B

Page 2

LAARS Heating Systems

TABLE OF CONTENTS

SECTION 1.
General Information

1A. Hazards and Your Safety —

Hot Water Can Scald!...................................3

SECTION 2.

Installation .................................................

2A. Location........................................................ 5

2B. Heater Placement.........................................5

2C. Piping ........................................................... 5

2D. Wiring ...........................................................6

3

Mini-Combo id

Page 3

SECTION 1.
General Information

WARNING

This manual supplies information on the application,
installation and operation of the indirect water
heater unit.
operation of the hydronic boiler (Document 1080) is
supplied along with this manual. Both manuals
should be reviewed completely before proceeding
with the installation.

• Failure to follow the instructions provided may
result in personal injury, death or substantial
property damage.

• Any modifications to the boiler, water tank, gas
and water connections, or wiring may void
warranty.

• Consult the factory or local factory
representative with any questions or problems
regarding this equipment.

Hazards and Your Safety — Hot Water
Can Scald!

Consumer Product Safety Commission and some

states/provinces recommend a temperature setting of
130°F (54°C) or less. The water heater thermostat is
factory set to approximately 120°F (49°C). If
thermostat will be set above factory setting, install an
anti-scald valve at either the water heater or at each
hot water faucet.

A complete instruction manual of the

• Studies have indicated that dangerous bacteria
can form in potable water distribution system if
certain minimum water temperatures are not
maintained. Contact local health department for
more information.

SECTION 2.
Installation

This installation must conform with the

instructions in this manual and, where applicable:

• Local, state, provincial, and national codes, laws,
regulations and ordinances.

• In Canada — CAN/CGA B149.1 or B149.2
installation Code.

Where the recommendations made in this manual

differ from local or national codes, the local or
national codes take precedence.

2A. Location

This water heater/boiler unit is not intended for

outdoor installation. Select a convenient location
where water leakage from the tank or connections will
not result in damage to areas adjacent to the appliance
or to lower floors of the structure. When a safe
location cannot be found, install a suitable drain pan
under the appliance, and pipe it to an adequate drain.

• Tempering valves are not anti-scald valves since
they do not have a positive shutoff in case cold
water supply fails. They are not recommended
for shower/tub service. If needed, install an anti­scald valve at each shower/tub.

• Water heated to a temperature suitable for
clothes washing, dish washing and other
sanitizing needs can scald and cause permanent
injury.

• Children and elderly, infirm, or physically
handicapped persons are more likely to be
injured by hot water. Never leave them
unattended in a bathtub or shower. Never allow
small children to use a hot water tap or draw
their own bath. If anyone using hot water in the
building fits this description, or if state/province
laws or local codes require certain water
temperature at hot water taps, take special
precautions:

Install an anti-scald valve at water heater or at
each hot water faucet, bath, and shower outlet.

Use lowest practical temperature setting.

2

(51)

63.5

(1613)

Figure 1. Closet Installation.

25.25
(641)

29

(737)

4 (102)

Top Clearance

23 (584)

57.75

(1467)

2 (51)

2

(51)

Dimensions
shown in inches
(mm).

Page 4

Check Valve

Tank

Pump

.75

(19)

24

(610)

Domestic

Hot Water

Outlet

Cold Water

Inlet

32.5

(826)

62.5

(1588)

41.5

(1054)

Tank

Aquastat

Drain
Valve

LAARS Heating Systems

Boiler Flue Collar 4 (102)

60

(1521)

Tank
Relief
Valve

24

(610)

7

(178)

(610)

Figure 2. Dimensional Information.

Dimensions inches mm

Size A

50 14 356

75 15 381
100 16 406
125 17 432

Boiler In/Out NPT

(all sizes) 1¼

Gas NPT (all sizes) ½*
Domestic Hot Water (all sizes)

Inlet/Outlet NPT ¾

Minimum clearances from

combustible surfaces:

Left Side: 2" 51mm

Right Side: 2" 51mm

Rear: 2" 51mm

Front: 4" 102mm Top: 23" 584mm

Service clearances:

Allow 4" 102mm on each side

for piping access.

7

(178)

24

Side View Front View

Hot

Water

Supply

Cold

Water

Supply

28

(711)

Figure 3. Piping Schematic.

Dimensions shown
in inches (mm).

Space Heating -

Refer to Doc u me n t 1 080

Boiler

Tank

*¾" for model 125 Natural.

Figure 4. Typical Expansion Tank Installation.