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Caution
• Check if adjacent wall or ceiling is fire resistant and allows safe distance for fire prevention.
• This water heater is suitable for residential water (potable) heating only. Do not use this
water heater for space heating, combination space heating/domestic water heating, or
commercial water heating applications.
• MWH-180EX is not suitable for use in pool or spa applications.
• Maintain proper space around the unit for proper servicing and operation. Minimum
clearances from combustible materials are listed below.
Note : These clearances do not apply if installing unit into an MPI recess box, however
they do apply from the exhaust port to combustible once the exhaust port comes
out of the recess box.
• Do not install MWH-180EX under an overhang less than 3feet from the top of the unit.
When the overhang protrudes out over MWH-180EX greater than 3feet, the area under
the overhang must be open on 3sides.
• When the water heater is installed within a recess box, the clearances from the top, bottom,
sides, and back surfaces of the recess box to combustible materials are 0inch.
The clearance from combustibles from the front of the recess box is 24inches.
• Secure enough space so that the inspection and repairs can be done easily.
• Secure space not only in front but also under the unit.
• Do not install the unit over other combustion appliances such as gas cooking stove or a
range.
Oil residue and dust in the air can adhere to the burner and the heat exchanger resulting in
deformation, loss of efficiency, or damage to electronic components.
• Do not install the exhaust outlet near the outlets of the other appliances.
Install the air inlets away from the wind path as the wind may cause imperfect combustion.
• Do not install the unit where commercial chemicals are used.
Those chemicals are ammonia, sulfur, chloride, ethylene compound and acids which are
used at beauty shop, laundry, factory and so forth.
• Do not install the unit over food or dishes.
• Installer must install a Pressure relief valve.
Pipe pressure relief to a drain or outside environment, or within 4inches of the floor.
Pipe pressure relief discharge to a drain or outside environment. (refer to page 22)
• The appliance should be located in an area where leakage from the unit or connections will
not result in damage to the area adjacent to the appliance or to lower floors of the
structure. When such locations can not be avoided, it is recommended that a suitable drain
pan, adequately drained, be installed under the appliance. The pan must not restrict
combustion airflow.
Top of heater
Front of heater
Sides of heater
Back of heater
Floor
12"
24"
6"
0"
12"
(30.5cm)
(61.0cm)
(15.2cm)
(0cm)
(30.5cm)
