The AquaStar water heater holds cold water in its copper heat exchanger and brass water valve when not in use. Because of this, any cold air that comes in through the unit’s vent pipe is capable of freezing these components. This Installation Manual specifies the vent length requirements and the amount of combustion air required for this unit. When all requirements are followed, the unit will operate properly and safely. However, there may still be a risk of freezing due to negative draft if all the combustion appliances in the area are not being supplied with a sufficient amount of make-up air. A wood stove or furnace can rob the make-up air in the AquaStar’s vent pipe, leaving the cold infiltrating air capable of freezing the cold water in the AquaStar heat exchanger. To prevent this the FXHOOD horizontal vent terminator, which is supplied separately with the water heater, needs to be installed on the end of the horizontal vent run (see page 7). The FXHOOD is a CSA approved vent terminator for the Aquastar 125FX and has a built in back draft flapper.
Observe the following instructions concerning combustion air.
Appliances located in unconfined spaces:
a)An unconfined space is one whose volume is greater than 50 cubic feet per 1000 Btu per hour of the combined rating of all appliances installed in the space. That would be 6500 cubic feet for the AquaStar 125FX alone.
b)In unconfined spaces in buildings of conventional frame, masonry, or metal construction, infiltration is normally adequate to provide air for combustion, ventilation, and dilution of flue gasses.
Appliances located in confined spaces: The confined space must be provided with two permanent openings, one commencing within 12 inches of the top and one commencing within 12 inches of the bottom of the enclosure. Each opening must have a minimum free area of one square inch per:
—1000 Btu/hr if all air is taken from inside the building.
—2000 Btu/hr if all air is taken from the outside by horizontal ducts.
—4000 Btu/hr if all air is taken from the outside by direct openings or vertical ducts.
Or the confined space must be provided with one permanent opening or duct that is within 12 inches of the ceiling of the enclosure. This opening must have a minimum free area of one square inch per:
—3000 Btu/hr if all air is taken from the outside by a direct opening or vertical duct.
Louvers, grills and screens have a blocking effect. If the effective free area is not known, assume it is 20 % to 25% of the total opening for wood louvers and 60 % to 75% for metal louvers. Refer to the National Fuel Gas Code for complete information. In buildings of tight construction all air should be taken from outside.
This product is not approved for manufactured homes (mobile home), recreational vehicles (RV) or boats. Reference ANSI Z21.10.3.
This product is neither designed or approved for outside installations.
The Aquastar 125FX is design certified for installation on a combustible wall and for installation in an alcove or closet with the minimum clearances to combustible and non - combustible construction listed below
A.Top 12 inches (305 mm)
B.Front 4 inches (102 mm)
C.Back 0 inches*
D.Sides 4 inch (102mm)
E.Bottom 12 inches (305 mm)**
*On a combustible wall surface the unit should be mounted away from the wall to provide adequate clearance of the vent pipe. See mounting instructions below.
**Some local codes require 18” in garage installations.
Clearance from vent pipe is dependent upon the clearance rating of the venting material used. Single wall flue pipe should be used and it is approved for 3” clearance for this appliance. NOTE: See mounting instructions below to prop- erly maintain a 3” clearance from the vent pipe to a com- bustible surface.
Note: this clearance can be reduced if combustible material are protected as per table VI of the National Fuel Gas Code.
MOUNTING INSTALLATION
The Aquastar 125FX is design certified for mounting on a wall.
Secure the two L shaped hooks, which are provided with heater, to a wall surface. Place them 13 ¼” apart as shown in Fig 2.
Do not install this appliance on a carpeted wall or over floor covering which is combustible, such as carpet. The heater must be mounted on a wall using appropriate anchoring materials. If wall is a stud wall sheathed with plasterboard, it is recommended that support board(s) either 1x4’s or 1/ 2" (minimum) plywood first be attached across a pair of studs and then the heater should be attached to the support boards. See Fig 2.
NOTE: Additionally the 125FX should be spaced away from any combustible wall surface by a minimum of 1 ½” to provide the needed 3” clearance between the vent pipe and the wall surface. Review the FXHOOD horizontal vent terminator instruction sheet (provided with the FXHOOD) prior to heater installation.
In earthquake-prone zones, CEC recommends that installers use a large washer and lag screw through the existing holes used to hang the heater to affix the upper third of the heater to the mounting board. To affix the lower third of the heater, CEC recommends that two new holes be drilled in the heater’s frame, each one 16 inches below the top two holes, and that washers and lag screws be used to secure the lower portion of the heater to a spacing board.
Expansion and contraction of piping due to changing water temperature in the pipes imparts movement to the heater which, if mounted directly to a brittle, friable board, such as plasterboard, can cause failure of mounting.