AquaStar 125FX LP, 125FX NG specifications Combustion Air Requirements, Clearances

COMBUSTION AIR REQUIREMENTS

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.

CLEARANCES

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)

Air Vents		* On a combustible wall surface the unit should be mounted
	125FX	away from the wall to provide adequate clearance of the
(10 ¾ X 10 ¾ in. each)

vent pipe. Clearance from the vent pipe is dependent upon the clearance rating of the venting material used. See VENTING section.

125FX Air Vents

(5 ½ X 5 ½ in. each)

6 720 606 601 5