Bosch Appliances 125FX LP, 125FX NG specifications Venting, Freeze Warning, Spill Switch Safety

WALL STUDS

13 ¼”

SUPPORT BOARD

1” X 4”

SPACE BOARD

Fig. 2 - Mounting the Heater

The incandescent particle tray (shipped loose in the carton with the water heater) must be attached at the bottom of the water heater front cover at the time of installation. Use the screws provided. See figure 3.

SCREWS

INCANDESCENT PARTICLE TRAY

Fig. 3 - Incandescent Particle Tray Illustration

VENTING

WARNING: Do not reduce the vent pipe size. This appliance must be vented horizontally to the outside with sealed 4” single wall vent pipe following all local ordinances and specifications for installing a power vented Category III appliance. The 4” single wall vent pipe can be either stainless steel (AL29-4C) or galvanized vent of at least 26 gauge. Stainless steel is preferred. All connections must be properly sealed. The vent system must be installed by a qualified installer in accordance with all applicable local gas codes. The venting system must be designed and constructed so as to develop a positive flow adequate to remove flue gases to the outdoors.

CAUTION: Aquastar power vent system must be installed by a qualified agency in accordance with these instructions. If improperly installed a hazardous condition such as an explosion or Carbon Monoxide poisoning could result. Controlled Energy Corporation will not be responsible for improperly installed appliances.

Plan the vent system so that code and manufacturer’s clearances are maintained.

The minimum clearance from the top of the heater is 12 inches. Single wall vent pipe when mounted to the 125FX requires a 3-inch clearance from combustibles. In all cases, follow local codes:

-In Canada, CAN/CGA-B149 Installation Code for detailed requirements.

-In USA, ANSI Z223.1 – latest edition, National Fuel Gas Code for detailed.

Minimum vent size diameter must be 4”. The appliance must be located as close as practicable to a vent terminal.

Maximum vent length is 15 feet (4.6m) with two 90- degree elbows. This unit may be directly connected to an approved vent termination with a 90-degree elbow. The vent pipe connections must be secured to each other with a minimum of 4 sheet metal screws per connection, and all seams must be sealed with an approved high temperature silicone sealant and aluminum duct tape. The vent system must be gas tight. See Fig 4 for suggested venting installation diagrams.

For best results, the horizontal vent system should be as short and straight as possible. Vent pipe must be single wall stainless steel (AL29-4C) or galvanized vent pipe of 26 minimum gauge. The maximum allowable horizontal length of vent pipe is 15 feet. 2 elbows are allowable within this maximum vent length. For each additional elbow deduct 5 feet from maximum vent length. Any vertical portion of the vent pipe that is part of the horizontal vent system must be considered part of the allowable 15 foot maximum. When the horizontal vent run exceeds 5 feet the following criteria must be observed:

-Support the vent run at 4-foot intervals with overhead hangers.

-Horizontal sections of vent connectors must rise ¼” for every foot of horizontal length. Any vent section greater than 45 degrees from vertical is considered horizontal.

Note: Single wall vent pipe cannot be used in any concealed locations and should not be used in any unheated space without an insulated chase. Unsealed 5” or 6” size double wall B-Vent may be used as a chase for straight lengths (no elbows) of the 4” single wall vent pipe. All connections of the 4” single wall vent inside the 5” or 6” B-Vent must be properly sealed. A 1” clearance is required from the B-Vent pipe to combustibles.

Freeze Warning:

As mentioned on Page 5, negative air pressure in cold climates will cause a reverse airflow in the vent system that can freeze and damage the Aquastar heat exchanger when not in use. To prevent this the FXHOOD horizontal vent terminator, which was 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.

Spill Switch Safety:

The 125FX is equipped with a Spill Switch; it’s mounted on the left side of the draft diverter (Flue gas safety device - #9 on page 19). Before leaving the installation site verify proper Spill Switch operation by temporarily blocking termination outlet. Once blocked then operate the heater, the unit should shut down within 1-3 minutes when the flue gases are blocked. You must reset the electrical power to the heater after this safety test has been conducted, otherwise the unit will not operate.

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