Venting The Heater - Bosch 125FX LP Installation And Operating Instructions Manual

13 ¼"
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.
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.
6
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-
WALL STUDS
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
SUPPORT BOARD
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.
1" X 4"
SPACE BOARD
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
- Horizontal sections of vent connectors must rise ¼"
SCREWS
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.
hangers.
for every foot of horizontal length. Any vent section
greater than 45 degrees from vertical is considered
horizontal.