John Wood Takagi - 710 - Manual (Page 6)

6
Bottom 305mm
(12 in.)
Back
25mm
(1 in.)
Front 76mm (4 in.)
(610mm (24 in.)
recommended for service)
Top
305mm (12 in.)
Side
(50mm
(2 in.)
Side
(50mm (2 in.)
Combustion Air Supply
The water heater location must provide enough air for
proper combustion and ventilation of the surrounding area.
See the latest edition of B149.1 or any applicable local
codes. In general, these requirements specify that if the unit
is installed in a confined space, there must be a permanent
air supply opening.
Minimum recommended air supply opening size for water
heater:
Water
heater
size
When drawing
make-up air from
outside the
building
When drawing make-
up air from inside the
building (from other
rooms within)
MAX
240,000
BTU/h
103cm 2 (16.0 in 2 ) 1548cm 2 (240 in 2 )
When combustion
air is supplied from
outside the building,
an opening commu-
nicating directly with
the outside should
have a minimum
free area of 6.5cm
2
(1 in 2 ) per 15,000
BTUH input of the
total input rating of
water heater in the
enclosed area.
When combustion air
is supplied from inside
the building, an open-
ing communicating with
the rest of the dwelling
should have a minimum
free area 6.5cm
2 (1 in 2 )
per 1,000 BTUH input
of the total input rat-
ing of water heater in
the enclosed area. This
opening should never be
less than 1284cm
2 (199
in 2 ).
Combustible Air Supplied by Mechanical fan or Make up air
device
The 710 water heater is equipped with a combustible air
sensor that will shut off the unit when inadequate combus-
tible air supply to unit is detected.
• If a mechanical fan or make up air device is used to
supply air to the water heater or utility room, the installer
should make sure it does not create drafts which could
cause nuisance shutdowns.
• If a blower is necessary to provide adequate combustion
air to the water heater, the blower and water heater must
be set up so that the water heater cannot fire unless the
blower is operating. Possible methods include the use of
external flow sensors/transmitters and relays.
Direct Intake Vent System
This 710 water heater may be converted to a direct-vent
(sealed combustion) appliance by installing an adapter (Part
No. TM-DV32) which will bring all required combustible air
from outside the building. When installing the direct-vent
conversion kit, please follow all instructions included with
the kit.
• The 710 must be installed in a location where the proper
amount of combustible air will be available to it at all
times without obstructions.
• If used as a direct-vent appliance, the 710 requires a
102mm (4 in.) combustible air supply pipe. The intake
pipe must be sealed airtight.
• Air supply pipe can be made of ABS, PVC, galvanized
steel, corrugated aluminum, corrugated stainless steel or
Category III stainless steel.
• Change the DIPswitch settings to the direct-vent system.
(See diagram below)
• Sidewall venting is recommended for the direct-vent sys-
tem.
• The manufacturer recommends running the exhaust vent
and the intake pipe parallel.
• The Direct-Vent Conversion Kit has an “INLET” mark
as shown below. Do not reverse the INLET and the
EXHAUST connections when installing vent pipes.
Make sure power to the unit is turned OFF
before changing the DIPswitch settings.
1
2
3
4
5
6
7
8 TMP1
ON
TMP2
TMP3
MODE
DIRE
OUT
D-PRT
MST
The dark square
is the direction the
DIPswitch should
be set to.
Left bank of
DIPswitches
Left Bank of
DIPswitches
7-Seg LED
Right bank of
DIPswitches
Direct-Vent Conversion Kit