Bosch Gwh 425 Hn - Bosch GWH 715 ES Applications Manual

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2.8 Bosch GWH 425 HN

Features:
Hydro-generated ignition
80% thermal effi ciency
Endless hot water for one major application at a time
Venting: 5" double wall B-vent — natural draft
Modulating gas valve — constant temperature at varying flow rates
Model GWH 425 HN N for natural gas (NG) supply
Model GWH 425 HN L for liquid propane (LP) supply
15-year warranty on heat exchanger
GWH 425 HN Technical Specifi cations
Gas input
Minimum fl ow to activate
Flow rates
Thermal Effi ciency
Dimensions
Weight
Modulating gas valve
Ignition
Accessories
GWH 425 HN Installation Specifi cations
Gas connection
Water connections
NG gas pressure
LP gas pressure
Water pressure
(Static)
Electrical supply
Vertical venting
Horizontal venting
Application manual | 11.2007
Natural Gas: 30,735 - 117,000 BTU
LP Gas: 30,735 - 117,000 BTU
0.6 gallons per minute (gpm)
45˚F rise @ 4.2 gpm
55˚F rise @ 3.4 gpm
65˚F rise @ 2.9 gpm
77˚F rise @ 2.4 gpm
90˚F rise @ 2.1 gpm
NG: 80% LP: 80%
25.75" h x 16.75" w x 8.5" d
33 lbs.
yes
Hydro-generated
Horizontal vent kit (AQ4) - power
vent kit for horizontal venting
¾" Male NPT
¾" Male NPT
Minimum: 7" W.C.
Maximum: 14" W.C.
Minimum: 11" W.C.
Maximum: 14" W.C.
Minimum: 30 PSI
Minimum well pressure: 40 PSI
Maximum: 150 PSI
120VAC - plugs in
5" minimum diameter - natural
draft
AQ4 horizontal vent kit required
for horizontal terminations
GWH 425 HN Installation Clearances
Top (A) 12"
Front (B) 4"
Back 0"
Sides 4"
Floor (C) 12"
LIS TE D G AS VE NT
E S TA B LIS H A O NE
F O O T R IS E B E F O R E
A NY E LB O W S
Fig. 2 Venting confi guration
Installation guidelines:
Venting:
5" minimum diameter — do not reduce vent size
Refer to installation manual for vent material options
Do not combination vent with any power vented appliances
Establish a one-foot rise before any elbows
Minimum vent height - 6 feet
Horizontal sections must slope upwards at least ¼" for every foot
of the horizontal length and be properly supported
Gas piping:
Heater will not function properly without adequate supply gas
pressure
Any appliance connector should be ¾" minimum diameter
Plumbing:
Install the included pressure relief valve and pipe to suitable drain
Minimum piping diameter is ¾"
Do not solder directly to connections on the bottom of the unit
Use full port ball valves for isolation valves
BOSCH THERMOTECHNOLOGY CORPORATION
Applications manual
LIS TE D VE NT C AP
MINIMUM 6
FE E T (1.8M)