Bosch Gwh 450 Esr - Bosch GWH 345 ESR Applications Manual

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2.2 Bosch GWH 450 ESR

Features:
Specifi cally designed for recirculating applications
Electronic ignition and built in power vent
GWH 450 ESR thermal effi ciency of 81%
Vents vertically or horizontally with 3" stainless steel (AL29-4C)
Direct vent room-sealed combustion
Computerized temperature control — ensures temperature
stability
Model GWH 450 ESR N for natural gas (NG) supply
Model GWH 450 ESR L for liquid propane (LP) supply
10-year warranty on heat exchanger
GWH 450 ESR Technical Specifi cations
Gas input 45,000 - 120,000 Btu/h
Maximum fl ow rates 4.5gpm @ 45°F rise
Thermal Effi ciency 81%
Dimensions 27.5" h x 15.75" w x 11.75" d
Weight 47 lbs.
Modulating gas valve yes
Ignition Electronic
GWH 450 ESR Installation Specifi cations
Gas connection
Water connections
NG gas pressure
LP gas pressure
Electrical supply
Venting
GWH 450 ESR Installation Clearances
Top (A) 12"
Front (B) 1"
Back 0"
Sides 1"
Floor (C) 12"
Application manual | 02.2009
¾" Male NPT
¾" Male NPT
Minimum: 5.5" W.C.
Maximum: 14" W.C.
Minimum: 11" W.C.
Maximum: 14" W.C.
120VAC - plugs in
3" stainless steel (AL29-4C)
direct vent
room-sealed combustion
GWH 345/450 ESR applications manual
Fig. 1 Venting confi gurations
Installation guidelines:
Venting:
Must be 3" or 4" AL29-4C sealed stainless steel vent pipe.
Slope horizontal runs up to termination ¼" per foot. The
horizontal section between last elbow and termination must slope
down to the termination ¼" per foot.
Do not combination vent with any other appliance.
Always install an external condensate drain except when termi-
nating horizontally with less than 3 feet of pipe.
See manual for vent terminator clearances.
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 the bottom of the unit.
Use unions to facilitate easy future maintenance.
Use full port ball valves or isolation valves.
Partially fi ll condensate drain tube loop with water prior
to start up.
BOSCH THERMOTECHNOLOGY CORPORATION