Bosch Appliances GWH 260 PN/HN2 Water Heater User Manual


 
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Applications manual
Application manual | 11.2007
Bosch Water Heating
2.6 Bosch GWH 450 ESR
Features:
Speci cally designed for recirculating applications
Electronic ignition and built in power vent
GWH 450 ESR thermal ef 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
GWH 450 ESR Technical Speci cations
Gas input GWH 450 ESR: 45,000 - 120,000 Btu/h
Maximum ow rates GWH 450 ESR: 4.5gpm @ 45°F rise
Thermal Ef 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 Speci cations
Gas connection ¾" Male NPT
Water connections ¾" Male NPT
NG gas pressure Minimum: 5.5" W.C.
Maximum: 14" W.C.
LP gas pressure Minimum: 11" W.C.
Maximum: 14" W.C.
Electrical supply 120VAC - plugs in
Venting 3" stainless steel (AL29-4C)
direct vent
room-sealed combustion
GWH 450 ESR Installation Clearances
Top (A) 12"
Front (B) 1"
Back 0"
Sides 1"
Floor (C) 12"
Fig. 1 Venting con 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 horizon-
tal 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 for isolation valves.
Partially ll condensate drain tube loop with water prior to start
up.