Bosch Appliances GWH 425 PN/HN4GWH 4254 Water Heater User Manual


 
Applications manual | 11.2007Bosch Water Heating
Applications manual
| 11
2.7 Bosch GWH 425 EF
Features:
Electronic ignition and built in power vent
Thermal ef ciency of 82%
Vents with 4" stainless steel or galvanized vent pipe
Specifically designed for horizontal vent terminations
Modulating gas valve — ensures temperature
stability
Model GWH 425 EF N for natural gas (NG) supply
Model GWH 425 EF L for liquid propane (LP) supply
15-year warranty
Quali es for $300 tax credit (LP only)
GWH 425 EF Technical Speci cations
Gas input Natural Gas: 28,000 - 130,000 Btu/h
LP Gas: 28,000- 125,000 Btu/h
Minimum ow to
activate
0.5 gallons per minute (GPM)
Maximum ow rates 4.6 gpm @ 45°F rise
Thermal Ef ciency NG: 80% LP: 82%
Dimensions 29.75" h x 18.25" w x 8.75" d
Weight 44 lbs.
Modulating gas valve yes
Ignition Electronic
GWH 425 EF Installation Speci cations
Gas connection ½" Male NPT
Water connections ½" Male NPT
NG gas pressure Minimum: 7" W.C.
Maximum: 14" W.C.
LP gas pressure Minimum: 11" W.C.
Maximum: 14" W.C.
Electrical supply 120VAC - plugs in
Venting 4" stainless steel (AL29-4C)
or 26 gauge galvanized
GWH 425 EF Installation Clearances
Top (A) 12"
Front (B) 4"
Back 0"
Sides 4"
Floor (C) 12"
Fig. 1 Venting con gurations
Installation guidelines:
Venting:
4" AL29-4C sealed stainless steel or 26 gauge galvanized vent
pipe.
Slope horizontal runs up to termination ¼" per foot.
Do not combination vent with any other appliance.
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 ½".
Do not solder directly to connections on the bottom of the unit.
Use full port ball valves for isolation valves.