American Dryer Corp. GWH 425 EF - Manual (Page 3)

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425 EF LP and 425 EF NG Specifications
Water Connection 1/2” Thread fitting NPT
H x W x D 29 3/4” x 18 1/4” x 8 3/4"
Vent 4”
Gas Connection 1/2” NPT thread
Min. Water Pressure 18 Psi
Max. Water Pressure 150 Psi
Shipping Weight 50.6 LB
Net Weight 44 LB
2.3 GPM at 90° rise
4.6 GPM at 45° rise
Min. Water Flow 1/2 gal/min
120V/60Hz 1.2 Amps
LP GAS Supply Pressure min. 11” W.C.
(before 425 EF regulator) max.14” W.C.*
Required LP GAS pressure at inlet
tap while 425 EF is operating:
10.5” W.C.
LP GAS Burner Manifold pressure while
425 EF is operating at maximum input: 9.9” W.C.
Natural Gas Supply Pressure min.: 7” W.C.
(before 425 EF regulator) max.: 14”W.C.*
Required Natural Gas Pressure at
inlet tap while 425 EF is operating:
5.7”W.C.
Natural Gas Burner Manifold pressure while
425 EF is operating at maximum input: 5.38” W.C.
* Inlet gas pressure before 425 EF regulator must not
exceed this value. Pressure may need to be adjusted for
high altitudes, see page 11.
Principle of Operation:
When a hot water faucet is opened, the flow of water through
the heater causes the gas valve to open. At the same time
a microswitch is activated which sends a spark to the pilot.
The flame sensor confirms that the pilot has been lighted
and allows the first two burners to ignite. The flame sensor
confirms correct activation and all burners ignite. The pilot
goes out. The power exhaust system runs as long as the
burners are on. The heat exchanger coils absorb the heat
generated by the burners and transfer heat to the water.
When the hot water faucet is shut off, the gas valve
automatically closes and the burners turn off, followed
immediately by the exhaust system. Your hot water faucet is
an ignition key to turn on the water heater, giving you control
over your hot water energy use. Every time you turn off your
hot water faucet, the energy consumption for hot water
returns to zero.
FEATURES
- Electronic Pilot Ignition
- On/Off switch to activate system
- Power Venting with safety shutoff
- High Quality Materials for Long Working Life.
- Copper heating coils for endless supply of hot water.
- Burner output proportional to hot water flow demand for
maximum energy efficiency.
- Safety flame sensor at pilot burner.
- Automatic overheating protection shut-off sensor.
- Stainless steel burners with stabilized blue flame.
- Built-in corrosion resistant power venter.
- Compact space saver: mounts on a wall with two hooks.
- Easily removable one-piece cover.
- Easy one person installation.
- Adjustable water flow restrictor to ensure that water flow
demand will not exceed the heating capacity of the heater.
UNPACKING THE 425 EF HEATER
This heater is packed securely. The box includes one water connection fitting, a control knob with collar, a gas pressure
regulator, a pressure relief valve, an incandescent particle tray, two hooks for hanging the heater, this manual and a
warranty registration card. Do not lose this manual as there is a charge for replacement. Please complete and return
the enclosed warranty registration card. The FXHOOD horizontal vent terminator is supplied separately from the 425EF
water heaters. There is a set of installation instructions in the FXHOOD box.
425EF NG 425 EF LP
max. 130 000 Btu/hr 125 000 Btu/hr
min. 28 000 Btu/hr 28 000 Btu/hr
Gas input