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Water heaters for use with Natural and L.P.G.
GWH 425 EF
Flow Modulated with Electronic Ignition and Power Venting
Suitable for heating potable water only - Not approved for space heating purposes
(Intended for variable flow applications with steady cold water inlet temperatures)
GWH-425-EF-N
GWH-425-EF-L
Warning: If the information in this manual is not What to do if you smell gas
followed exactly, a fire or explosion may result
• Close gas valve. Open windows.
causing property damage, personal
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TABLE OF CONTENTS WARNING: Improper installation, Specifications ............................................................... Page 3 adjustment, alteration, service or maintenance can cause Rules for safe operation ............................................. Page 5 injury or property damage. Refer to this manual. For Locating the Heater .................................................... Page 5 assistance or additional information consult a qualified Combustion Air Requirements ...........
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Principle of Operation: 425 EF LP and 425 EF NG Specifications When a hot water faucet is opened, the flow of water through 425EF NG 425 EF LP the heater causes the gas valve to open. At the same time a microswitch is activated which sends a spark to the pilot. max. 130 000 Btu/hr 125 000 Btu/hr Gas input The flame sensor confirms that the pilot has been lighted min. 28 000 Btu/hr 28 000 Btu/hr and allows the first two burners to ignite. The flame sensor confirms correct activation and all burne
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FRONT VIEW SIDE VIEW MINIMUM INSTALLATION CLEARANCES FROM COMBUSTIBLE AND NON COMBUSTIBLE MATERIALS FOR ALCOVE OR CLOSET INSTALLATIONS MODEL 425 EF TOP (A) 12 " FRONT (B) 4 " BACK 0 " * SIDES 4 " FLOOR (C) 12 " VENT DIAMETER 4 " * On a combustible wall surface the unit should be mounted away from the wall to provide adequate clearance of the vent pipe. See page 5 for instructions. MODEL 425 EF 4 6 720 607 017
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The heater may still operate even when improperly vented. GENERAL RULES TO FOLLOW It will, however, be less efficient and could eventually damage FOR SAFE OPERATION the heater. It could even result in human sickness or death due to oxygen deprivation and carbon monoxide poisoning. 1. You should follow these instructions when you install your Before installing the unit, be certain you have the correct heater. In the United States: The installation must conform heater for your type of Gas – Propan
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Appliances located in confined spaces: The confined space COMBUSTION AIR REQUIREMENTS must be provided with two permanent openings, one The 425 EF water heater holds cold water in its copper commencing within 12 inches of the top and one heat exchanger and brass water valve when not in use. commencing within 12 inches of the bottom of the enclosure. Because of this, any cold air that comes in through the Each opening must have a minimum free area of one square unit’s vent pipe is capable of free
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The incandescent particle tray (shipped loose in the carton MOUNTING INSTALLATION with the water heater) must be attached at the bottom of the water heater front cover at the time of installation. Use The 425 EF is design certified for mounting on a wall. the screws provided. See figure 3. Secure the two L shaped hooks, which are provided with heater, to a wall surface. Place them 13 ¼” apart as shown in Fig 2. Do not install this appliance on a carpeted wall or over floor covering which is com
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feet (4.6 m) with two 90-degree elbows. Subtract 5 feet from the total vent length for each additional 90-degree VENTING elbow used. No more than four 90-degree elbows may be used. Any short vertical portion of vent pipe used in the vent system shall be considered part of the allowable 15 WARNING: Do not reduce the vent pipe size and feet (4.6 m) maximum run. Support the vent run at 4 foot do not common vent with any other vented appliance or intervals with overhead hangers. Horizontal sections
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4”single wall venting only. Use stainless steel (AL29-4C) or galvanized pipe of 26 minimum gauge must be used. Each connection must be properly sealed. Approved Vent Terminal (FXHOOD or other approved terminal) The FXHOOD is design approved with the 425 EF and has a built in back draft flapper to prevent negative air from freezing the 425 EF – see Fig. 5 for restrictions in location of vent terminal. HORIZONTAL SIDE WALL * Maximum 15 feet with 2 elbows. Deduct 5 feet for each additional elbow.
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SOFFIT 7’ MINIMUM ABOVE PUBLIC WALKWAY The approved vent terminal must be installed so that flue gases will not jeopardize people, overheat combustible structures or enter into buildings, and so that proper clearances are maintained (See Fig 5). a) The vent terminal shall not be less than 7 feet above a public walkway. b) The vent terminal shall terminate at least 3 feet above any (mechanical) air inlet within 10 feet. c) The vent terminal shall not be within a 6-foot radius from a gas meter or
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GAS LINE SIZING -It is strongly recommended that the Natural Gas pipe GAS CONNECTIONS be Black Iron pipe the entire distance from the outside meter to the inlet of the 425 EF regulator. 1/2” Black Iron pipe up to 10 feet, 3/4” Black Iron pipe up to 40 feet and 1” Black Iron pipe up to 125 feet distances. Flex line tubing NOTE: The 425 EF is supplied with a gas pressure is NOT recommended, but if used then oversize it. regulator that must be installed on the heater before -It is strongly recommen
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GAS PIPING, CONNECTIONS Before connecting the gas supply, check the rating plate on the right side of the front cover to be sure that the heater is rated for the same gas to which it will be connected. In the United States: The installation must conform with local codes or, in the absence of local codes, the National Fuel Gas Code ANSI Z223.1/NFPA 54. In Canada: The Installation should conform with CGA B149 INSTALLATION CODES and /or local installation codes. GAS LINE SIZING FOR NATURAL GAS Foll
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Connecting the pressure relief valve (PRV) WATER CONNECTIONS The listed pressure relief valve supplied with the heater must be installed at the time of installation. Should a discharge line be added to the PRV no valve is to be placed between the PRV and the heater. No reducing coupling or other Install the heater centrally in the building if possible and restriction may be installed in the discharge line. The make hot water piping runs as short as possible When facing discharge line must be ins
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ELECTRICAL CONNECTIONS WARNING: For safety reasons, disconnect the power supply to the heater before any service or testing is performed. WARNING: This heater must be electrically grounded in accordance with the most recent edition of the National Electrical Code, NFPA 70. In Canada, all electrical wiring to the heater should be in accordance with local codes and the Canadian Electrical Code, CSA C22.1 Part 1. Do not rely on the gas or water piping to ground the metal parts of the heater.
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OPERATING INSTRUCTIONS 6. Turn the hot water faucet on to the minimum flow required to activate the heater. The automatic ignition system first Before operating the heater, make sure that the system is ignites the safety pilot burner which then ignites the main filled with water. burner in about 4 seconds. The power exhaust will then activate. Open the cold water inlet supply to the heater fully. 7. The pilot flame will extinguish 10-30 seconds after the Open a hot water faucet to permit the wat
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140° and 95°F at various flow rates between 2.0 and 4.0 Water Valve (Part # 8707002802): The water valve on gallons per minute. The position you select on the this heater should be serviced periodically. Lubricate temperature selector dial will depend on the temperature of component #36 on page 22 with a small amount of silicon, the incoming water (50°F is average in the U.S.). In warm faucet or lithium grease every two years to keep its o rings weather regions where the incoming cold water is
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3. Water flow is not sufficient to activate heater. Water flow rate at faucet is below minimum flow needed to activate heater. When temperature adjustment knob is turned all the way clockwise, the model 425 EF requires 1/2 gallon per minute flow to activate the heater. As a reference, this is a flow which would fill a quart jar in 30 seconds. If the temperature adjustment knob is turned fully counterclockwise, a flow rate of 1.1 gallons/minute is required to activate the heater. 4. Bad fuse Chec
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PILOT SPARKS CONTINUOUSLY WITH NO WATER Mineral deposits can eventually (3-5 years in hard water RUNNING areas) corrode the water valve parts to a point where they will need replacing. Any sign of moisture at the bleed hole 1. Microswitch needs adjustment is a sign that the water valve needs to be replaced If no water is running, but pilot electrode continuously sparks, immediately. the microswitch screw to the water valve needs adjustment. See Figure 14. 10. Poor circuit connections at the ECO
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WATER IS TOO HOT HOT WATER TEMPERATURE FLUCTUATES / UNIT DEACTIVATED 1. Temperature Selection too high 1. Unbalanced pressure in waterlines Turn the temperature adjustment knob counter-clockwise The added restriction caused by the 425 EF in the hot water (to the left) to lower the maximum water temperature. system can result in uneven pressures between the cold Note: This will increase the activation flow rate. and the hot. In such cases when mixing cold water at the tap, the lower hot water pre
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20 6 720 607 017
