TABLE OF CONTENTS WARNING : Improper installation, adjustment, alteration, service or maintenance can cause injury or property damage. Refer to this manual. For assistance or additional information consult a qualified installer, service agency or the gas supplier. Upon completion of the installation, these instructions should be handed to the user of the appliance for future reference. In the Commonwealth of Massachusetts this product must be installed by a licensed plumber or gas fitter.
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.
FRONT VIEW SIDE VIEW MINIMUM INSTALLATION CLEARANCES FROM COMBUSTIBLE AND NON COMBUSTIBLE MATERIALS FOR ALCOVE OR CLOSET INSTALLATIONS * 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.
GENERAL RULES TO FOLLOW FOR SAFE OPERATION 1. You should follow these instructions when you install your heater. 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.(1,2) INSTALLATION CODES and /or local installation codes. 2. Carefully plan where you install the heater. Correct combustion air supply and flue pipe installation are very important.
COMBUSTION AIR REQUIREMENTS The 425 EF water heater holds cold water in its copper heat exchanger and brass water valve when not in use. Because of this, any cold air that comes in through the unit’s vent pipe is capable of freezing these components. This Installation Manual specifies the vent length requirements and the amount of combustion air required for this unit. When all requirements are followed, the unit will operate properly and safely.
MOUNTING INSTALLATION The 425 EF is design certified for mounting on a wall. 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 combustible, such as carpet. The heater must be mounted on a wall using appropriate anchoring materials.
VENTING WARNING: Do not reduce the vent pipe size and do not common vent with any other vented appliance or stove. This appliance must be vented horizontally to the outside with a sealed 4” single wall vent pipe. The appliance’s flue gasses are under positive pressure and must travel through a single wall 4” pipe that is sealed gas tight. The 4” single wall vent pipe can be either stainless steel (AL29-4C) or galvanized steel with at least 26 gauge.
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.
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 regulator.
GAS LINE SIZING GAS CONNECTIONS NOTE: The 425 EF is supplied with a gas pressure regulator that must be installed on the heater before attaching the gas supply line. See figure 6. Failure to install the gas regulator as shown in figure 6 will be a violation of CSA certification of the unit. The regulator supplied with the heater is preset for the gas shown on the rating plate to the correct pressure. It is an appliance level regulator designed for (low inlet) pressure (less than 1/2 Psig or 15” W.C.
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.
Connecting the pressure relief valve (PRV) WATER CONNECTIONS Install the heater centrally in the building if possible and make hot water piping runs as short as possible When facing the heater, the cold water inlet will be on the right and the hot water outlet on the left.. Although water piping throughout the building may be other than copper, copper or galvanized piping should be used when connecting to the heaters ½” male NPT flex connectors (follow local codes if more stringent).
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.
OPERATING INSTRUCTIONS Before operating the heater, make sure that the system is filled with water. Open the cold water inlet supply to the heater fully. Open a hot water faucet to permit the water to fill the heater and the piping and to eliminate the air trapped in the system Close the hot water faucet after the water flows freely and all the air has escaped from the system. The water heater is now ready to operate.
140° and 95°F at various flow rates between 2.0 and 4.0 gallons per minute. The position you select on the temperature selector dial will depend on the temperature of the incoming water (50°F is average in the U.S.). In warm weather regions where the incoming cold water is generally warmer, or during the hot weather months in some other areas a midway setting on the temperature selector knob will produce a temperature rise of about 70°F, giving an output of approximately 120°F.
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.
Mineral deposits can eventually (3-5 years in hard water areas) corrode the water valve parts to a point where they will need replacing. Any sign of moisture at the bleed hole is a sign that the water valve needs to be replaced immediately. 10. Poor circuit connections at the ECO (overheat sensor) or the flue gas safety device Ignition sparker will not operate if the electrical circuit is interrupted. Check that the connections to the ECO are secure and tighten if necessary. 11.
WATER IS TOO HOT 1. Temperature Selection too high Turn the temperature adjustment knob counter-clockwise (to the left) to lower the maximum water temperature. Note: This will increase the activation flow rate. 2. Inlet water temperature is very warm (60°-75°F) Reduce inlet gas supply to lower the heaters degree rise. Note: Only the Model 125BS should be used if the inlet water is preheated. NOTE: Only the model 125B LPS or 125B NGS should be used if the inlet water is preheated. 3.
Fig. 15 - Diagram of 425 EF 13 1 3 2 4 5 6 9 10 7 8 11 14 12 6 720 606 601-12.1AL 1. 2. 3. 4. 5. 6. 20 Heat exchanger Pilot assembly Burner manifold gas pressure test nipple Main gas burner Pilot gas tubing Gas valve 7. 8. 9. 10. 11. 12. 13. 14.
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Fifteen Year Limited Warranty General B OSCH PR O water heaters are warranted by the Manufacturer (BOSCH) through Controlled Energy Corp. Controlled Energy Corp. (CEC) will furnish a replacement heat exchanger and will furnish a replacement of any other part which fails in normal use and service within the applicable periods specified below, in accordance with the terms of this warranty. The CEC replacement will be warranted for the unexpired portion of the original warranty.
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MAIN TEN AN C E TAB LE see page 16 EVERY YEAR EVERY 2 YEAR S EVERY 3-5 YEAR S † LU B R IC ATE WATER VALVE † R EB U ILD WATER VALVE IN SPEC T WATER FILTER SC R EEN † IN SPEC T PILOT ASSEMB LY † IN SPEC T VEN T ASSEMB LY † IN SPEC T MAIN B U R N ER † Replacement Parts available from North American Distributor CONTROLLED ENERGY CORP. 340 Mad River Park Waitsfield, Vermont 05673 Phone 866-330-2730 Fax (802) 496-6924 www.protankless.com techsupport@protankless.