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Instantaneous gas water heater
POWER VENTED - ELECTRONIC IGNITION
Model
WR430-7K
• installation
• operation
• maintenance
The Bosch instantaneous water heater is a high efficiency,
space saving answer to your water heating needs. All Bosch
instantaneous water heaters heat water only as required;
no energy is lost maintaining a large volume of water at
elevated temperatures as in tank-type storage water heaters.
Suitable for heating potable water only. Not approved for
space heating purposes.
REA
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BOSCH WR430-7K NAT. GAS PROPANE max. 130 000 Btu/hr 125 000 Btu/hr Principle of Operation: Gas Input min. 28 000 Btu/hr 28 000 Btu/hr 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. Water Connection 1/2” Thread fitting The flame sensor confirms that the pilot has been lighted and allows burners to ignite. The pilot goes out. The power H x W x D 29 3/4” x 18 1/4” x 8
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DIMENSIONS EXTERIOR TERMINATION Figure 1 Maximum Hydrostatic water pressure - 1.03 MPa (150 p.s.i.) Maximum recommended working pressure - 0.69 MPa (100 p.s.i.) Minimum working pressure - 0.09 MPa (13 p.s.i.) no piping attached Reccomended pressure for showers and domestic, 0.27 MPa (40 p.s.i.) Main Burner Orifices Model Type of Gas Altitude Input Size, mm Qt. natural gas 130 000 Btu/hr (38 kW) 1.20 diam. 18 standard (0 - 2 000 ft) propane/LP 125 000 Btu/hr (36.6 kW) 0.79 diam. 18 WR430-7.K.. na
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FORWARD The design of the WR430-7K complies with CAN 1-4.3 The BOSCH instantaneous gas water heater is designed and ANSI Z21.10 (latest edition) as an instantaneous gas to operate on natural or propane gas: however, make sure water heater. In addition, the WR430-7K also complies with that gas on which heater is to operate is the same as CAN 1-2.17 for use at high altitudes, 2,000 - 4,500 ft. above specified on the heater’s model/rating plate. sea level. In addition to these instructions, the wat
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For either a confined or unconfined space in a building of MOUNTING tight construction with inadequate infiltration, air must be drawn from the outdoors or from spaces that freely The WR430-7K is design certified for mounting to a wall. communicate with the outdoors. Two permanent openings The heater must not be installed on a carpeted wall. The located as indicated are to be provided as follows: heater must be mounted to the wall using appropriate anchoring materials. 1. When communicating with
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Bosch POWER VENTING SYSTEM INTRODUCTION Bosch power venting models are designed to overcome difficult venting problems which cannot be performed with atmospheric venting: to meet your hot water demand load very efficiently, with an environmentally friendly appliance which conserves energy and significantly reduces combustion emissions to atmosphere. GENERAL INFORMATION This Power Vent System must be installed by a *qualified installer in accordance with all applicable local gas and electrical c
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Bosch POWER VENTING SYSTEM GENERAL VENTING INFORMATION - continued APPROVED VENTING MATERIALS: Single wall: As gauge listed in the current CAN1/CGA B149 installation code for gas burning appliances (for Canada), National Fuel Code ANSI Z223.1-LATEST (for USA). Note: Cannot be used in concealed locations. B-Vent materials: Straight lengths only (no elbow) may be used under following conditions (i) Unsealed 5” B-vent may be used as a chase for sealed 4” single wall through concealed or unheated ar
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Bosch POWER VENTING SYSTEM VENT TERMINAL INSTALLATION: Before installing Bosch WR430-7K determine the location of vent system termination which may be immediately connected with a 90° elbow or with a maximum lineal length of 15 feet including two 90° elbows. (See Fig. 1) 90° el 12 ft straight (5.7m) 90° el 90° el 15 ft straight 3 ft straight (4.6m) (0.3m) 90° el MAXIMUM LENGTH OF ALL PIPE LENGTHS MUST NOT EXCEED 15 FT (4.6M) Note: In cold climate areas negative air pressure such as unbalanced he
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72” Bosch POWER VENTING SYSTEM Figure 2 36” 36” REGULATOR VENT ELECTRICAL WIRING: 1. The electrical contact ratings are as follows: ______ 1/10 HP at 120 VAC ______ 3 Amps (full load) at 120 VA 2. Provide switched plug receptacle to accommodate Bosch grounded plug. 3. Make certain the power source is adequate for the fan motor requirements. VENT INSTALLATION 1. Choose approved terminal location 2. Cut vent terminal opening through outside wall - Refer to installation instructions supplied with
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Bosch POWER VENTING SYSTEM VENT INSTALLATION (continued) 6. Support venting duct with plumber’s strap (supplied by installer). Solid piping need only be supported every four feet. All horizontal pipe joints must be secured with a minimum of four screws per joint. (See Figure 3) 7. All runs through unheated spaces must be wrapped and insulated with a minimum of 1” insulation. Figure 3 Vent support hangers (plumber's strapping) should be 4 ft. apart on horizontal runs. Use 4 screws per joint RIGI
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Bosch POWER VENTING SYSTEM B. The Air-Flow Adjustment on the Power Venter is factory set for optimum air flow. Operating at its setting will assure that combustion gases are safely removed to the outside. MAINTENANCE Points of inspection are: 1. Motor - Motor must rotate freely. 2. Fan Wheel - Wheel must be clean of dust or any other coating which inhibits rotation or air flow. Remove all foreign material from vent system before operation. 3. Spill Switch - Verify proper spill switch operation b
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DRIP TRAY WATER CONNECTIONS If the water heater is being mounted above a floor of The BOSCH instantaneous water heaters are provided with combustible construction the drip tray (shipped loose in the two S-bend water connectors/adaptors that must be carton with the water heater) must be attached to the bottom connected to inlet and outlet connections on water valve of the front cover of the water heater at the time of assembly, see Figure 4, below. installation. The drip tray should be attached t
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RELIEF VALVE Check to make sure that the gas listed on the rating plate is The listed pressure relief valve supplied must be installed same as gas listed on the pressure regulator. See near the hot water outlet at time of installation of the heater. PRESSURE REGULATION section of this manual for No valve is to be placed between the relief valve and the information regarding gas pressure settings. heater. A drain line must be connected to the relief valve to direct discharge to a safe location. D
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OPERATING INSTRUCTIONS WARNING! LIGHTING AND OPERATING INSTRUCTIONS 1. STOP! Read the safety information above on this lable. 2. The gas valve must be shut off by putting the ON/OFF If the water heater has been damaged or exposed to fire or switch to position “ ” Wait five (5) minutes to clear out sooting, or if any part has been underwater, do not use. If any gas. If you smell gas, STOP! Follow “B” in the safety unit has been operated during construction or alterations information above. If you
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PRESSURE REGULATION Your appliance dealer and/or your local gas supplier should be consulted in regard to any high altitude installation. If The pressure regulator supplied with the water heater is field adjustment is required it should be performed by a adjusted to operate on the gas specified on the rating plate qualified serviceman experienced in such work. and: • in Canada, is factory preset to deliver gas at the high TEMPERATURE REGULATION altitude setting listed on the rating plate and as
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Do not enlarge the orifice. MAINTENANCE AND SERVICE Do not use any wire or sharp object to clean orifices. Natural Approximately once a year, the Bosch should be checked, cleaned and serviced as necessary. To remove the front cover, gas orifices are large enough that you can usually clean first remove the incandescent particle tray, then pull off the them by blowing through them. To access the pilot orifice, temperature adjustment knob and unscrew and remove the remove 2 screws holding pilot ass
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4. Cross over in water lines Maintenance* To confirm there is no cross-over in the plumbing, shut off the cold water supply to the Bosch water heater and open a If faults occur on the flue gas safety device, proceed as hot water faucet. There should not be any water flowing at follows: that faucet. Water running is a sign of a plumbing cross - Undo flue gas safety device fixing screw. over. Consult your plumber. - Unplug igniter unit connector. Replace damaged component with new one and refit us
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7. Cold incoming water connection made to wrong side PILOT SPARKS CONTINUOUSLY WITH of heater Make sure cold water inlet connection is on the right side of NO WATER RUNNING heater when you are facing heater. 1. Microswitch needs adjustment 8. Water valve parts may be dirty of components damaged If no water is running, but pilot electrode continuously sparks, First check that venturi is free of dirt particles. Water valve the microswitch screw to the water valve needs adjustment. and component pa
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6. Check Blower Fan. Is it operating when burner comes HOT WATER TEMPERATURE on? FLUCTUATES 7. Check flapper in outside vent termination for free movement. 1. Unbalanced pressure in waterlines. The added restriction caused by the Bosch in the hot water WATER IS TOO HOT system can result in uneven pressures between the cold and the hot. In such cases when mixing cold water at the 1. Check for lime build-up. (See mineral scale p. 16) tap, the lower hot water pressure may be overpowered by a 2. Tem
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Fig. 15 - Diagram of WR430-7K 13 See fig 7, page 13 1 3 2 4 5 6 9 7 10 See table 1 on 8 page 15 11 12 1. Heat exchanger 8. Power cord 2. Pilot assembly 9. on/off switch 3. Burner manifold gas 10. Temperature adjustment pressure test nipple selector 4. Main gas burner 11. Microswitch 5. Pilot gas tubing 12. Gas inlet gas pressure test 6. Gas valve nipple 13. Exhaust Fan 7. Electronic control box 20 6 720 606 599
