GWH 425 HNO OUTDOOR MODEL For exterior use only Electronic Ignition Suitable for heating potable water only - Not approved for space heating purposes GWH-425-HNO-N - Natural Gas GWH-425-HNO-L - Liquefied Petroleum (LP) Gas Warning: If the information in this manual is not followed exactly, a fire or explosion may result causing property damage, personal injury or death. Do not store or use gasoline or other flammable vapor and liquids in the vicinity of this or any other appliance. 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. In the Commonwealth of Massachusetts this product is approved only for seasonal use. Installation must be performed by a licensed plumber or gas fitter. Upon completion of the installation, these instructions should be handed to the user of the appliance for future reference. What to do if you smell gas · Close gas valve. · Do not try to light any appliance. · Do not touch any electrical switch; do not use any phone in your building. · If you cannot reach your gas supplier, call the fire department. · Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's instructions. 8 716 473 148 US (05.12) AL · Installation and service must be performed by a qualified installer, service agency or the gas supplier. Index Index 1 2 2.1 2.2 2.3 2.4 2.5 3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 4 4.1 4.2 4.3 4.4 4.5 5 5.1 5.2 5.3 5.4 5.5 5.6 6 6.1 6.2 6.3 6.4 6.5 6.6 7 7.1 7.2 7.3 8 9 Warning Appliance details Features GWH-425-HNO specifications (Technical data) Unpacking the GWH-425-HNO heater General rules to follow for safe operation Dimensions and installation clearances Installation instructions Introduction Proper location for installing your heater Heater placement and clearances Mounting installation Gas piping & connections Measuring gas pressure Water connections Electrical connections Operation instructions For your safety read before operating your water heater Lighting instructions To turn off appliance Setting the water temperature Electrical diagram Maintenance and service Maintenance intervals Water valve Pilot Main burners Vent assembly Mineral scale build-up Troubleshooting Introduction Pilot will not light Pilot lights but the burners will not come on Hot water temp fluctuates from hot to cold Water is too hot Water is not hot enough Interior components diagram and parts list Interior components Components diagram Parts list Protecting the environment Fifteen Year Limited Warranty 2 4 4 4 5 5 6 7 7 7 8 8 10 12 12 13 14 14 14 14 14 16 17 17 17 17 17 17 17 18 18 18 18 18 19 19 20 20 21 22 23 24 1 Warning Warning: If the information in this manual is not followed exactly, a fire or explosion may result causing property damage, personal injury or death. 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. For your safety Do not store or use gasoline or other flammable, combustible or corrosive vapors and liquids in the vicinity of this or any other appliance. Warning: Carefully plan where you install the heater. If a gas appliance is not installed correctly, fatal accidents can result from lack of air, carbon monoxide poisoning or fire. Warning: Place the heater in a location where water leaks will do NO DAMAGE to adjacent areas. 2 8 716 473 148 Warning What to do if you smell gas · Close gas valve. · Do not try to light any appliance. · Do not touch any electrical switch; do not use any phone in your building. · Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's instructions. · If you cannot reach your gas supplier, call the fire department. · Installation and service must be performed by a qualified installer, service agency or the gas supplier. Warning: The heater must be isolated from the gas supply piping system during any pressure testing of that system at test pressures equal to or more than 0.5 psig. Caution: Any changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment. Fig. 2 Fig. 1 8 716 473 148 3 Appliance details 2 2.1 Appliance details Features · Water valve material: Polymer (PPS) (Polypropylene Sulfid) · Minimum water flow: 0.5 gallon/minute (1.9 l/m) · Minimum recommended water pressure: 30 PSI (2.07 bar) · Connections: ­ Bottom of heater Dimensions · Depth (in): 10.5" (265 mm) · Width (in): 18.25" (460 mm) · Height (in): 36.75" (936 mm) · Weight: 64 pounds (29 kg). Gas types Natural Gas. LP Gas Safety devices · Flame failure device (ionization flame rod sensor) · Pressure relief valve (supplied with heater) · Over heat prevention (temperature limiter). Water resistant IP X5 (protection against water drops). · Burner output proportional to hot water flow demand for maximum energy efficiency · Stainless steel burners with stabilized blue flame · Built-in corrosion resistant draft diverter · Adjustable water flow restrictor to ensure that water flow demand will not exceed the heating capacity of the heater · Safety flame sensor at pilot burner · Automatic overheating protection shut-off sensor · Copper heating coils for endless supply of hot water · Easily removable one-piece cover · Easy one person installation · Electronic Pilot Ignition driven by hydro-generator. BOSCH is constantly improving its products, therefore specifications are subject to change without prior notice. i 2.2 GWH-425-HNO specifications (Technical data) Approved in US/Canada Capacity Maximum flow rate: 3.7 GPM (14 l/min) at a 45°F (25°C) rise. Maximum output 101,772 Btu/h (29.8 kW) Maximum input 117,000 Btu/h (34.3 kW) Efficiency in % Recovery efficiency 80% Min. Output 28,000 Btu/h (8.2 kW) Gas Requirement Gas connection (inches) - ¾" Inlet gas pressure under maximum operation* · Propane: 10.5" - 14" water column · Natural Gas: 5.7" - 14" water column. * To measure Gas Pressure, see Measuring Gas Pressure, chapter 3.6. Water · Hot water connection (inches) - ½" · Cold water connection (inches) - ½" 4 8 716 473 148 Appliance details 2.3 Unpacking the GWH-425-HNO heater 2.4 General rules to follow for safe operation This heater is packed securely. Before installing the unit, be certain you have the correct heater for your type of Gas - Propane or Natural Gas. Identification labels are found on the shipping box, and on the rating plate which is located on the right side panel of the cover. The box includes: · Pressure relief valve · Heat shield · Mounting screws · Product registration card · Installation manual. Do not lose this manual, there is a charge for a replacement. Please complete and return the enclosed product registration card. The GWH-425-HNO is not approved or designed for: · Manufactured (mobile) homes, RV's or boats · Heating or other recirculating/pumping applications* · Solar/preheat backup or high temperature booster use * This includes domestic hot water circulator pump loop systems that may previously exist in a home hot water system. The use of a small electric mini-tank (4-6 gallon size) should be used for this application; when designed so the pump will circulate the hot water in the mini-tank only and through the building's hot water return loop (timed or thermostatic controlled operation of the pump is commonly done). The GWH-425-HNO should be plumbed in line before the mini-tank water heater, contact BBTNA if further instruction is needed. B 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. B 2. Carefully plan where you install the heater. Proper clearances must be followed. B 3. The appliance must be isolated from the gas supply piping system by closing its individual manual gas shutoff valve (not supplied with heater) during any pressure testing at pressures in excess of ½ Psig (3.5 kPa). The appliance and its gas connection must be leak tested before placing the appliance in operation. B 4. Keep water heater area clear and free from combustibles and flammable liquids. Do not locate the heater over any material which might burn. B 5. Correct gas pressure is critical for the optimum operation of this heater. Gas piping must be sized to provide the required pressure at the maximum output of the heater, while all the other gas appliances are in operation. Check with your local gas supplier, and see the section on connecting the gas supply. B 6. Should overheating occur or the gas supply fail to shut off, turn off the gas supply at the manual gas shut off valve, on the gas line. Note: manual gas shutoff valve is not supplied with the heater. B 7. Do not use this appliance if any part has been underwater. Immediately call a qualified service technician to inspect the appliance and to replace any part of the control system and any gas control which has been underwater. 8 716 473 148 5 Appliance details 2.5 Dimensions and installation clearances Fig. 3 Dimensions Model GWH-425-HNO TOP (A) FRONT (B) BACK SIDES BOTTOM (C) 3 ft. 4 ft. 0" 4 ft. 1 ft. Table 1 Minimum clearances Fig. 4 Minimum clearances 6 8 716 473 148 Installation instructions 3 3.1 Installation instructions Introduction Danger: Flue gases will be released through the vent cap. Flue gas is very hot and contains carbon monoxide. The heater cannot be installed indoors. To prevent risk of fire and poisoning by carbon monoxide, assure all clearances indicated in manual. Danger: Surface temperature around vent cap is less than 140°F, except highest top surface of vent cap may reach 300°F. Danger: Do not place or store any combustible material within 5 feet of the appliance. Risk of fire could be caused by hot flue gas. Warning: Flammable materials, gasoline, pressurized containers, or any other items or articles that are potential fire hazards must NOT be placed on or adjacent to the heater. The appliance area must be kept free of all combustible materials, gasoline and other flammable vapors and liquids. Please follow these instructions. Failure to follow instructions may result in: B Damage or injury. B Improper operation. B Loss of warranty. Please contact BBT North America with any questions. 3.2 Proper location for installing your heater Carefully select the location of the water heater. Follow the guidelines below: B 1. Locate the heater where an adequate gas line size and plumbing connections are feasible and convenient. B 2. The hot water lines should be kept short to save energy. Centrally locating the water heater is best. It is always best to have hot water lines insulated to prevent the possibility of any freeze damage. B 3. The water in this heater is cold and always remains cold except for the times that hot water is being used. The heater is equipped with freeze prevention equipment that will operate and prevent freezing of the water in the heater to 5°F with no wind chill. Electrical power must be maintained to the heater to allow this to function. WARNING: Proper insulation of the water lines below the heater is required if below freezing temperatures, below 32°F, are ever anticipated! Danger: If the temperature drops below 32°F, freeze damage to the water heater itself must be prevented by turning off the power to the heater, then disconnecting the plumbing connections, as well as removing the drain plug and introducing short bursts of compressed air (20-40 psi) through the heater's connections. This will remove the residual water in the horizontal pipes and water valve. Danger: Keep children away as the top of the water heater vent cap will get very hot during operation. Install in a place that prevents the top of the heater being reached by small children. 8 716 473 148 7 Installation instructions 3.3 Heater placement and clearances 3.4 Mounting installation Warning: before starting installation: B check that there are no loose parts inside the appliance B ensure that gas pipe, gas valve, and burner have no damage and are properly fitted. The GWH-425-HNO is design certified for installation directly on a combustible wall. (see 3.4 Mounting installation) For installation on vinyl siding see Fig. 7. Keep the area below the heater free of combustible material. Minimum clearances If the appliance is installed under ...