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COMMERCIAL / RESIDENTIAL GAS WATER HEATERS
SERVICE HANDBOOK
UL TRA HIGH EFFICIENCY
POWER VENT / POWER DIRECT VENT
FOR MODELS:
• SHE50-100 NE
• SHE50-100 PE
• GP650 YTPDT
• GP650 HTPDT
PRINTED 0308 198148-000
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT SERVICE MANUAL Technical Literature Department ©2008 TABLE OF CONTENTS INTRODUCTION ............................................................ 2 TROUBLESHOOTING...................................................41 Qualifications ............................................................ 2 Rough Start - Rough Operation ............13 and 41 Service Warning ....................................................... 2 Heater Status Menu..........
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL INTRODUCTION This Service Manual is designed to be an aid in servicing and troubleshooting the 96% thermally efficient, 50 gallon, 100,000 Btu/hr residential and light duty commercial power vent - power direct vent model water heaters listed on the cover of this manual.The instructions, illustrations and procedures contained in this manual are used to verify proper operation and to diagnose and repair common service problems
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL INSTRUCTION MANUAL Have a copy of the Instruction Manual that came with the water heater on hand for the correct model water heater you are working with before servicing. Installation information given in this Service Manual is not a complete installation instruction. Installation information covered in this Service Manual has a limited focus as it applies to servicing. This Service Manual does not replace or supersede the In
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL INSTALLATION CONSIDERATIONS INSTRUCTION MANUAL Installation information given in this Service Manual is not a complete installation instruction. Installation information covered in this Service Manual has a limited focus as it applies to servicing. This Service Manual does not replace or supersede the Instruction Manual that came with the water heater. Always refer to the Instruction Manual that came with the water heater fo
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL AIR REQUIREMENTS Carefully review the requirements for combustion and ventilation air in the Instruction Manual that came with the water heater. Failure to meet these requirements when the water heater is installed or overlooking their importance when servicing the water heater often results in needless down time, unnecessary parts replacement, and customer dissatisfaction. If the Instruction Manual is not on hand copies can
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL VENTING The venting information presented in this Service Manual is not a complete venting installation instruction. Refer to the Instruction Manual that came with the water heater for complete installation instructions. The water heater covered in this Service Manual may be installed as a conventionally vented water heater or as a direct vent water heater. Conventional vent installations use room air for combustion. There w
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL VENTING (CONT) Pipe Size Requirements Ensure the correct size pipe has been used for the overall equivalent length of the vent and intake air piping installed. Longer equivalent lengths require larger pipe sizes, see Table 1. Maximum Elbow Requirements Three and four inch vent and intake air pipe installations allow a maximum of 6 - 90° elbows in the vent pipe AND a maximum 6 - 90°elbows in the intake air pipe. Two inch instal
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL ELECTRICAL REQUIREMENTS The water heater covered by this Service Manual must be grounded in accordance with the local codes, or in the absence of local codes: the National Electrical Code (NFPA 70) or the Canadian Electrical Code (C22.1). The water heater covered by this Service Manual requires a 120 VAC 1Ø (single phase) power supply. It is factory equipped with a standard 3 prong appliance cord that plugs into a standard 1
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL OPERATION & SERVICE HOW IT WORKS This section of the Service Manual will cover operation, common service procedures and water heater construction. The water heater covered in this Service Manual has a helical coil shaped heat exchanger that is submerged in the storage tank. The water heater uses a top mounted down fired radial burner. This is a forced draft burner; hot burning gases are forced through the heat exchanger unde
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL BLOWER The blower is an assembly consisting of the blower housing, motor and an integrated VFD (variable frequency drive). Blower operation is controlled by the CCB (central control board - page 35). The CCB sends 120 VAC to the Blower/VFD assembly high voltage 3 pin socket. The CCB also sends a PWM (pulse width modulation) signal to the Blower/VFD assembly low voltage 5 pin socket. The PWM signal is a digital instruction se
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL BURNER The images below show a complete blower/burner assembly removed along with a top view of the water heater with the blower removed. Service Notes - Burner (Flame Sensor) The burner installed in the water heater is a radial fire burner. Radial fire burners can trap debris that enter the blower. Be sure to thoroughly clean the edges of intake air pipe sections after cutting during the installation. If this is not done pla
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL BURNER (CONT) Burner & Blower Removal The burner should be removed and inspected whenever service is being performed for rough operation or ignition failure. Radial fire burners like the one used on this water heater can trap debris, see Service Notes - Venting on page 7. The following images illustrate the burner removal procedure. Long T handle hex wrenches (8-10”) will save considerable time when removing/installing the b
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL BURNER (CONT) Burner/Blower Removal (cont) BLOWER/BURNER REMOVAL PROCEDURE (CONT) 9 Remove 4 blower adapter 1/4” hex machine screws. Do not over tighten when reinstalling - torque should not exceed 40 inch lbs. 1/4” Hex Machine Screws 10 Remove the blower adapter. 11 Be extremely careful when handling the Sight Glass inside the Burner View Port (page 11) this can easily be dropped and lost - and the water heater must have
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL VENTURI A Venturi is connected to the inlet of the blower. All combustion air flows through the Venturi. The outlet of the 24 VAC gas valve connects directly to the side of the Venturi. Fuel gas flows from the outlet of the gas valve into the side of the Venturi directly. Inside the Venturi there is a cone shaped restrictor that constricts the air passage to the blower inlet. As air enters the constriction point it’s velocity
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL GAS VALVE The outlet of the gas valve is connected by flange directly to the side of the Venturi (page 14). There is no manifold gas line on the water heater. A gas orifice with gasket is fitted into the gas valve’s outlet flange. See the images below. Gas Valve Removal The gas valve must be removed to inspect the gas orifice. There are 3 - 5/32” hex head screws that secure the gas valve to the Venturi. Long T handle hex wre
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL GAS PRESSURE TESTING The water heater covered in this Service Manual is rated at 100,000 Btu/hr input. It is certified for elevations up to 10,100 feet (3079 meters) without adjustment. Call the technical support phone number shown on the water heater labeling before operating the water heater at higher elevations. Service Notes - Checking Gas Pressures Manifold and supply gas pressure can be measured at two test ports on the
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL GAS PRESSURES (CONT) CHECKING GAS PRESSURES (CONT) Typical manifold and supply gas pressures during: 5 Open the supply gas shut off valve - restore power - start a heating cycle. 1 Standby Mode 6 The rise in manifold pressure and corresponding 2 Pre-Purge Mode drop in supply gas pressure confirms the water heater’s gas valve is opening and gas is flowing 3 Heating Mode to the burner. 7 Record the supply and manifold gas pres
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL AIR PRESSURE SWITCHES Air pressure switch technical bulletins TB-A023-06 and TB-S023-06 explain air pressure switch construction and test procedures in detail. These technical bulletins are available on the manufacturers web site or by calling the technical support phone number shown on the water heater labeling. Construction and types of air pressure switches used on the water heater covered in this Service Manual are shown
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ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL AIR PRESSURE SWITCHES (CONT) The water heater covered in this Service Manual is factory equipped with three air pressure switches. These switches are used to provide verification or prove electrically that the blower is running and that the vent and intake air pipes are not blocked or restricted. The switches are located on the top of the water heater as shown in the illustration below. • BLOWER PROVER SWITCH TOP VIEW normall
