500 Tennessee Waltz Parkway Ashland City, TN 37015 USER’S MANUAL MODELS: VB/VW 1500, 2000 GAS-FIRED COPPER BOILERS FOR HYDRONIC HEATING AND HOT WATER SUPPLY • Operation • Maintenance • Limited Warranty SERIES 100/101 WARNING: If the information in this manual is not followed exactly, a fire or explosion may result causing property damage, personal injury or loss of life. — Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance.
TABLE OF contents Setting of the Test Mode................................................................. 13 TABLE OF CONTENTS........................................................................2 safe installation, use, and service....................................3 APPROVALS...........................................................................................3 GENERAL SAFETY...............................................................................4 INTRODUCTION ..........................
SAFE INSTALLATION, USE AND SERVICE The proper installation, use and servicing of this boiler is extremely important to your safety and the safety of others. Many safety-related messages and instructions have been provided in this manual and on your boiler to warn you and others of a potential injury hazard. Read and obey all safety messages and instructions throughout this manual.
GENERAL SAFETY Breathing Hazard - Carbon Monoxide Gas Special consideration must be taken with installation above 4500 feet. Please contact an A. O. Smith qualified service agent to obtain the proper setup and instructions before lighting. Failure to implement the proper setup will result in improper and inefficient operation of the appliance resulting in production of increased levels of carbon monoxide gas in excess of the safe limits which could result in serious personal injury or death.
introduction this manual and the local code authority having jurisdiction. These should be carefully followed in all cases. Authorities having jurisdiction should be consulted before installation begins if there are any questions regarding compliance with local, state or national codes. This design complies with the current edition of the ANSI Z21.13 - CSA 4.9 Standard for Gas Fired Low Pressure Steam and Hot Water Boilers.
INSTALLATION REQUIREMENTS FOR THE COMMONWEALTH OF MASSACHUSETTS For all side wall terminated, horizontally vented power vent, direct vent, and power direct vent gas fueled water heaters installed in every dwelling, building or structure used in whole or in part for residential purposes, including those owned or operated by the Commonwealth and where the side wall exhaust vent termination is less than seven (7) feet above finished grade in the area of the venting, including but not limited to decks and porch
VB/VW 1500/2000 SCHEMATIC DIAGRAM HOT 120VAC NEUTRAL 120VAC RTN R POWER POWER RELAY ON/OFF SWITCH RELAY COIL CONTACTS PUMP RELAY CONTACTS 20 AMP FUSE (PDB – F2) K8 (MCB-II) 10 AMP FUSE (PDB – F6) CIRCULATING PUMP (VW UNITS ONLY) PUMP RELAY COIL R K11 (MCB-II) K6 (MCB-II) K4 (MCB-II) IGNITER GAS VALVE K5 (MCB-II) BLOWER 15 AMP FUSE (PDB – F7) 0-10VDC PRIMARY + 120VAC - 3 AMP FUSE (PDB – F3) + 24VAC SECONDARY 7.
CIRCUIT CIRCUIT BOARD BOARD JUMPERS JUMPERS VB/VW VB/VW1500/2000 1500/2000W MCB-IIMCB-II – JP1 (not – JP1 used), (not used), JP2 (used JP2–(used 2.7A –igniter), 2.7A igniter), JP3 & JP4 JP3 (used & JP4–(used removed – removed for hipot fortest). hipot test). PDB – PDB JP1 (used – JP1–(used run selection, – run selection, JP2 & JP3 JP2 (used & JP3–(used – removed removed for hipot fortest). hipot test).
0WIRING WIRINGDIAGRAM DIAGRAM LEGEND LEGEND 120VAC 120VAC WIRING WIRING LOWLOW VOLTAGE VOLTAGE WIRING WIRING CAT-5 CAT-5 COMM COMM CABLE CABLE AVAILABLE AVAILABLE OPTION OPTION RANSFORMER TRANSFORMER 120/24 120/24 VACVAC 24VAC24VAC USER USER INTERFACE INTERFACE MODULE MODULE (UIM) (UIM) NOTE1: NOTE1: IF ANYIFOF ANY THE OFORIGINAL THE ORIGINAL WIRE AS WIRE SUPPLIED AS SUPPLIED WITH THE WITHAPPLIANCE THE APPLIANCE MUST MUST BE REPLACED, BE REPLACED, REPLACE REPLACE WITH EQUIVALNET WITH EQUIVALNET GAUGE GA
operation IMPORTANT Only a Certified Start-up agent should perform the initial firing of the boiler. At this time the user should not hesitate to ask the start-up technician any questions regarding the operation and maintenance of the unit. If you still have questions, please contact the factory or your local A.O. Smith representative. Lighting and Operating instructions are included with this manual.
TABLE 1. GAS AND ELECTRICAL CHARACTERISTICS Maximum Supply Pressure Minimum Supply Pressure Type of Gas Inches W.C. kPa Inches W.C. kPa Inches W.C. kPa VB/VW-1500,2000 Natural -.2 to - 4.9 -.04 to - 1.22 14.0 3.49 4.0 1.0 VB/VW-1500,2000 Propane -.2 to - 4.9 -.04 to - 1.22 14.0 3.49 8.0 2.0 Models Manifold Pressure Electrical Power: 120v, 60hz, and 30 amps.
LIGHTING AND OPERATING INSTRUCTIONS 12
ADJUSTMENT LOW FIRE SETTING NATURAL GAS 7.5 - 9.5% CO2 PROPANE 9.5 - 12.0% CO2 Set boiler to the “Test Mode Low,” as described above, to achieve minimum firing rate of the boiler. Check combustion readings using a combustion analyzer. If combustion readings are not in accordance with the chart shown above adjust as follows: remove the cap on the gas regulator using a slotted screwdriver. This will expose the offset adjustment screw.
INPUTS TO MCB Flame Sensor: Flame (MCB - required): Returns a signal to the microprocessor when flame is detected on the burner. If the flame rod is missing or shorted, the flame will not be detected. TEMPERATURE SENSORS: Temperature probes (MCB - outlet and either inlet or tank are required): The MCB accepts analog temperature inputs from up to three sensors (inlet, outlet, and tank).
MCB - Three position Dipswitch SW2: This dipswitch is similar to the FCB dipswitches described below, but with only three switches being used: the number of blower speeds (switch #3), Hi Gas option (switch #2) and a spare (switch #1). Only the blower speed and Hi Gas options are the required selection, within the MCB, see Figure 2.
• Temperature Screen: Displays the sensed temperatures of the Outlet, Inlet, and Tank probes. Also displayed is the calculated Delta T (Outlet minus Inlet) for the system. Shorted (“Short”) and disconnected (“----”) probes are also displayed. selected post-circulate time to cycle the hot water out of the boiler. The FCB is commanded to shut down and the Alarm output is turned on. The green LED turns off and the red “Service” turns on and off (flashes).
• this state until the MCB sends a command to clear the error, and the system returns to the idle state. 2. Scroll the “>” with the DOWN key next to USER SETTING SCREEN. 3. Press the SELECT key. Cold Purge State Cold purge occurs when the MCB micro commands the blower to go on before lighting to clear the unit of residual gases. This state normally lasts approximately 32 seconds but on a special situation can last up to 5 minutes.
• • • The software revision level of the MCB. Current Error Screen: Displays the last error that the system has detected plus a time stamp of when the error occurred. (The time stamp is based on the elapsed hours value at the time the error occurred. It is displayed in hours and minutes. This error remain displayed as long as it is still valid. When cleared it is moved to the Error History Screen. The system will automatically jump to this screen when an error is detected.
TROUBLESHOOTING IGNITION SYSTEM Fault Messages and Lockout Status (* = stage number: 1, 2, 3, or 4) Fault Displayed Description Red LED Lockout “Display Fail” Communications with UIM interrupted Continuous Auto Reset Check communication cable to UIM. Try moving to other Internal Communications connector on MCB. Also check the connectors where the cable is plugged in for best connecting wires.
Problem: Gas OK, no burner start up (both shutoff valves are open, fan turns) There is not enough gas to accommodate a start up. Turn throttle screw ½ turn counterclockwise and try to start again with more gas. TROUBLESHOOTING GAS VALVE Problem: Non-linear CO2 curve on adjusted boiler (deviation more than 3-6%) 1. Possible blockage at the air inlet that prevents uniform, constant air flow. 2. The gas inlet pressure is too low at full load.
in higher that normal operating temperatures and possible shortened service life. BURNER MAINTENANCE Qualified servicers should follow this procedure when the boiler’s burner needs cleaning. 1. Turn off the electrical power to the boiler and close the main manual gas shutoff valve(s). Allow the boiler parts to cool before disassembly. Any safety devices including low water cutoffs used in conjunction with this boiler should receive periodic (every six months) inspection to assure proper operation.
HEAT EXCHANGER PREVENTIVE MAINTENANCE lines with air or water and clear or replace the blocked portions of the line as necessary. Note that areas of the drain line which include a sag or low spot in the line will also form a condensate trap which can be removed by levelling the tube and does not indicate a blocked system. In most water supply systems solids exist. As the water is heated, these tend to drop out depositing as scale or lime.
LIMITED WARRANTY A. O. Smith Corporation, the warrantor, extends the following LIMITED WARRANTY to the owner of this boiler: 1. If within TEN years after initial installation of the boiler, a heat exchanger or gas burner should prove upon examination by the warrantor to be defective in material or workmanship, the warrantor, at his option will exchange or repair such part or portion. This term is reduced to FIVE years if this boiler is used for water heating purposes other than hydronic space heating. a.
500 Tennessee Waltz Parkway, Ashland City, TN 37015 Technical Support: 800-527-1953 • Parts: 800-433-2545 • Fax: 800-644-9306 www.hotwater.
