GAS-FIRED COPPER BOILERS FOR HYDRONIC HEATING AND HOT WATER SUPPLY • • • • INSTRUCTION MANUAL MODELS: VB/VW-500, 750 AND 1000 Installation Operation Maintenance Limited Warranty SERIES 200/201 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.
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 3
dimension and capacity data Minimum clearances to combustibles: • 4” (102mm) rear • 0” (0mm) top & sides • 6” (152mm) vent FIGURE 1. TABLE 1. - GAS AND ELECTRICAL CHARACTERISTICS Manifold Pressure Maximum Supply Pressure Minimum Supply Pressure Model Type of Gas Inches W.C. kPa Inches W.C. kPa Inches W.C. VB/VW-500, 750, 1000 NATURAL -2 to -3.5 -.5 to .9 14 3.44 4.0 kPa 2.0 VB/VW-500, 750, 1000 PROPANE -2 to -3.5 -.5 to .9 14 3.44 8.0 2.
capacity AND FLOW data TABLE 3. RECOVERY CAPACITIES. Model No.
contents SAFE INSTALLATION, USE AND SERVICE............................................2 GENERAL SAFETY......................................................................................3 dimension and capacity data..........................................................4 capacity AND FLOW data.....................................................................5 contents....................................................................................................6 introduction...................
doors open to ventilate, then call your gas supplier or service agent. Keep area clear until a service call has been made. Grounding Instructions This boiler must be grounded in accordance with the National Electrical Code and/or local codes. Boiler is polarity sensitive; correct wiring is imperative for proper operation. At times you may not be able to smell an LP gas leak. One cause is odor fade, which is a loss of the chemical odorant that gives LP gas its distinctive smell.
Control Components flue of the unit is restricted or blocked. The BFS is a normally closed switch that opens when positive pressure is placed on the switch because of any restriction to the exhaust venting. If the BFS is activated check and clear any obstructions causing the restriction.
Temperature Probe allows a boiler to sense the actual water temperature inside the storage tank or hydronic heating loop. The boiler will modulate its firing rate in response to the actual system temperature and load conditions. The control system displays the temperature sensed from the Remote Temperature Probe as the “Tank” temperature on the default Temperatures screen.
This ASME-rated valve has a discharge capacity that exceeds maximum boiler input rating and a pressure rating that does not exceed maximum working pressure shown on boiler rating plate. In addition, a CSA design-certified and ASME-rated temperature and pressure (T&P) relief valve must be installed on each and every water storage tank in hot water supply system. The T&P relief valve must comply with applicable construction provisions of Standard for Relief Valves for Hot Water Supply Systems, ANSI Z21.
Unconfined Space In buildings of conventional frame, brick or stone construction, unconfined spaces may provide adequate air for combustion. If the unconfined space is within a building of tight construction (buildings using the following construction: weather stripping, heavy insulation, caulking, vapor barrier, etc.), air for combustion, ventilation, and draft hood dilution must be obtained from outdoors or spaces freely communicating with the outdoors.
Outdoor Air Through Two Horizontal Ducts for the openings that provide fresh air into confined spaces only. Do not refer to these illustrations for the purpose of vent installation. See Venting Installation on page 18 for complete venting installation instructions. Outdoor Air Through Two Openings FIGURE 9C.
Air From Other Indoor Spaces The confined space should be provided with two permanent openings, one commencing within 12 inches (300 mm) of the top and one commencing within 12 inches (300 mm) of the bottom of the enclosure. See Figure 9E. Each opening should communicate directly with an additional room(s) of sufficient volume so that the combined volume of all spaces meets the criteria for an Unconfined Space.
Termination Clearances Sidewall Power Vent POWER VENT (using room air for combustion) EXTERIOR CLEARANCES FOR SIDEWALL VENT TERMINATION G V D H A v E L v B FI XE D CLOSED V F B B C OPERABLE V OPERABLE V B B FI XE D CLOSED M X V A V X V K J B V X VENT TERMINAL AIR SUPPLY INLET AREA WHERE TERMINAL IS NOT PERMITTED Figure 9F. Vent terminal clearances for “Power Vent” installations. Power Vent configurations use room air for combustion.
Termination Clearances Sidewall Direct Vent DIRECT VENT (using outdoor air for combustion) EXTERIOR CLEARANCES FOR SIDEWALL VENT TERMINATION G V D H A v E L v B FI XE D CLOSED V OPERABLE V F B B C OPERABLE V B B FI XE D CLOSED V M X V K J A X V B V VENT TERMINAL X AIR SUPPLY INLET AREA WHERE TERMINAL IS NOT PERMITTED Figure 9G. Vent terminal clearances for “Direct Vent” installations. Direct Vent configurations use outdoor air for combustion.
VENTING 2. Through-the-Wall Termination (TWT) - horiz ontal vent termination directly through an outside wall, see Figure 11A. 3. Horizontal Direct Vent - using TWT to exhaust flue products and PVC piping to bring combustion air to the boiler from the outside, see Figures 12 and 12C. 4. Vertical Direct Vent - using a vertical vent termination to exhaust flue products and PVC piping to bring combustion air to the boiler from outside, see Figures 12A and 12B.
Venting Supports 4. Maintain a minimum of 6 feet (2.0m) separation between the air intake and the exhaust terminals. Care must be taken in the installation of the venting system that adequate support is maintained throughout the installation process. When extending more than 10 feet (3.0m) vertically, vertical support kits are required once every 10 feet (3.0m) of vertical run. Vertical support is also required immediately after any transition (elbow, tee, etc.) to vertical of over 10 feet (3.
NOTES: If the exhaust vent terminal is within 10’ (3.0m) of a wall or parapet, it must extend a minimum of 2’ (610mm) above the wall or parapet. Joints are not joined to show vent pipe orientation. FIGURE 11. VERTICAL TERMINATION. NOTES: Joints are not joined to show vent pipe orientation. FIGURE 11A. HORIZONTAL THROUGH THE WALL TERMINATION (TWT).
1. The Air-Intake System (AIS) must terminate with the venting equipment provided with the boiler, Refer to the parts list for required direct vent parts. Direct Vent Installation Requirements Follow the guidelines in the “HORIZONTAL INSTALLATION REQUIREMENTS” section for the exhausting of flue products. 2. The AIT shall not be located less than 3 feet (1.0m) below any exhaust vent within 10 feet (3.0m), see “HORIZONTAL INSTALLATION REQUIREMENTS” section. IMPORTANT 3.
NOTE: Joints are not joined to show vent pipe orientation. CAUTION Direct venting into dead air spaces such as alleys, atriums, and inside corners can cause recirculation of flue gases. Recirculation of flue gases will cause sooting, premature failure of the heat exchanger and icing of the combustion air intake during severe cold weather. To prevent the recirculation of flue gases, maintain as much distance as possible between the combustion air intake and the exhaust vent terminal. FIGURE 12.
Option B (Figures 12B & 12C) assures no recirculation of flue gases. 70 EQUIVALENT FEET (27.4m) OF VENTING (MAX.) AL 29-4C® AIR INTAKE TERMINAL HORIZONTAL AIR INTAKE NOTES: PVC PIPE 70 EQUIVALENT FEET (27.4m) • IF THE EXHAUST VENT TERMINAL IS WITHIN 10’ (3.0m) OF A WALL OR A PARAPET, IT MIUST EXTEND A MINIMUM OF 2’ (0.6m) ABOVE THE WALL OR PARAPET.
system installation General If the system is to be filled with water for testing or other purposes during cold weather and before actual operation, care must be taken to prevent a downdraft entering the boiler or freezing air from contacting the system. Failure to do so may cause the water in the system to freeze with resulting damage to the system. Damage due to freezing is not covered by the warranty. Good practice requires that all heavy piping, etc., be supported.
7. SYSTEM CONTROLLER Controlling of these systems is decided mainly by the type of building system controlling desired. A single boiler installation might be controlled directly from space temperature thermostat(s). Multiple boiler installations are more effective when the boilers are sequenced in and out of operation by some form of main water temperature controller. With one or two boilers, individual control settings at progressive temperature may be used.
This is accomplished by changing two dipswitch settings on the MCB. First, dipswitch “4” must be set to the “ON” position to designate the remote probe as the controlling probe. Second, dipswitch “1” must be set to the “OFF” position to limit the maximum remote probe temperature for VW applications. Also, make sure dipswitch “1” is set to the “OFF” position, which sets the outlet temperature for VW applications. Failure to do this will void the warranty.
• INSTALL IN ACCORDANCE WITH ALL LOCAL CODES. • WHEN BLOW DOWN VALVE IS REQUIRED, INSTALL IN PLACE OF THE DRAIN VALVE SHOWN. FIGURE 13. TYPICAL PRIMARY, SECONDARY PIPING. TYPICAL PRIMARY, SECONDARY PIPING. DANGER TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERATURE AT FIXTURES. IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO FIXTURES, SEE TABLE 8..
• WHEN BLOW DOWN VALVE IS REQUIRED, INSTALL IN PLACE OF THE DRAIN VALVE SHOWN. • INSTALL IN ACCORDANCE WITH ALL LOCAL CODES. FIGURE 14. DANGER TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERATURE AT FIXTURES. IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO FIXTURES, SEE TABLE 8.
• WHEN BLOW DOWN VALVE IS REQUIRED, INSTALL IN PLACE OF THE DRAIN VALVE SHOWN. • INSTALL IN ACCORDANCE WITH ALL LOCAL CODES. FIGURE 15. ONE VF (MODEL VW) HOT WATER SUPPLY BOILER WITH HORIZONTAL TANK TEMPERATURE SETTING SHOULD NOT EXCEED SAFE USE TEMPERATURE AT FIXTURES. IF HIGHER PREHEAT TEMPERATURES ARE NECESSARY TO OBTAIN ADEQUATE BOOSTER OUTPUT, ADD AN ANTI-SCALD VALVE FOR HOT WATER SUPPLIED TO FIXTURES, SEE TABLE 8.
Wiring There are five (5) electrical connections that must be made for the unit to operate correctly: 1. BLACK (No Stripe) 120V HOT 2. WHITE 120V NEUTRAL 3. GREEN GROUND 4. (2) TANK PROBE OR (2) ENABLE/DISABLE*** Label all wires prior to disconnection when servicing controls. Wiring errors can cause improper and dangerous operation. *** Enable/disable can also be used with a 24 volt thermostat. Do not use tank probe when using thermostat. Verify proper operation after servicing.
10 (3.05) 680,000 199 1,400,000 410 2,100,000 615 3,950,000 1,157 6,300,000 1,845 11,000,000 3,222 23,000,000 6,736 20 (6.1) 465,000 136 950,000 278 1,460,000 428 2,750,000 805 4,350,000 1,274 7,700,000 2,255 15,800,000 4,627 29 Nominal Iron Pipe Size (Inches) 1 BTU/hr kW 1 1/4 BTU/hr kW 1 1/2 BTU/hr kW 2 BTU/hr kW 2 1/2 BTU/hr kW 3 BTU/hr kW 4 BTU/hr kW 10 (3.05) 1,060,800 311 2,184,000 640 3,276,000 959 6,162,000 1,805 9,828,000 2,878 17,160,000 5,026 35,880,000 10,508 20 (6.
FIGURE 17.
VB/VW-500, 750 & 1000 SCHEMATIC DIAGRAM FIGURE 18.
operation Important Only qualified personnel shall perform the initial firing of the boiler. At this time the user should not hesitate to ask the service agent 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.
The boiler should be located in an area that is inaccessible to the general public. Never allow small children to use a hot water tap or to draw their own bath water. Never leave a child or handicapped person unattended in a bathtub or shower. TABLE 8. Risk of Scalds.
MCB - Ten Position Dipswitch: Dipswitch configurations are READ ONLY ON POWER UP. These switches are only to be set at the factory or by authorized trained personnel! Once set the boiler will operate according to the chosen options. If a switch is changed, power must be cycled before the change will take effect. The status of all dipswitches can be observed on the system status screen on the UIM. TABLE 9.
LIGHTING & OPERATION INSTRUCTIONS FOR MODELS VB/VW 500, 750 AND 1000: 36
Adjustment TABLE 12. - LOW FIRE SETTING NATURAL 6.5 - 7.5% CO2 PROPANE 7.5 - 8.5% 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: TEMPERATURE SENSORS: Flame (MCB - required): Returns a signal to the microprocessor if flame is detected on the burner. If the flame rod is missing or shorted, the flame will not be detected. 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). OUTPUTS FROM MCB MRHL (Manual Reset HIGH LIMIT): The MRHL is a hi-limit switch located inside the outlet probe.
NOTE: If the unit powers up with the number of stages selected by dip switches exceeding the number of FCBs, the MCB will detect this condition and go into a hard lockout. After changing the dipswitches, the power must be cycled off and back on to accept any changes. Example of Dipswitch configuration: VB model, 1ignition trial, not used, tank / remote probe, no power vent, No LWCO, no low gas pressure, modulation, not used, not used.
UIM Operating Procedures after the Igniter is turned on until the igniter is turned off and an off condition at all other times. • Flame - for an on condition approximately 5 seconds after the gas valve is turned on until the valve is turned off and at all other times for an off condition. Control Status Screen: Displays the status that the MCB micros are in. The MCB has 5 possible states and the FCB have 9.
The process waits in this state until the call for heat is satisfied, the thermostat input is opened, or a fault occurs. When heat is satisfied, the sequence continues to Post-Purge and then back to Idle. If three tries for ignition has been selected on the MCB dipswitch and flame is not detected at the appropriate time, then the sequence moves to the Inter-Purge state for 15 seconds and the FCB heat sequence is repeated.
Elapsed hours of operation (Total time system has been powered up) Use the following procedure to change the automatically resettable High Limit Setpoint: 1. Press the MENU key. Number of running minutes (Number of minutes system has been in the run mode) 2. Scroll the “>” with the DOWN key next to USER SETTING SCREEN. kBtu rating of the boiler (0 to 5750kBtu in 10kBtu increments) 3. Press the SELECT key. The software revision level of the MCB. • 4.
• Up and Down Keys: has been detected and the system has stopped running. It is on continuously for soft faults and flashes for hard faults. The Yellow LED indicates that the boiler is in a ready mode waiting for a call for heat command. When on continuously the Green LED indicates that the system is in the heating mode. If it is flashing it indicates that the UIM is in the initialization mode and the touch switches are being calibrated.
TROUBLESHOOTING IGNITION SYSTEM Fault Messages and Lockout Status (* = stage number: 1, 2, 3, or 4) Fault Displayed Description Red LED “Display Fail” Lockout 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. “Comm. Fail Stg.*” Communications with FCB interrupted Continuous Auto Reset Same as above.
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.
or on the blower and motor. Buildups of dirt and lint on the blower and motor can create excessive loads on the motor resulting 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.
Heat Exchanger Preventative 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.
notes 48
notes 49
notes 50
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 shall 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 Phone: 800-433-2545 www.hotwater.com E-Mail: parts@hotwater.
