Installation and Operating Instructions for Natco …

1 water Heater ManualDocument 2105 Installationand OperatingInstructions forNatcoFire CoilMIGHTYTHERMM odelsVW, PW and IWVolume water HeatersSizes 500-1825 MIGHTYTHERMFOR YOUR SAFETYDo not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other Installation , adjustment, alteration, service or maintenance can cause injury or property damage. Refer to thismanual. For assistance or additional information consult a qualified installer, service agency or the gas YOUR SAFETY - WHAT TO DO IF YOU SMELL GAS 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 telephone. Follow the gas suppplier s information. If you cannot reach your gas supplier, call the fire Instructions are to be stored in the pocket provided on the 1.

2 GENERAL INFORMATION Page1A. 31B. Heater Identification .. 31C. Flow Requirements .. 41D. water Chemistry .. 4 SECTION 2. INSTALLATION2A. Heater 42B. Installation of Indoor heaters .. 52B-1 Combustion Air Supply .. 52B-2 Venting .. 62C. Installation of Outdoor heaters .. 72D. Gas Supply and Piping .. 72E. Electrical 82F. water Piping of System .. 92G. water 92H. Pump Performance and Installation .. Pressure .. 142J. Tank 142K. Two-Temperature 17 SECTION 3. OPERATION3A. Controls General .. 173B. Initial 193C. To Start Up System .. 193D. To Turn Off Heater .. 203E. To Shut Down System .. 20 SECTION 4. MAINTENANCE .. 20 SECTION 5. TROUBLESHOOTING ANDANALYSIS OF SERVICE PROBLEMS .. 21 TABLES AND FIGUREST able 4 Table Recommended Air SupplyTo Heater.

3 6 Table III. Gas Piping Sizes .. 8 Table IV. Pump Performance Requirements .. 14 Table ValveTemperature 18 Figure 1 Boiler 3 Figure 2 Typical Heater Installation with Basefor Combustible Floors (Ex. A) .. 5 Figure 3 Typical Heater Installation with Basefor Combustible Floors (Ex. B) .. 5 Figure 4 Typical Heater Installation with Basefor Combustible Floors (Ex. C) .. 5 Figure 5 Installation on Concrete Blocksor Tile .. 5 Figure 6 Alcove 6 Figure 7 Incorrect Outdoor Installation .. 7 Figure 8T-Fitting Sediment Trap Installation .. 8 Figure 9 Pressure Relief Valve Location .. 9 Figure 10 Tempering Valve 9 Figure 11 Hot water Supply System forModels VW and PW .. 11 Figure 12 Hot water Supply System usingModel PW with Dual Tanks,Building Loop Return andCirculating 12 Figure 13 Split System Piping for Model IW.

4 12 Figure 14 Dual Installation Piping Diagramfor Model IW .. 13 Figure 15 Single Installation PipingDiagram for Model IW .. 13 Figure 16 Two Temperature Hot WaterSupply System (Model VW orPW) Vertical/Horizontal 15 Figure 17 Two Temperature Hot WaterSupply System w/VerticalTank for Models VW and PWWater heaters .. 16 Figure 18 Controls Location .. 16 Figure 19 Control Components .. 18 Figure 20 Pilot Burners ( ) .. 18 Figure 21 Gas Manual Valves .. 19 Figure 22 Pilot Safety Relay .. 20 Figure 23 Main Burner Flame Pattern .. 20 Section 1 General manual provides information for theinstallation and operation of Natco volume waterheaters. It is strongly recommended that allapplication and Installation procedures be reviewedcompletely before proceeding with the the Natco factory, or local factoryrepresentative, with any problems or questionsregarding this equipment.

5 Experience has shown thatmost problems are caused by improper accessory items are shipped in separatepackages. Verify receipt of all packages listed on thepackage slip. Inspect everything for possible damageupon delivery, and inform the carrier of any shortagesor impairments. Any such claims should be filed withthe carrier. The carrier, not the shipper, is responsiblefor shortages and damage to the shipment whethervisible or WARNING:All volume water heaters must be installed inaccordance with the procedures outlined in thismanual. The warranty does not apply to heaters notinstalled or operated in accordance with theseprocedures. Consult local building and safety codesbefore proceeding with work. The Installation mustconform to the requirements of the authority havingjurisdiction or, in the absence of such requirements, tothe latest edition of the National Fuel Gas Code;ANS1 , National Electrical Code ANSI/NFPA70 and/or in Canada CAN1-B149 1 Boiler ConfigurationWhen required by the authority having jurisdiction, theinstallation must conform to American Society ofMechanical Engineers safety codes for controls andsafety devices for automatically fired heaters , and in Canada CGA Any modification tothe water heater, its gas controls, gas orifices, wiringor draft diverter may void the Natco warranty.

6 If fieldconditions require such modifications, consult IdentificationConsult rating plate on the heater. The followingexample simplifies the heater identification. 1 2 3 4 5 6 P W 1 6 7 0 I N 09 L(1)Basic heater model.*(2)Input rate X 1000 BTU/hr.(3)Indoor (I) or Outdoor (E) Installation .(4)Gas type: Natural (N) or Propane (P).(5)Ignition system: (09) or continuous pilot(16).**(6)Firing rate: On/Off (C), 2-stage (K), 4-stage (L),or Mech. Mod (H).*Model VW water heaters for use with separatestorage tank. There must be a field installed pump tocirculate water between the heater and the storagetank.*Model PW water heaters are basically the same asthe VW series except that the PW heaters come withintegrally mount pumps.

7 *Model IW water heaters are tankless instantaneousheaters, complete with mount pump for use inapplications having a suitable diversity in heater load.**Special Options: (04) 115 volts or (08)IRI ControlsNatco commercial water heaters are available intwo models: an indoor version and an outdoorversion. Both are available from the factory. SeeFigure PlacementThe heater must be placed to provide specificclearances on all sides for maintenance andinspection. There must also be minimum distancesmaintained from combustible surfaces. Theseclearances also apply to non-combustible materialsbecause the heater requires air circulation for I. Minimum Boiler ClearancesFrom Combustible Surfaces Clearance Indoor Outdoor From (Inches) (Inches) Top 30 unobstruct water Conn Side 12 24 Opposite Side 6 24 Front Alcove unobstruct Rear 8 24 Vent Pipe* 6 -- Hot water Pipes Per Code Per Code *Using type B Vent (refer to Manufacturer s Instructions )Heater should be mounted on a level surface.

8 Anintegral combustible flooring base is provided asstandard equipment on outdoor models. Indoormodels can be installed on a combustible floor with aspecial base assembly which is available from thefactory. See rating plate for part number of the not install a heater on the National Fuel Gas Code, ANSI ,it is permissible to place the heater on floors otherthan non-combustible when the Installation complieswith the American Insurance Code. Figures 2, 3, 4and 5 show common Installation on RequirementsFor proper operation, all low volume hot waterheaters must have continuous flow through the heatexchanger when firing. The system pump must becapable of developing sufficient pressure to overcomethe resistance of the heater plus the entire circulatingsystem at the designed flow ChemistryNatco equipment is designed for use in a widevariety of water conditions.

9 The water velocitymaintained in the heat exchanger tubes is kept highenough to prevent scaling from hard water and lowenough to avoid corrosion from soft water . Ninety-fivepercent of the urban areas in the country have waterthat is compatible with this equipment, but in someareas a water supply will contain a large quantity ofscaling chemicals or the water may be extremely softand corrosive. In rare situations the water will containboth scaling chemicals and corrosive chemicals suchas calcium or sodium chloride. These conditions maybe the result of a nearby well or pumping station andthe particular condition may not be characteristic ofthe entire city water an installer observes damage from theseconditions to any water handling equipment in thearea, a factory representative should be contactedimmediately for assistance in minimizing maintenancecosts.

10 If erosion is present, the pump impeller can bereplaced to reduce water velocity. If scalingconditions are bad, tube cleaning maintenanceschedules can be established to prevent tube burn-out and cracking. Neglecting the problem could meanserious damage to the heater and water can be recognized as a layer depositedon the inner walls of the tube which reduces the innerdiameter of the tube. Scale can be any color ortexture; smooth or rough, granular or of erosion are generally pitting, cavitation,ridges and islands on the inner walls of the this condition results from extremely soft watersources, or as a result of a water softening program,the internal copper surfaces will be extremely chemicals, such as chlorine or chlorides in thewater, will cause dark surfaces of areas where the water supply is extremelycorrosive, it is advisable to order the heater withcupro-nickel tubes in the From Scaling, Corrosion, or Erosion isNot Covered by the 5 Installation on Concrete Blocks or TileFigure 2 Typical Heater Installation with Base forCombustible Floors, Example AFigure 3 Typical Heater Installation with Base forCombustible Floors.