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Installation and Operation Instructions

Document 2100

H0210400-

Installation
and Operation
Instructions for

Natco
Fire-Coil

Model 175-400
Volume Water Heaters

FOR YOUR SAFETY: This product must be installed and serviced by a professional service technician,
qualified in hot water heater installation and maintenance. Improper installation and/or operation could
create carbon monoxide gas in flue gases which could cause serious injury, property damage, or death.
Improper installation and/or operation will void the warranty.

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.

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 nearby 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 gas
supplier.

N

ATCO

N

ATCO

Summary of Contents for Fire-Coil 175-400

Page 1: ...on will void the warranty 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 WHAT TO DO IF YOU SMELL GAS Do not try to light any appliance Do not touch any electrical switch do not use...

Page 2: ...mperature Controls 15 3D Adjustment for Minimum Input Rate models with modulating gas valve 18 3E Hi Limit Switch Checkout 18 3F Shut Down Procedure 18 SECTION 4 Maintenance 4A General Instructions 18 4B Replacement of Gas Controls 19 4C Heat Exchanger 20 4C 1 Inspecting the Heat Exchanger 20 4C 2 Cleaning the Heat Exchanger 21 SECTION 5 Troubleshooting 5A Gas Pressure Tests 21 5A 1 Checking the M...

Page 3: ...number and model this information can be found on the rating plate installation date and name of the installer Shipping costs are not included in the warranty coverage Some accessory items are shipped in separate packages Inspect everything for damage immediately upon delivery and advise the transporter of any shortages or damage Any such claims should be filed with the transporter The transporter...

Page 4: ...dance with CAN1 B149 1 or 2 and local codes The authority having jurisdiction may require the installation conform to the Standard for Controls and Safety Devices for Automatically Fired Heaters ANSI ASME CSD 1 Any changes to the heater gas controls gas orifices wiring or draft diverter may void the warranty If field conditions require a change to any of the above consult the factory All gas fired...

Page 5: ...otal volume of all the gas fired appliances within the enclosure Alcove Installation acceptable An alcove suitable for the installation of a heater is a restricted section of a room not separated from the room by a door or partition and which meets the minimum clearances specified in this manual When the ceiling height exceeds 8 feet you are only allowed to consider 8 feet when calculating the tot...

Page 6: ...s Flashing 4x4 Stringer Roof Base Rail 20 Gauge Galvanized Sheet Metal Cap Roofing Avoid locations where wind deflection off nearby structures might cause wind loading and downdraft conditions Where downdraft conditions exist locate the heater at least 3 feet 0 91 m from the structure 2C 3 Flooring Typical Installation Do not install the heater directly on carpeting without placing a non combustib...

Page 7: ... fans can pick up exhaust flue products from the heater and return them inside the building creating a possible health hazard Avoid horizontal runs of the vent pipe and 90 degree elbows reductions and restrictions Horizontal runs should have at least a 1 4 inch 6 3 mm rise per foot in the direction of flow Support a vent connector for the design and weight of the material used to maintain clearanc...

Page 8: ... 2 If there is a vent cap or drafthood installed they must be removed before removing the grate top assembly On indoor installations sizes 175 250 the drafthood switch must be disconnected at the left side of the heater 3 If the unit is in the low profile outdoor configuration remove the hex head screws see Figure 15 and lift the grate top assembly straight up 4 Remove the screws that fastens the ...

Page 9: ...DUIT GAP CLOSURE GROMMET DRAIN VALVE METAL CHANNEL FOR CAPILLARY TUBE TERMINAL STRIP HEAT EXCHANGER ASSEMBLY GAP CLOSURE DRAIN PLUG DRAIN VALVE REAR TILE COVER HEX HEAD SCREWS MANUAL RESET HIGH LIMIT SWITCH BOX Figure 15 Heat exchanger reversal 2 Stage Operating Controller Inlet Outlet High Limit Header Modulating if installed Retaining Clip ...

Page 10: ...F 2 Water Chemistry Natco equipment is designed to be used in a variety of water conditions With the proper pump the water velocity in the heat exchanger tubes is kept high enough to prevent scaling from hard water yet low enough to avoid erosion by soft water NOTE It is possible to have hard and soft water in the same city Check with the local water companies Figure 18 Hole location left side Att...

Page 11: ...07 kPa it could damage the heater through lack of circulation If for any reason the water is turned off temporarily to service the equipment for example airlock could be a problem when the heater If an installer sees damage to any water handling equipment at the installation site it should be repaired as soon as possible to help reduce maintenance costs If there is erosion resize the pump to reduc...

Page 12: ...2 1 13 3 4 1 19 11 Hard 46 2 9 23 4 7 1 14 8 4 Soft 17 0 7 11 1 3 4 37 21 Normal 17 0 7 11 1 3 4 37 21 Hard 23 1 5 19 5 5 9 27 15 Pressure drop includes head loss of heat exchanger and through 30 feet 9 1 m of pipe and normal fittings when heater is installed with storage tank Pipe and fittings are assumed to be 1 1 2 inch 38 mm Remote Temperature Control for Heater Main Circulating Loop With Own ...

Page 13: ...ank Opening Not Available To Drain Heater Service Valve Pump To Drain Conventional Tank Figure 21 Hot water supply with horizontal tank Note Heavy line indicates heater to tank circulation loop Hot Water Return from Building Hot Water to Building Check Valve Bldg Loop Circ Pump Cold Water 24 Inch Min Drain Conventional Tank Heater To Drain Service Valves Figure 20 Hot water supply with vertical ta...

Page 14: ...nes Under certain circumstances thermal circulation will occur in the cold water pipe supplying the water to the heating system This happens in a multi story building when the cold water pipe rises from its connection to the system To correct the problem a check valve in the cold water line supplying the heater will prevent thermal circulation and a small expansion tank will permit heated water to...

Page 15: ...e figures in Table 5 should be used to size the gas piping from the gas meter to the heater Figure 23 T Fitting and sediment trap MANUAL SHUT OFF VALVE GAS SUPPLY INLET T FITTING 3 76 mm MIN UNION NIPPLE CAP TO BOILER INLET Distance from Gas Meter 0 100 feet 100 200 feet 200 300 feet 0 30 m 30 60 m 60 90 m Heater Nat Nat Nat Size in mm in mm in mm 175 1 00 25 1 25 32 1 25 32 250 1 25 32 1 25 32 1 ...

Page 16: ...interlock the pump and heater so the heater cannot come on unless the pump is running 4 Connect all field installed devices draft switches relays timers outdoor temperature reset devices etc see Figs 18 and 19 to the heater wiring at points labeled Field Interlock 2I Combined Space Heating Potable Water Heating Systems 2I 1 Combined Space Heating The VW and PW heaters are not to be used as a sourc...

Page 17: ... electric power to the appliance to off 5 Turn manual gas valve off 6 Wait 5 minutes to clear out any gas then smell for gas including near the floor Be sure to smell next to the floor because some types of gas are heavier than air and will settle on the floor Caution This heater is equipped with an ignition device which automatically lights the burner Do not try to light the burner by hand 7 Turn...

Page 18: ...al example of wiring schematic System 1 IGNITION SYSTEM NO 1 STANDING PILOT ON OFF OR MECHANICAL MODULATION Volume Water Heaters 325 400 Version B Natural or Propane Gas PUMP INCLUDED ON PW MODELS FIELD SUPPLIED ON VW MODELS ...

Page 19: ...Figure 26 Typical example of wiring schematic System 12 IGNITION SYSTEM NO 12 ELECTRONIC IGNITION ON OFF OR MECHANICAL MODULATION Volume Water Heaters 325 400 Version B Natural or Propane Gas PUMP INCLUDED ON PW MODELS FIELD SUPPLIED ON VW MODELS ...

Page 20: ...mmable liquids and vapors 6 Be sure all combustion air and ventilation openings are not blocked 7 Check for black carbon soot buildup on the external surfaces of the heat exchanger every 6 months 8 Do not use the heater if any part has been under water Replace anypart of the control system and any gas control which has been under water NOTE After installation and first startup check the heat excha...

Page 21: ...ttempt to repair the gas valve Such attempts will void the warranty and could lead to dangerous results If the gas valve is found to be defective replace it by following these instructions 1 Turn off electrical power to the heater 2 Turn off the main gas supply at the manual gas cock outside the heater jacket or at the meter 3 Remove the front access door on the heater 4 Turn off the gas valve to ...

Page 22: ...aks using a soap solution Caution Since some leak test solutions including soap and water may cause corrosion or stress cracking rinse the piping with water after testing 22 Reconnect the electrical wires to the gas valve in accordance with the wiring diagram found on the inside of the heater 23 Install the front access door on the heater 24 Turn all electrical power to the heater on 4C HEAT EXCHA...

Page 23: ...ively starting with the two center bolts Maximum torque is 20 foot pounds 27 Nm Do not over torque 8 Pressure test the heat exchanger for leaks with city water supply before re installing see Figure 32 9 When placing the heat exchanger back in the heater carefully hold the refractory insulation blocks apart and lower the heat exchanger into place Be sure the sheet metal covers which protect the in...

Page 24: ...the inside of the heater 11 Disconnect the manometer tubing from the gas valve and replace the 1 8 inch NPT 3 2 mm fitting with the original plug 5B Electrical Troubleshooting This section describes procedures for checking the electrical power and control components of the heater Read all of these procedures before starting repairs Problems with heaters not firing are usually caused by something r...

Page 25: ...erminal see Figure 34 The voltmeter should read 20 to 28VAC 3 If the voltmeter does not show voltage check the electrical power supply 4 If the voltage is less than 20VAC the electrical circuit to the heater may be supplying less than 103VAC This could be due to high pump load or air conditioners or other appliances on the circuit 5B 3 Testing the Electrical Power Supply The electrical components ...

Page 26: ...k fire If the water flow is too low the switch remains open and prevents the heater from firing regardless of the temperature control setting The flow switch is factory mounted and wired Never attempt to repair the flow switch If the flow switch is found to be defective replace the flow switch To test the flow switch 1 Remove cap from flow switch 2 Touch a voltmeter lead to each terminal of the fl...

Page 27: ...er from firing 4 Make sure the pilot burner is positioned next to the main burner see Figure 38 and there is no soot or dirt on it 5 Make sure the electrode part of pilot assembly is clean the terminal connection is tight and the stainless steel lead is at least 3 8 inch 9 5 mm from the heater chassis and other metal parts 6 Check for proper spark gap 5B 10 Testing the High Voltage Ignition Lead C...

Page 28: ...not show voltage replace the ignition control 6 If the voltmeter reads 20 to 28VAC but there is no pilot ignition check for a air in gas lines b restrictions in gas line valve or pilot tubing c clogged pilot orifice If these are correct then replace gas valve see Section 4C WARNING Never attempt to repair the gas valve Such attempts will void the warranty and could lead to dangerous results 5B 14 ...

Page 29: ...tage at one terminal and not the other examine the external control It may require service or replacement 2 If everything appears all right measure flame sensing current by connecting a direct current DC microamp meter between terminal No 12 and the GND BURNER terminal on the ignition control see Figure 41 NOTE Separate the microamp meter leads from each other and clear the heater chassis for most...

Page 30: ... 16 Fuse 2 Amp E0084400 17 Switch Flow Outdoor E0013000 18 Fusible Link 175 thru 250 E0099403 19 Switch Toggle On Off E0077000 20 Switch Hi Limit Manual Reset E0015900 Item Description Part Number 21 Temp Controller Auto Reset E0014400 Model 250 E0141302 24 Switch Drafthood E0121000 VENT SYSTEM 26 Vent Cap R0318602 05 27 Drafthood R0318702 05 28 Drafthood Vent Cap Adapter Plate 10535302 05 29 Flue...

Page 31: ...0071700 61 Bushing Brass P0018500 62 Bracket Holddown 10726300 63 Clamp Holddown 10726200 Item Description Part Number JACKET COMPONENTS 64 Jacket Assembly 10568302 05 65 Door 10448902 05 66 Deflector Rear 10563706 10 67 Deflector Lower 10563606 10 68 Gap Closure In Out 10448202 69 Gap Closure Return 10448302 ...

Page 32: ...National Combustion Company Inc 104 07 180th Street Jamaica NY 11433 718 291 8400 FAX 718 291 6870 Litho in U S A 0610 H0210400A ...

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