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provided with an appropriate transformer.

2.

Wire the heater and pump exactly as shown in
the wiring diagram supplied with the heater.

3.

The pump and heater must be electrically
interlocked so the heater cannot come on unless
the pump is running.

4.

All field installed electrical safety devices and all
field installed devices (draft switches, relays,
timers, outdoor temperature reset devices, etc.)
can be connected to the heater wiring at points
shown in the wiring diagram designated “Field
Interlock”.

2F.

Water Piping of System

1.

Be sure to provide valves at the inlet and outlet of
the boiler so it can be readily isolated for service.
A butterfly or similar type of valve is
recommended.

2.

The pressure relief valve installed in the tapped
opening provided in the outlet header (See
Figure 9), must be piped, but not fastened, to a
drain or floor sink.  The drain pipe must be the
same size as the valve outlet and must pitch
downward from the valve.

Special attention must be given to relief valve
settings in installations where the heater is
located on the ground floor of a tall building.  The
static pressure of the system is elevated and
could cause the relief valve to leak.  Where no
special setting of the relief valve is ordered, the
factory will furnish a 125 psi setting
.  Never
reduce the relief valve openings.

Figure 10 – Tempering Valve Installation

9

Figure 9 – Pressure Relief Valve Location

Pressure
Relief
Valve

Hot 
Water

Hot 
Water
Storage
Tank

Floor

Automatic
Tempering
Valve

Cold  
Water

Tempered  Water

24"

3.

Pressure relief valve lever must be tripped at
least once a year to insure that waterways are
clean.  When manually operating lever, water will
discharge through drain line. Precautions must be
taken to avoid contact with hot water and water
damage.

4.

The weight of all water and gas piping should be
supported by suitable hangers or floor stands.

5.

Check piping diagrams with local applicable
plumbing, heating and building safety codes.

6.

All two-temperature systems using temperature
valves must have forced recirculation in the low
temperature building loop.

7.

A check valve installed at the hot water inlet to
the tempering valve will prevent cold water from
being drawn in reverse through the tempering
valve into the hot water.

8.

When installing a tempering valve, place at
bottom of antithermosyphon loop at least 24" high
to prevent excessive hot water from entering
mixed water supply.  Bring the cold water supply
up from the floor to the valve. (See Figure 10)

2G.

Water Expansion

When cold water is heated the water expands.  If

no water is being used during the heat-up period the
expanded water will normally back up into the city
mains.

A water pressure reducing valve installed in the

incoming cold water line may act as a check valve
and prevent the expanded water from moving
backward.  This will cause pressure to rise in the
heater, which will be relieved by the pressure relief
valve.

If the relief valve pops frequently a mineral

deposit may build up on the valve seat, causing it to

Summary of Contents for Fire Coil IW 1010

Page 1: ...ance can cause injury or property damage Refer to this manual For assistance or additional information consult a qualified installer service agency or the gas supplier FOR 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 sup...

Page 2: ...pical Heater Installation with Base for Combustible Floors Ex A 5 Figure 3 Typical Heater Installation with Base for Combustible Floors Ex B 5 Figure 4 Typical Heater Installation with Base for Combustible Floors Ex C 5 Figure 5 Installation on Concrete Blocks or Tile 5 Figure 6 Alcove Installation 6 Figure 7 Incorrect Outdoor Installation 7 Figure 8 T Fitting Sediment Trap Installation 8 Figure 9...

Page 3: ...tional Electrical Code ANSI NFPA 70 and or in Canada CAN1 B149 requirement 3 Figure 1 Boiler Configuration When required by the authority having jurisdiction the installation must conform to American Society of Mechanical Engineers safety codes for controls and safety devices for automatically fired heaters No CSD 1 and in Canada CGA 3 3 Any modification to the water heater its gas controls gas or...

Page 4: ...xchanger tubes is kept high enough to prevent scaling from hard water and low enough to avoid corrosion from soft water Ninety five percent of the urban areas in the country have water that is compatible with this equipment but in some areas a water supply will contain a large quantity of scaling chemicals or the water may be extremely soft and corrosive In rare situations the water will contain b...

Page 5: ...bustion air supply may result in incomplete combustion sooting of the heat exchanger and unsafe operation of the heater 2 In general these requirements specify that small heater rooms should be provided with two permanent air supply openings communicating directly through the wall to outside air one within Base For Combustible Floors Concrete Slab 4 Minimum Concrete Slab Must Extend Out A Minimum ...

Page 6: ...penings one at floor level and one at the ceiling so the total net free area could be double the figures indicated For special conditions refer to the latest edition of ANSI Z223 1 or in Canada CAN1 B149 1 and 2 Consult factory if not communicating directly through the walls with the outdoors Note Check with louver manufacturers for net free area of louvers Correct for screen resistance to the net...

Page 7: ...inch of vent diameter Longer total lengths shown in venting tables are based on maximum capacity not condensation factors 7 When the installation of a draft fan is necessary in connecting a venting system to a Natco heater the installation should be engineered by competent personnel following good engineering practices The draft fan supplier should be consulted for correct size The installation sh...

Page 8: ...city to properly measure the inlet supply pressure Low gas pressure could be an indication of an undersized gas meter and or obstructed gas supply line 6 The correct burner manifold gas pressure is stamped on the rating plate The regulator is preset at the factory and normally requires no further adjustment 7 The gas manifold and control assembly was tested and conform to the safe lighting and oth...

Page 9: ... Relief Valve Hot Water Hot Water Storage Tank Floor Automatic Tempering Valve Cold Water Tempered Water 24 3 Pressure relief valve lever must be tripped at least once a year to insure that waterways are clean When manually operating lever water will discharge through drain line Precautions must be taken to avoid contact with hot water and water damage 4 The weight of all water and gas piping shou...

Page 10: ...nections or other restrictive fittings in heater to tank loop 2 The Model IW heater is designed for use in a system without a hot water storage tank The hot water supply line to usage point must have a return leg to the heater see Figure13 14 and 15 A built in circulating pump and internal heat exchanger bypass maintains the heater in a standby condition It also maintains the temperature at the co...

Page 11: ...ck Valve Throttling Valve Hot Water To Bldg Conventional Tank To Drain To Drain To Drain Pump PW Series VW Series Optional Cold Water Supply When Adequate Tank Opening Not Available Service Valves Hot Water Return From Bldg Cold Water Bldg Loop Circ Pump Hot Water To Bldg Conventional Tank Drain Hot Water Storage Tank 24 Min Service Valves To Drain To Drain Pump PW Series VW Series ...

Page 12: ...tion in the building hot water piping system Cold Water Supply Return Loop Pump see note 2 Check Valve To Drain Conventional Tank To Drain To Drain Recommended Increasing One Pipe Size From C W Connection To Tanks Optional Cold Water Supply When Adequate Tank Opening Not Available Service Valves Pressure Relief Valve Service Valve Hot Water Return From Building Hot Water To Building Service Valve ...

Page 13: ...2 Cold Water Supply Building Loop To Building Service Connections Building Loop Circulator See Note 3 Building Loop To Minimum Pipe Size 1 Thru 850 1 1 4 1010 Thru 1825 Service Valves For Heater Isolation Available In Stage Or Modulated Firing Model IW Water Heater This Seqment Of Piping Must Be Same Size As Water Heater Connection Service Valves For Heater Isolation To Drain To Drain Gas Supply F...

Page 14: ...mp and damage the heater through lack of water circulation If for any reason the water supply is turned off temporarily to service a piece of equipment the manual gas valve on the Model IW should be closed until the water pressure has been restored and the lines bled of accumulated air If the heater fails to fire when it is turned back on it may be airlocked To eliminate the airlock open the press...

Page 15: ...proven to be lit Whenever the pilot flame is interrupted the main gas valve closes within 8 10 of a second b Electronically Supervised Standing Pilot System System 16 When pilot flame fails the ignition control module responds in less than 0 8 seconds and provides 100 safety shutdown 2 Operating Controls a Electrically Operating Controls Single two stage four stage or modulating aquastats are prov...

Page 16: ...e in Return Line from Building Loop D Tempering Valve E Venturi Suction Tee H Throttling Valves in Building Loop Returns I Circulating Pump for 180 Building Loop J Circulating Pump for 140 Building Loop K Service Valves to isolate Heater and Pump for Service With Horizontal Tank With Vertical Tank Cold Water 180 Water To Bldg Conventional Tank To Drain 24 Min To Drain Pump PPW Series PVW Series H ...

Page 17: ...a deposit of silt on the bottom Therefore it is important to extend the pump suction pipe in the tank to a position near the top Pipe the return from the heater to the bottom of the tank 4 If the tank is glass lined it should be equipped with a suitable magnesium anode It is good practice to replace the anode when it is approximately 50 used The factory warranty on a glass lined tank will be void ...

Page 18: ...ating of water occurs 4 Flow Switch Standard on all models Models VW and PW the switch is mounted in the outlet tee connection Model IW the switch is mounted directly in the header outlet The flow switch shuts down all burners in case of low water condition or pump failure 5 Low Water Cut Off The low water cut off automatically shuts off heater whenever water level drops below probe Located at hea...

Page 19: ...ers can be achieved by slowly opening the main manual valve The result should be a smooth lighting of the main burners Hi Limit Checkout After running the heater for a long enough period bring the water temperature within the range of the hi limit and slowly back off the high limit setting until the heater shuts off The main burners should reignite when the hi limit is reset and turned back up to ...

Page 20: ...ion and is a sign of combustion air and or venting problems As soon as any fouling is observed the cause of the fouling should be corrected see Section 5 Troubleshooting Guide The heat b For heaters with the temperature controller bulb at the inlet set the high limit 40 to 50 F above temperature controller setting c If the temperature control sensing bulb is in the heater outlet set the high limit...

Page 21: ...sembly is free of debris d Reassemble in reverse order Be sure the heat exchanger baffles are replaced 8 The gas and electric controls installed on heaters are engineered for both dependable operation and long life but the safety of this equipment completely depends on their proper functioning It is strongly recommended that the basic items be checked by a competent serviceman every year and repla...

Page 22: ...r wired into the pump circuit so that the heater cannot fire unless the pump is running 2 Check to see that all valves in system are open to be sure that water can circulate through the heater and the system 3 If the system has automatic water valves 2 way or 3 way that can cut off the water flow through the heater check to see that they are equipped with end switches which shut the heater down wh...

Page 23: ...ck 2 adequate height of stack above roof 3 equipment exhausting air from inside of building and 4 proper installation of draft diverter D Gas pressure to burners is D Check gas pressure with excessive nanometer and adjust with heater firing at full rate E Heater not fitted for the fuel being E See nameplate for correct fuel supplied F Heater installed at high altitude F Installations at altitudes ...

Page 24: ...National Combustion Company Inc 104 07 180th Street Jamaica NY 11433 718 291 8400 FAX 718 291 6870 Litho in U S A 0610 H2107400A ...

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