Water heater manual document 2105 installation and operating instructions for natco fire coil mighty therm models vw, pw and iw volume water heaters sizes 500-1825 mighty therm for your safety do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other app...
Contents section 1. General information page 1a. Introduction ...................................................... 3 1b. Heater identification ......................................... 3 1c. Flow requirements .......................................... 4 1d. Water chemistry ...........................
Section 1 general information 1a. Introduction this manual provides information for the installation and operation of natco volume water heaters. It is strongly recommended that all application and installation procedures be reviewed completely before proceeding with the installation. Consult the na...
Section 2 installation 2a. Heater placement the heater must be placed to provide specific clearances on all sides for maintenance and inspection. There must also be minimum distances maintained from combustible surfaces. These clearances also apply to non-combustible materials because the heater req...
Figure 5 – installation on concrete blocks or tile figure 2 – typical heater installation with base for combustible floors, example a figure 3 – typical heater installation with base for combustible floors, example b figure 4 – typical heater installation with base for combustible floors, example c ...
12 inches of the ceiling, and the other within 12 inches of the floor. Each opening should have a minimum free area of one square inch per 4,000 btuh input of the total input rating of all appliances in the enclosed area. See table ii for recommended air supply for each model. An improperly ventilat...
7 figure 7 – incorrect outdoor installation window or grill indoor room wrong highest point of the building with an approved vent cap. The venting system should be installed according to the latest edition of ansi z223.1 and/or, in canada, can1-b149 requirement and any local codes having jurisdictio...
Attached. 2. Use the figures in table iii to provide adequate gas piping from the gas meter to the heater. Table iii. Gas piping sizes distance from gas meter or last stage regulator model 0-100' 100-200' 200-300' 500 1-1/2" 2" 2" 600 1-1/2" 2" 2-1/2" 715 2" 2" 2-1/2" 850 2" 2-1/2" 2-1/2" 1010 2" 2-...
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...
Leak. The following suggestions may solve the problem: 1. Replace the installed water pressure reducing valve with a suitable valve having a back flow port. These valves have a back flow port which allows water to flow backwards when the pressure in the system exceeds the pressure in the mains. 2. I...
11 figure 11 – hot water supply system (model vw & pw) notes: heavy line indicates heater to tank circulating loop. With horizontal tank with vertical tank cold water bldg. Loop circ. Pump check valve throttling valve hot water to bldg. Conventional tank to drain to drain to drain pump pw series vw ...
12 figure 13 – split system piping diagram, model iw figure 12 –hot water supply system using model pw with dual tanks, building loop return and circulating pump notes: 1. Heavy line indicates heater to tank circulating loop. 2. When a very large volume of water is circulated in the building loop wi...
13 figure 15 – single installation piping diagram, model iw figure 14 – dual installation piping diagram, model iw notes: 1. All water connections 2" n.P.T. Models. 2. Drain valve per asme requirements. 3. A loop circulator is required to maintain forced circulation in the building hot water piping ...
5. Pump sizing: a suitable pump must be field- provided for circulation of water between model vw heaters and the storage tank. This pump must be sized to avoid excessive temperature rise and to provide correct flow for water hardness conditions. Specifications in table iv include allowance for 30 f...
2k. Two-temperature system see figure 16 and figure 17 for piping schematic. This system is designed to maintain the tempered water circulating loop at the desired temperature during idle periods as well as when there is a demand for hot water. It is recommended for general purpose water supply incl...
15 figure 16 – two-temperature hot water supply system (model vw or pw) legend b – check valve in hot water supply to tempering valve c – check valve in return line from building loop d – tempering valve e – venturi (suction) tee h – throttling valves in building loop returns i – circulating pump fo...
C d b k j c h c h j 180 ° f water to bldg. Conventional tank 140 ° f water to bldg. To drain to drain cold water to drain pump pw series vw series 140 ° f water return from bldg. 180 ° f water return from bldg. Cold water pump pw series vw series 16 figure 17 – two-temperature hot water supply syste...
Dial no. 1 2 3 4 5 6 7 8 9+ temp °f 120 128 135 143 150 158 165 173 180+ 18 figure 20 – pilot burners (i.I.D.) table v – modu-snap temperature settings figure 19 – control components manual reset high limit flow switch t.L. Part # e159 t.L. Part # e130 gasl modulating valve low water cutoff t.L. Par...
19 cutoff, etc.) pilot(s) can be lit following the procedure located on the heater rating plate. 3. Once the pilot(s) is lit and has been established for five minutes, the flame failure response time should be checked as follows: systems 4 and 9 - (intermittent ignition), natural gas only: with this...
20 figure 22 – pilot safety relay figure 23 – main burner flame pattern section 4 maintenance 1. Lubricate the water circulating pump (see instructions found on the pump). 2. If a strainer is employed in a pressure reducing valve or in piping, clean it every six (6) months. 3. At start-up and every ...
21 exchanger can be checked by locating a mirror under the burners with a flashlight. An alternate method is to remove the venting and top panel as necessary to inspect from above. Also check the vent system for defects at this time. A. If cleaning is required, shut off all electrical and gas supply...
22 i. Heater will not fire possible cause what to do a. Electric power is off a. Check to see that main power switch is "on." use testing device to trace power to heater junction box. B. Operating or safety control has b. Turn off power. Use continuity opened circuit to electric gas valve. Across te...
23 iv. Soot in flueways or in tubes, or noxious fumes indicative of bad combustion possible cause what to do a. Combustion air supply to heater a. Check air supply opening. Look room is inadequate. For debris in screen or louvre which covers combustion air opening, or for material blocking the openi...
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