Initial Start-Up; To Start Up System; Gas Manual Valves - Natco VW Installation And Operating Instructions Manual

Volume water heaters sizes 500-1825 vw series/pw series/iw series
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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 system pilots are automatically lit
when the operating controls call for heat. If the pilot
flame fails for any reason, the main valve is shut off
within one second and the pilot spark ignition is
initiated until the pilot flame has been reestablished.
This sequence should be checked by turning off the
manual pilot gas valve, and, at the same time,
monitoring the audible sparking at the pilot burner and
signal interruption to the main valve.
CAUTION: Propane gas is heavier than air and sinks
to the ground. Exercise extreme care in lighting the
heater when so equipped.
System 16 - (Electronically supervised standing pilot
system), standard on propane gas: Extinguish the
pilot flame by placing the manual pilot valve in the
closed position, and at the same time, begin recording
the time it takes for the output signal from the
electronic ignition control to be interrupted. The signal
inter- ruption can be detected either with a test light or
a voltmeter. The response time should never exceed
one second.
4. With the pilots lit, initial activation of the main
burners 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 its
original setting. The heater should now run until it
shuts off automatically on operating aquastat.
3C.

To Start Up System:

1. Start Up Boiler
Be certain system pump is running, then
proceed as follows:
a. Turn off main electrical switch.
b. Turn off all manual gas valves and wait five
minutes. (Figure 21)
ON
ON POSITION
ON
Figure 21 – Gas Manual Valves
c. Set operating control to lowest setting.
d. Slowly turn manual gas valve to "ON".
e. Reset all safety valve switches (manual reset
high limit and low water cut off).
f.
Open manual pilot valve. Turn on main
electrical switch.
g. Set temperature controller to desired
temperature. Pilot will light automatically to
ignite main burners whenever the aquastat
calls for heat.
For standing pilot system, press on pilot relay
knob, see Figure 22, light pilot and keep relay
knob depressed for one minute then release.
Once the pilot is lit, the power is supplied through
the aquastat to the main gas valve.
2. To set the temperature and high-limit
controls:
a. Set the temperature controller at the system
design temperature.
19
Pilot Valve
ON
Main Gas Valve
Pilot Valve
OFF POSITION
Main Gas Valve

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