4 common vent test, 4 - gas supply and piping – LAARS NeoTherm NTV (Sizes 150–850 MBTU/h) - Install and Operating Manual User Manual
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N
eo
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herm
Boilers and Water heaters
Section 4 -
GAS SUPPLY AND PIPING
Gas piping should be supported by suitable hangers or floor
stands, not the appliance.
Review the following instructions before proceeding with the
installation.
1.
Verify that the appliance is fitted for the proper type of
gas by checking the rating plate. NeoTherm will function
properly without the use of high altitude modification at
elevations up to 10,000 feet (3050 m).
2.
The maximum inlet gas pressure must not exceed 13”
W.C. (3.2kPa). The minimum inlet gas pressure is 4”
W.C. (1.0kPa).
3.
Refer to Tables 6a, 6b, 6c and 6d to size the piping.
4.
Run gas supply line in accordance with all applicable
codes.
5.
Locate and install manual shutoff valves in accordance
with state and local requirements.
6.
A sediment trap must be provided upstream of the gas
controls.
7.
All threaded joints should be coated with piping
compound resistant to action of liquefied petroleum gas.
8.
The appliance and its individual shutoff valve must be
disconnected from the gas supply piping during any
pressure testing of that system at test pressures in excess
of 1/2 PSIG (3.45kPa).
9.
The unit must be isolated from the gas supply system by
closing its individual manual shutoff valve during any
pressure testing of the gas supply piping system at test
pressures equal to or less than 1/2 PSIG (3.45kPa).
10. The appliance and its gas connection must be leak tested
before placing it in operation.
11. Purge all air from gas lines.
WARNING:
Open flame can cause gas to ignite and result in
property damage, severe injury, or loss of life.
NOTE: The NeoTherm appliance and all other gas ap-
pliances sharing the gas supply line must be firing at
maximum capacity to properly measure the inlet supply
pressure. The pressure can be measured at the supply
pressure port on the gas valve. Low gas pressure could
be an indication of an undersized gas meter, undersized
gas supply lines and/or an obstructed gas supply line.
Some NeoTherm units are equipped with low and high
gas pressure switches that are integrally vent limited.
These types of devices do not require venting to atmo-
sphere.
3.4 Common Vent Test
NOTE: This section does not describe a method for
common venting NeoTherm units. It describes what
must be done when a unit is removed from a common
vent system. NeoTherm units require special vent
systems and fans for common vent. Contact the factory
if you have questions about common venting NeoTherm
units.
When an existing boiler is removed from a common venting
system, the common venting system is likely to be too large
for proper venting of the appliances remaining connected to it.
At the time of removal of an existing boiler, the following
steps shall be followed with each appliance remaining
connected to the common venting system placed in operation,
while the other appliances remaining connected to the
common venting system are not in operation.
1. Seal any unused openings in the common venting system.
2. Visually inspect the venting system for proper size and
horizontal pitch and determine there is no blockage or
restriction, leakage, corrosion and other deficiencies
which could cause an unsafe condition.
3. Insofar as it is practical, close all building doors and
windows and all doors between the space in which the
appliances remaining connected to the common venting
system are located and other spaces of the building. Turn
on clothes dryers and any appliance not connected to
the common venting system. Turn on any exhaust fans,
such as range hoods and bathroom exhausts, so they will
operate at maximum speed. Do not operate a summer
exhaust fan. Close fireplace dampers.
4. Place in operation the appliance being inspected. Follow
the lighting instructions. Adjust the thermostat so the
appliance will operate continuously.
5. Test for spillage at the draft hood relief opening after
5 minutes of main burner operation. Use the flame of a
match or candle, or smoke from a cigarette, cigar or pipe.
6. After it has been determined that each appliance
remaining connected to the common venting system
properly vents when tested as outlined above, return
doors, windows, exhaust fans, fireplace dampers and any
other gas burning appliance to their previous conditions
of use.
7. Any improper operation of the common venting system
should be corrected so that the installation conforms to
the National Fuel Gas Code, ANSI Z223.1/NFPA 54 and/
or CSA B149.1, Installation Codes. When resizing any
portion of the common venting system, the common
venting system should be resized to approach the mini-
mum size as determined using the appropriate tables and
guidelines in the National Fuel Gas Code, ANSI Z223.1
NFPA 54 and/or CSA B149.1, Installation Codes.