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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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Page 15

N

eo

T

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.

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