Gas Supply And Gas Pipe Sizing; General; Gas Connections; Measuring Inlet Gas Pressure - Takagi T-KJr2-IN / 110 Installation Manual And Owner's Manual

Gas supply and gas pipe sizing

General

• Check that the type of gas matches the
rating plate first.
• Ensure that any and all gas regulators
used are operating properly and
providing gas pressures within the
specified range shown below. Excess
gas inlet pressure may cause serious
accidents.
• Conversion of this unit from natural gas
to propane or vice versa will void all
WARNING
warranty . Contact your local distributor
to get the correct unit for your gas type .
The manufacturer is not liable for any
property and/or personal damage
resulting from gas conversions .
• The minimum and maximum inlet gas pressures are:
Gas type
Natural Gas Min . 5 .0" W .C . – Max . 10 .5" W .C .
Propane Gas Min . 8 .0" W .C . – Max . 14 .0" W .C .
• Inlet gas pressures that fall outside the range of values
listed above may adversely affect the performance of the
water heater . These pressures are measured when the
water heater is in full operation .
• Inlet gas pressure must not exceed the above maximum
values; gas pressure above the specified range will
cause dangerous operating conditions and damage to
the unit .
• Until testing of the main gas line supply pressure is
completed, ensure the gas line to the water heater is
disconnected to avoid any damage to the water heater .

Gas Connections

1 . Install a manual gas shutoff valve between the water
heater and the gas supply line .
2 . When the gas connections are completed, it is necessary
to perform a gas leak test (see below) either by applying
soapy water to all gas fittings and observing for bubbles
or by using a gas leak detection device .
• The water heater and its individual shutoff valve
must be disconnected from the gas supply piping
system during any pressure testing of that system at
test pressures in excess of 1/2 psi (3 .5 kPa) .
• The water heater must be isolated from the gas
supply piping 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 psi (3 .5kPa) .
3 . Always purge the gas line of any debris, inert gas* and/
or water before connecting to the gas inlet .
* Inert gas may be left in the line from pressure testing .
Note: Size the gas pipe appropriately to supply the
necessary volume of gas required for the water heater using
CSA B149.1 Natural Gas and propane Installation Code
or local codes . Otherwise, flow capabilities and output
temperatures may be limited . The installation shall comply
with CSA B149.1 Natural Gas and propane Installation
Code.
Inlet gas pressure

Measuring Inlet Gas Pressure

1 . Turn off all electric power to the water
heater if service is to be performed .
2 . Turn the manual gas valve located on
the outside of the unit clockwise to the off
position .
The water heater cannot perform properly without sufficient
inlet gas pressure . Below are instructions on how to check
the inlet gas pressure . THIS IS ONLY TO BE DONE BY A
LICENSED PROFESSIONAL .
1 . Shut off the manual gas valve on the supply gas line .
2 . Remove the screw for the pressure port located on the
gas inlet of the water heater shown in the diagram below .
3 . Connect the manometer to the pressure port .
4 . Re-open the manual gas valve . Check to see that there
are no gas leaks . Take a reading of the gas pressure .
Open some of the fixtures that use the highest flow rate
to turn on the water heater .
5 . Check the inlet gas pressure . Take another reading .
When the water heater is on maximum burn, the manom-
eter should read from 5 .0" to 10 .5" W .C . for Natural gas
or from 8 .0" to 14 .0" W .C . for Propane . Verify drop meets
code .

Water Connections

• Do not use this water heater if any
part has been submersed under water .
Immediately call a licensed professional
to inspect the water heater to replace any
damaged parts .
• Do not reverse the hot outlet and cold
inlet connections to the water heater .
CAUTION
This will not properly activate the water
heater .
All pipes, pipe fittings, valves and other components,
including soldering materials, must be suitable for potable
water systems .
1 . A manual shutoff valve must be installed on the cold
water inlet to the water heater between the main water
supply line and the water heater .
Pressure
port
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