John Wood Takagi - 110-310-510 - Manual (Page 15)

15
Gas supply and gas pipe sizing
General
WARNING
Check that the type of gas matches
the rating plate first.
Ensure that any and all gas regula-
tors 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 vise versa will void all
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. •
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The minimum and maximum inlet gas pressures are:
Gas type Inlet gas pressure
Natural Gas Min. 5.0” WC – Max. 10.5” WC
Propane Gas Min. 8.0” WC – Max. 14.0” WC
Gas pressure above this specified range for the water
heater and/or insufficient gas volume will adversely affect
performance. 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 com-
pleted, ensure the gas line to the water heater is discon-
nected to avoid any damage to the water heater.
Gas Connections
1. Install a manual gas shut-off 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 sup-
ply 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 and/or water
before connecting to the gas inlet.
Note: Size the gas pipe appropriately to supply the neces-
sary 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 tem-
peratures may be limited.
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Measuring Inlet Gas Pressure
Turn off all electric power to the water
heater if service is to be performed.
Turn the manual gas valve located on
the outside of the unit clockwise 3 to the
off position. 1.
2.
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.
Shut off the manual gas valve on the supply gas line.
Remove the screw for the pressure port located on
the gas inlet of the water heater shown in the diagram
below.
Connect the manometer to the pressure port.
Re-open the manual gas valve. Check to see that there
are no gas leaks. Open some of the fixtures that use the
highest flow rate to turn on the water heater.
Check the inlet gas pressure. When the water heater is
on maximum burn, the manometer should read from 5.0”
to 10.5” WC for Natural gas, from 8.0” to 14.0” WC for
Propane.
Pressure
port
Water Connections
CAUTION
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.
This will not properly activate the water
heater. •
•
All pipes, pipe fittings, valves and other components, includ-
ing soldering materials, must be suitable for potable water
systems.
1. A manual shut off valve must be installed on the cold
water inlet to the water heater between the main water
supply line and the water heater.
1.
2.
3.
4.
5.