Takagi T-M50 - Manual (Page 16)

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Size the gas pipe appropriately to supply the necessary volume of gas required for the
water heater using ANSI233.1/NFPA 54 in the USA or CAN/CSA B149.1 in Canada or
local codes. Otherwise, flow capabilities and output temperatures will be limited.
GAS SUPPLY AND GAS PIPE SIZING
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.
WARNING: 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.
*Check that the type of gas matches the rating plate first.
 The minimum and maximum inlet gas pressures are:
Gas type Inlet gas pressure
Natural Gas Min. 5.0” WC – Max. 10.5” WC
Propane 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. Ensure that any and all
gas regulators used are operating properly and are providing gas pressures within the specified
range shown above.
 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 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 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 and/or water before connecting to the gas inlet.
TO TURN OFF GAS TO APPLIANCE
NOTICE