Takagi T-H3M-IN/OS - Manual (Page 20)

20
Page
Installation
Installation Manual
GAS SUPPLY AND GAS PIPE SIZING
-General-
• The minimum and maximum inlet gas pressures are:
• 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 water heater
• 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 The gas supply
line shall be checked for leaks using code approved methods
2 When the gas connections are completed, it is necessary to perform a gas leak test 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
(35 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 (35 kPa)
3 Always purge the gas line of any debris and/or water before connecting to the gas inlet
Size the gas pipe appropriately to supply the necessary volume of gas required
for the water heater using ANSI Z2231/NFPA 54 in the USA or CAN/CSA B1491 in
Canada or local codes Otherwise, flow capabilities and output temperatures will
be limited
NOTICE
Gas type Inlet gas pressure
Natural Gas Min 50” WC (124 kPa) – Max 105” WC (261 kPa)
Propane Min 80” WC (199 kPa) – Max 140” WC (348 kPa)
• 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 water heater from natural gas to propane or vice 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
CAUTION