Takagi T-H3M-IN/OS - Manual (Page 22)

22
Page
Installation
Installation Manual
-Measuring inlet gas pressure-
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
WATER CONNECTIONS
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
2. In addition, a manual shutoff valve is also recommended on the hot water outlet of the water heater
If the water heater is installed within, or subjected to, a closed loop water system, a thermal expansion
tank or code approved device to handle thermal expansion must be installed We recommend isolation
valve sets with hose bibs for serviceability such as flushing See maintenance and service section
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 water heater clockwise
to the off position
• 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
CAUTION
1 Shut off the manual gas valve on the gas supply line
2 Remove the screw for the pressure port located on the
gas inlet of the water heater shown in the diagram on
the right
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 and minimum
burn, the manometer should read from 50” to 105”
WC (124 to 261 kPa) for Natural gas, or from 80” to
140” WC (199 to 348 kPa) for Propane Verify that the
pressure drop is acceptable
3. Before installing the water heater, flush
the water line to remove all debris, and
after installation is complete, purge
the air from the line Failure to do so
may cause damage to the heater
4. There is a wire mesh filter within
the cold inlet to trap debris from
entering your heater This will need
to be cleaned periodically to maintain
optimum flow (Refer to p 41)
Cold
inlet
Hot
outlet
Gas inlet
As Close as
Possible
Pressure relief valve
Pressure port