Navien LST-58K, Instruction Manual

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Precautions for piping installation
Precaution for the piping installation for the combi boiler for heating
and hot water supply / the dedicated boiler for heating
L S T- 58K
Open piping system
Be sure to comply with the instructions presented in the “Considerations in common”.
Be sure to install the air vent valve in the distributor.
The return distributor shall be installed below the heating inlet on the boiler.
The pressure release pipe shall be installed to exceed 25A.
Never supply the water with a pressure higher than the maximum allowable working
pressure of the boiler specified on the name plate, nor connect the water pipe directly
for the piping.
The reverse flow of the heating water into the expansion tank, while operating or
stopping the circulation pump, results from too much air in the pipe. (Open the valve
in the distributor one by one and remove the air from the pipe, while operating the
circulation pump.)
The expansion tank shall be installed at least 1.5m above the heat dissipation surface
in case of the upward type, and at least 1.5m above the top of the boiler in case of the
downward type.
The piping installation shall be performed not to mix the heating water and the hot
water.
Closed piping system
Be sure to comply with the instructions presented in the “Considerations in common”.
Be sure to install the strainer, the depressurizing valve, the check valve, the safety valve,
and the enclosed expansion tank, in order to directly connect the boiler to the water
pipe.
Be sure to install the depressurizing valve and the check valve in the water supply pipe.
Install the air vent on top of the heat dissipation surface to facilitate air vent.
Be sure to install the strainer in the water supply pipe, in order to prevent metal and
foreign objects from flowing into the water supply pipe.
Be sure to install the safety valve.
Be sure to install the enclosed expansion tank with an appropriate capacity.