25
Installing the System Piping
CAUTION
●
All field supplied pressure relief valves must
be ASME certified.
●
To avoid potential property damage or
personal injury, check the pressure relief
valve at least once every three years by
manually operating the valve to ensure
proper operation.
●
Before manually operating the valve, check
the discharge line and make sure that the
hot discharge water will not cause personal
injury or property damage. Contact with
the discharged water may result in severe
personal injury.
3.1.3 Space Heating System Piping
When connecting the space heating system, follow
these guidelines:
●
Tighten the connection valves with care to avoid
damage.
●
After installing the boiler, clean the strainer for
space heating return. Then, test the boiler for
proper space heating flow and inspect for leaks.
Instruct the boiler owner that the strainer must
be cleaned periodically to maintain proper space
heating water flow.
The Navien manifold system allows for easy
separation of the Boiler-Primary loop from the
System-Secondary loop(s). Refer to the following
illustration for a typical water piping example with a
Navien manifold system.
Space
Heating
Supply
Space
Heating
Return
●
After filling and pressurizing the system, test
the relief valve operation by lifting the lever. If
the valve fails to operate correctly, immediately
replace the relief valve.
●
Ensure that the discharge line provides complete
and unobstructed drainage. Do not install a
reducing coupling or other restrictions on the
discharge line.
If the relief valve discharges periodically, this may be
caused by thermal expansion when the expansion
tank is full or undersized. Do not plug the relief
valve.
Refer to the following illustration and install a
pressure relief valve to the pressure relief valve
adapter located on the top corner of the NFC-H
boiler. Conbraco Watts M330-M1 pressure relief
valve (
3
/
4
in, HV, Max 30 psi) is provided with the
boiler.
Pressure
Relief Valve
Note
Depending on the installation
conditions, pressure relief valves (not
included and for separate purchase) of
up to 80 psi can be used.
WARNING
To avoid water damage or scalding, direct the
discharge line to a safe place for disposal.
Summary of Contents for NFC-250/175H
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