Installing the System Piping 23
When installing pressure relief valve, follow these guidelines:
●
Ensure that the valve’s discharge capacity is equal to or greater
than the maximum pressure rating of the boilers DHW system.
●
Ensure that the maximum BTU/H rating on the pressure relief
valve is equal to or greater than the maximum input BTU/H
rating of the boiler.
●
Direct the discharge piping of the pressure relief valve so
that hot water does not splash on operator, or any nearby
equipment.
●
Attach the discharge line to the pressure relief valve and run the
end of the line to within 6-12 in (150-300 mm) of the floor.
●
Ensure that the discharge line allows for free and complete
drainage without restriction. Do not install a reducing coupling
or other restrictions on the discharge line.
●
If the relief valve discharges periodically, this may be due to
thermal expansion in a closed water supply system. Contact the
water supplier or local plumbing inspector on how to correct the
situation. Do not plug the relief valve.
3.2.3 DHW System Piping
CAUTION
To comply with ASME or CRN requirements, an additional high
temperature limitation device may be needed. Consult your
local code requirements to determine if this device is required.
Refer to the following illustration for a typical DHW piping example
for the boiler.
DHW Supply
Cold Water Supply
When installing the DHW system, follow these guidelines:
●
Use only pipes, fittings, valves, and other components (such as
solder), that are approved for use in potable water systems.
●
Tighten the connection valves with care to avoid damage.
●
Navien recommends using unions and manual shut-off valves
on the cold water inlet and DHW outlet.
●
Keep the hot water piping system as short as possible, to deliver
hot water to the fixtures more quickly.
●
To conserve water and energy, insulate the DHW supply and
DHW recirculation lines (if applicable). Do not cover the drains or
pressure relief valves.
●
After installing the boiler, clean the cold water inlet filter.
Then, test the boiler for proper DHW supply and inspect for
leaks. Instruct the boiler owner that the filter must be cleaned
periodically to maintain proper DHW flow.
3.3 Connecting the Condensate Drain
The Navien NCB boiler creates condensation when it operates.
This condensation has an acidic pH of 3-5. Follow all local codes
and regulations when disposing of condensate from the boiler.
We recommend draining the condensate into a laundry tub,
as the alkali in laundry detergent will neutralize the acid in the
condensate. However, other suitable waste drain locations may be
used according to the local codes.
CAUTION
●
Do not cap or plug the integrated condensate line. If
prevented from draining, condensate can damage the boiler.
●
The condensate line must have a negative slope to drain
properly.
