Protecting The Boiler From Freezing; Maintenance Schedules - Navien NCB-190/060H User's Information Manual

4.6 Protecting the Boiler from
Freezing
CAUTION
Damage due to freezing is not covered by the
Navien limited warranty.
Freezing damage is most likely to occur due
●
to back drafting caused by negative pressure
in the building. This is not a manufacturing
defect, and therefore, Navien will not
warrant any damages due to freezing. The
installer is responsible for ensuring that
there is sufficient make-up air to avoid such
a situation and the owner is responsible for
ensuring that protection against freezing is
maintained.
To avoid freezing issues, we strongly
●
recommend the use of a direct vent exhaust
and intake system. Your installer should
ensure that the exhaust vent pipe and the
air intake pipe are both connected directly
from the collars on the top of the boiler to the
outdoors. This type of vent system minimizes
air movement within the boiler.
This boiler has an optional recirculation mode
●
that is used for freeze protection. This mode
should prevent the boiler from freezing, even
if the intake air duct is not vented directly.
The boiler is designed for indoor installation
●
only.
To ensure that the boiler does not freeze, follow
these guidelines:
Do not unplug the power supply cord, except
●
for routine maintenance. The boiler has a freeze
protection function that requires electricity. The
freeze protection function will operate regardless
of whether or not the power is turned on or off, as
long as the electric supply is still connected.
Do not close the gas valve, except for routine
●
maintenance, as this will limit additional freeze
protection.
If the boiler will not be used for an extended
●
period, drain the boiler.
If the power or gas supplies must be
disconnected for an extended period, drain the
boiler. Freezing damage may occur if there is
water remained in the boiler in cold weather.
18 Maintaining the Boiler
If hot water will not flow and you
Note
●
suspect that the boiler is frozen,
contact an authorized technician or
licensed professional.
This boiler requires very little
●
maintenance, however a qualified
technician should inspect the boiler at
the beginning of every heating season
and/or when there is a problem.
CAUTION
If the unit will not be used immediately, close off
all gas and water shutoff valves, drain all of the
water out of the unit and the plumbing system
to prevent the unit and system from freezing,
and bleed the gas out of the gas line.

4.7 Maintenance Schedules

Regular maintenance is required to operate the
boiler safely. Refer to the maintenance schedules
below for proper maintenance of the boiler.
Owner maintenance
Check the boiler area
●
is free of combustible/
flammable materials and air
contaminants.
Daily
Check the pressure/
●
temperature gauge for
signs of higher than normal
pressure.
Visually inspect the vent
●
piping for signs of leakage
and blockage.
Monthly Visually inspect the burner
●
flames.
Inspect the condensate trap
●
and the PVC fittings.
Test the LWCO for proper
●
Periodically
operation.
Inspect boiler piping (gas and
●
water) for leaks.
Every 6
months
Test to make sure the relief
●
valve is operating normally.
Shut boiler down (unless
●
Non-heating
boiler is used for domestic hot
season
water).