Protecting The Water Heater From Freezing - Navien NPE-180A2 Mode D'emploi

4.6 Protecting the Water Heater
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 water heater
to the outdoors. This type of vent system
minimizes air movement within the water
heater.
This water heater has an optional recirculation
mode that is used for freeze protection. This
mode should prevent the water heater from
freezing, even if the intake air duct is not
vented directly.
The water heater is designed for indoor or
outdoor installation. However, it should not
be installed outdoors in areas that are prone
to freezing temperatures.
To ensure that the water heater does not freeze,
follow these guidelines:
Do not unplug the power supply cord, except
for routine maintenance. The water heater
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 ("A2" model only).
If the power or gas supplies must be
disconnected for an extended period, drain the
water heater. Freezing damage may occur if there
is a loss of power or an interruption in the gas
supply to the water heater.
If the water heater will not be used for an
extended period, drain the water heater.
If hot water will not flow and you suspect that the
water heater is frozen, follow these steps:
1. Press the Power button on the front panel to
turn off the water heater.
2. Close the gas valve.
Gas
Valve
3. Open the hot water faucet that is closest to the
water heater.
4. Use a hair dryer or a portable electric heater to
heat up both the primary and secondary Heat
Exchangers.
5. Check every few minutes to see if water is
running at the open faucet.
6. When the water starts flowing again, check the
water heater and piping for leaks. If you detect
any leaks or the water heater is not operating
properly, contact an authorized technician or
licensed professional.
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.
Maintaining the Water Heater
Opened
Closed
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