A.O. Smith Hot Water Generator 技术手册
11
operatIon
General safety
Never operate the heating coil without being certain the hot water
generator is filled with water, and a temperature and pressure relief
valve is installed in the relief valve opening on top the heater.
Additional safety features such as temperature controlled solenoid
valves are available as options.
FIllINg the tANk:
1. Valve off the heating medium.
2. Close the hot water generator drain valve.
3. Open a nearby hot water point of use to allow the air in the system
to escape.
4. Fully open the cold water inlet valve, filling the unit and piping.
5. Shut off the hot water at point of use as water starts to flow
from the opening. Leave the cold water inlet valve fully open.
The hot water generator is now ready for START UP and
TEMPERATURE REGULATION if being placed in operation for
the first time.
InItIal start-up
Prior to initial start -up all steam and condensate lines or boiler
water circulation lines should be blown down or flushed out to
prevent any dirt, weld slag, solder balls, etc, from entering the
heating coil, temperature control valves or other apparatus
connected to the heater.
Upon initial start-up the main steam globe or gate valve should be
cracked slightly to allow the heating surface to come up to operating
temperature. If cracking noises occur in the heating element on start-
up, do not be alarmed. This cracking noise should stop when the
heating surface gets warm.
Do not fully open a steam hand valve on initial start-up, as this may
cause internal damage to the heat exchanger.
Once the heater is in operation and all valves are adjusted, water
temperature control should be done by means of the self-activated
temperature regulator.
teMperature reGulatIon
It is recommended that lower water temperatures be used to avoid
the risk of scalding. It is further recommended, in all cases, that the
water temperature be set for the lowest temperature which satisfies
your hot water needs. This will also provide the most energy efficient
operation of the water heater.
Short repeated heating cycles caused by small hot water uses can
cause temperatures at the point of use to exceed the thermostat setting
by up to 20°F (11°C). If you experience this type of use you should
consider using lower temperature settings to reduce scald hazards.
HOT WATER CAN SCALD: Water heaters are intended to produce hot
water. Water heated to a temperature which will satisfy space heating,
clothes washing, dish washing, and other sanitizing needs can scald
and permanently injure you upon contact. Some people are more likely
to be permanently injured by hot water than others. These include
the elderly, children, the infirm, or physically/mentally handicapped. If
anyone using hot water from this heater fits into one of these groups
or if there is a local code or state law requiring a certain temperature
water at the hot water tap, then you must take special precautions. In
addition to using the lowest possible temperature setting that satisfies
your hot water needs, a means such as a mixing valve, should be
used at the hot water taps used by these people or at the water heater.
Mixing valves are available at plumbing supply or hardware stores.
Follow manufacturer’s instructions for installation of the valves.
Water Temperature
Time to Produce 2nd & 3rd
Degree Burns on Adult Skin
180°F (82°C)
170°F (77°C)
160°F (71°C)
150°F (65°C)
140°F (60°C)
130°F (54°C)
120°F (49°C)
170°F (77°C)
160°F (71°C)
150°F (65°C)
140°F (60°C)
130°F (54°C)
120°F (49°C)
Nearly Instantaneous
Nearly Instantaneous
Nearly Instantaneous
About 1/2 Second
About 1 - 1/2 Seconds
Less than 5 Seconds
About 30 Seconds
More than 5 Minutes
Never allow small children to use a hot water tap, or to draw their own
bath water. Never leave a child or handicapped person unattended in
a bathtub or shower.
Refer to the vendor manual(s) attached for information on electric
temperature controls and valve actuators.
draInInG the tank
The water heater must be drained if it is to be shut down and exposed
to freezing temperatures. Maintenance and service procedures may
also require draining the hot water generator.
1. Turn off power to the water heater.
2. Turn the valve off to the heating medium (steam or hot water).
3. Close the cold water inlet valve to heater.
4. Open a nearby hot water faucet to vent the system.
5. Open drain valve. Danger: Water temperature over 125°F (52°C)
can cause severe burns instantly resulting in severe injury or death.
Take precautions to prevent contact with the water being drained.
6. If the hot water generator is being drained for an extended shutdown,
it is suggested the drain valve be left open during this period.
Follow FILLING instructions when restoring hot water service.