American Water Heater Commercial Gas ユーザーズマニュアル

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1. Once a month the heater should be flushed.  Open the drain

valve and allow two gallons of water to drain from the heater.
Inlet water valve should remain open to maintain pressure in tank.

2. A cleanout opening is provided for periodic cleaning of the

tank.  Gas must be shut off and heater drained before opening
cleanout.

To clean heater through cleanout opening, proceed as follows:

1. Drain heater.

2. Remove outer cover plate from lower side of heater jacket.

3. Remove six (6) hex head screws securing tank cleanout plate

and remove plate.

4. Remove lime, scale, or sediment using care not to damage

the glass lining.

5. Inspect cleanout plate gasket.

6. Install cleanout plate.  Be sure to draw plate up tight by

tightening screws securely.

7. Replace outer jacket cover plate.

In some water areas the sediment might not be removed by this
method and may result in the water heater making rumbling or
boiling noises.

Before calling your service agent, the following checklist should
be examined to eliminate obvious problems from those requiring
replacement or servicing.
— Check that “main manual gas shutoff valve” is fully open and

that gas service has not been interrupted.

— Check that after following the appliance OPERATING

INSTRUCTIONS, the “Top Knob” of the appliance gas valve is
in “ON” position.

— Check electrical supply to the appliance for possible blown (or

tripped) fusing or power interruption.

— Is the water temperature in tank below the thermostat dial

setting on the appliance thermostat (calling for heat)?

The amount of calcium carbonate (lime) released from water is in
direct proportion to water temperature and usage, see chart.  The
higher the water temperature or water usage, the more lime
deposits are dropped out of the water.  This is the lime scale
which forms in pipes, heaters and on cooking utensils.

Lime accumulation not only reduces the life of the equipment but
also reduces efficiency of the heater and increases fuel
consumption.

The usage of water softening equipment greatly reduces the
hardness of the water.  However, this equipment does not always
remove all of the hardness (lime).  For this reason it is
recommended that a regular schedule for deliming be
maintained.

The time between cleaning will vary from weeks to months
depending upon water conditions and usage.

Hydrochloric base acids are not recommended for use on glass
lined tanks.

Observe handling instructions on label of product being used.

The following practices will ensure longer life and enable the unit
to operate at its designed efficiency: