4. SERVICING PROCEDURES
SEQUENCE OF OPERATION
INTERMITTENT IGNITION DEVICE (IID)
Heaters equipped with the IID system will automatically
light the pilot burner first and then the main burner, each
time there is a call for heat from the tankstat. Whenever
the tankstat calling for heat, the circulator supplied with
the heater, will be energized and should be running. The
ignition control module will also be energized to initiate
the pilot ignition by opening the first main valve (pilot). At
the same time, the electronic spark generator in the
module produces a high voltage spark pulse output that
lights the pilot burner. If the pilot burner does not light,
the module will not energize the second main valve and
the burners will not light. Ignition spark continues only
until the timed trial for ignition period ends. Then, the
module goes into safety shutdown or lockout. Lockout
de-energizes the first main valve operator and closes the
first main (pilot) valve in the gas control, stopping pilot
gas flow. The ignition control system must be reset by
setting the tankstat below water temperature for one
minute or by turning off power to the module for one
minute. When the pilot flame is established, flame
rectification circuit is completed between the sensor and
burner ground. The flame sensing circuit in the module
detects the flame current, shuts off the spark generator
and energizes the second main valve operator which
opens the second main valve. This allows gas to flow to
the burners where it is ignited by the pilot burner flame.
When the tankstat is satisfied, the valve operators are
de-energized shutting off the pilot and main burners, and
also the circulator.
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START-UP PROCEDURES
SECTION 1
.
Filling the System
Fill system with water. Purge all air from the system
using purge valve sequence. After system is purged of
air, lower system pressure.
Flush system before putting into operation to assure
that foreign material does not damage pump seals.
SECTION 2
.
Checking the Circulator
Before lighting the heater and after system is filled,
make sure that circulator is operating properly. Manual
gas valve should be off.
NOTE: Circulator motor supplied with the heater does not
require lubrication.
SECTION 3. Lighting the Heater
For your safety read carefully before proceeding to light
the heater.
CAUTION:
Liquefied petroleum gas is heavier than air
and sinks to the ground. Exercise extreme care in
lighting heater in confined areas.
For Standing Pilot Models
WARNING: If you do not follow these instructions ex-
actly, a fire or explosion may result causing property
damage, personal injury or loss of life.
