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Finned copper tube gas boilers & water heaters – Boiler Manual
28
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CONTROL DESCRIPTION
Low Water Cutoff
If the boiler is to be installed above radiation or if required by other codes
or regulations, install a low water cutoff in appropriate piping. Wire the switch
to the “Interlock” contacts as illustrated on “Field Wiring” schematic. Ensure
that the low water cutoff device(s) will funtion properly.
Operating Control
Th e preferred control sett ing for potable hot water is
130°F
,
54°C
.
Th e operating control should be set to the lowest sett ing that will
satisfy the consumer’s needs.
Sett ing the thermostat or operation control too high
can result in scalding resulting in severe personal injury!
High Limit (Aquastat)
Th e high limit is located in the top control area of the boiler/water
heater. A remote capillary bulb is run to a well on the outlet side
of the supply header. Th e high limit can be reset by depressing
the red butt on.
Th e water heater high limit should be set a minimum of
20°F
,
11°C
higher than the operating control. Refer to the HOT WATER
SUPPLY section for the proper supply water temperature.
Flow Switch
A fl ow switch is provided in the water outlet piping to prevent the
boiler/water heater from fi ring without adequate water fl ow through
the heat exchanger.
DIAGNOSTICS
Th e Futera III has a display that indicates the sequence of
operation. Th e display will also list faults should the unit fail
to operate. An explanation of each status message and fault
can be located in HeatNet Control Manual under status screen
fault display section.
STATUS SCREEN FAULT DISPLAY
Th ere are numerous interlock switches and soft ware limits that are
detected. Each of these, when tripped will produce a display message,
an audible beeping, and an alarm relay closure. Th e fault is displayed
fi rst, then aft er a second, the time the fault occurred is displayed.
Th is cycle will keep occurring until the fault is cleared. Th ese faults
are:
HIGH LIMIT:
When the high limit aquastat trips the following
message is displayed:
FAULT
SYSTEM SET
160˚F
HIGH LIMIT
FAULT
SYSTEM SET
160˚F
10/27 9:16
Th e high limit interlock breaks power to the ignition control
(shutt ing it off ) and eff ectively removes any chance of the gas valve
receiving power. Th e FIII series control will remain powered to
display the fault, latch the alarm relay/audible beeper, and to access
the log. Th e interlock is located on J5, HIGH LIMIT.
INTERLOCK SPARE 3:
Th is is a reserved interlock input that is
normally jumpered at the factory, but can have a remote interlock
connected as a fi eld install. Th e interlock is located on J11A, SPARE 3.
FAULT
SYSTEM SET
160˚F
INTERLOCK SPARE 3
LOW WATER CUTOFF:
If there is a low water condition reported
by the low water cutoff switch this fault is displayed. Check that
there is water fl ow and water in the boiler. Th ere is a reset switch
located on the LWCO box. Th e interlock connection is located
on J11A, LWCO.
FAULT
SYSTEM SET
160˚F
LOW WATER CUTOFF
