RBI Gas boilers - Control System Description; Low Water Cutoff Device; Operating Control Settings; High Limit Aquastat

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CONTROL DESCRIPTION
Low Water Cuto
If the boiler is to be installed above radiation or if required by other
codes or regulations, install a low water cuto in appropriate piping.
Wire the switch to the “Interlock” contacts as illustrated on “Field
Wiring” schematic. Ensure that the low water cuto device(s) will
function properly.
Operating Control
 e preferred control se ing for potable hot water is 130°F, 54°C.
 e operating control should be set to the lowest se ing that will
satisfy the consumer’s needs.
Se ing the thermostat or operation control too high
can result in scalding resulting in severe personal
injury!
High Limit (Aquastat)
 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.  e high limit can be reset by depressing the
red bu on.
 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  ow switch is provided in the water outlet piping to prevent
the boiler/water heater from  ring without adequate water  ow
through the heat exchanger.
DIAGNOSTICS
 e Futera Fusion has a display that indicates the sequence of
operation.  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
 ere are numerous interlock switches and so ware limits that
are detected. Each of these, when tripped will produce a display
message, an audible beeping, and an alarm relay closure.  e fault
is displayed  rst, then a er a second, the time the fault occurred
is displayed.  is cycle will keep occurring until the fault is cleared.
 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
 e high limit interlock breaks power to the ignition control
(shu ing it o ) and e ectively removes any chance of the gas valve
receiving power.  e Futera Fusion series control will remain
powered to display the fault, latch the alarm relay/audible beeper,
and to access the log.  e interlock is located on J5, HIGH LIMIT.
INTERLOCK SPARE 3:  is is a reserved interlock input that
is normally jumpered at the factory, but can have a remote inter-
lock connected as a  eld install.  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 cuto switch this fault is displayed. Check that
there is water  ow and water in the boiler.  ere is a reset switch
located on the LWCO box.  e interlock connection is located on
J11A, LWCO.
FAULT
SYSTEM SET
160˚F
LOW WATER CUTOFF