35
is section provides a brief description of the key controls
and accessories found in this boiler.
See the Troubleshooting section of the Service Hints chapter
of this installation manual for detailed sequences of operation
and troubleshooting procedures. See the Repair Parts chapter
of this manual for locations of all control components and ac-
cessories described.
e Integrated Boiler Control (IBC) is a microprocessor based
controller for a high eciency gas boiler that monitors all
safety controls and which controls the operation of the com-
bustion air blower, circulator pump, burner, and a combination
hot surface igniter/ame sensor. is controller is not intended
for use with a vent damper. is controller is mounted on the
control panel inside of the boiler and contains ve (5) diagnos-
tic indicator lights.
e electrically controlled 24 Volt Honeywell Model VR8205
Combination Gas Control Valve is designed to meet the re-
quirements for use with hot surface ignition systems found in
this boiler. e valve is piped to the gas/air mixer.
e 120 Volt Hot Surface Igniter heats up to 1800 °F to initiate
combustion of the gas in the burner. e igniter is mounted
next to the burner through the gas/air mixer. e igniter also
serves as a means for proving the main burner ame by ame
rectication. In the event of a lack of ame signal on three
(3) consecutive trials for ignition, the IBC will lockout. e
“VALVE” and “FLAME” diagnostic indicator lamps (lamp “D”
and “E” on the IBC, See Figure #16) will blink indicating the
failure mode as a lack of ame signal. e IBC is manually
reset from lockout by either removing and reestablishing the
thermostat’s call for heat, or by turning the service switch o,
then back on.
e High Limit Aquastat Control determines the maximum
boiler water temperature and also provides a means for
protecting the boiler and heating system from unsafe operat-
ing conditions which could damage the boiler. e aquastat
is mounted in the ½” NPT control well and ¾”x½” bushing
on the top of the front boiler section at the hot water outlet.
e aquastat is tied in with the IBC and is factory set at 180 °F
water temperature. e high limit setpoint is eld adjustable
and may be set anywhere between 100 °F and 200 °F. e eld
setpoint adjustment for each installation depends on heating
system requirements. e aquastat automatically resets when
the boiler water temperature decreases (5-30 °F adjustable
dierential). e dierential can be adjusted with the (white)
Dierential Adjustment Wheel on the aquastat and gives the
exibility for boiler operation. e larger the dierential, the
longer the run cycle of the boiler.
NOTE: e maximum setpoint of the Aquastat must not
exceed 200 °F.
e Dra Inducer Temperature Safety Switch is a disc thermo-
stat (180 °F setpoint) located on the induced dra fan outlet
port. e switch protects the inducer and vent pipe from a
potential high temperature condition for the discharging ue
gases. is condition would typically be a result of higher
aquastat setting or over ring. e temperature safety switch
automatically resets when the higher aquastat setting or over
ring. e temperature safety switch automatically resets when
the vent temperature decreases. (15 °F switch dierential).
In the event of lack of or loss of water in the boiler, the Cast-
ing Temperature Safety Switch (300 °F setpoint) installed on
the top of the aluminum boiler section shuts o the boiler by
shutting o power to the Integrated Boiler Control (IBC) and
causes the Power Indicator Light to go out. is fault requires
manual reset of the casting temperature safety switch to restart
the boiler. Verify that the boiler is properly lled with water
before resetting this switch. WARNING-Never run cold water
into a hot empty boiler.
All 90 Series Hot Water Boilers come equipped with either one
(100 Series) or two (200 Series) diaphragm-type dierential
pressure switches. e dierential pressure switch monitors air
ow by sensing the dierential pressure measured in inches
of water (” w.c.). e pressure switch contacts close when the
dra inducer is running. e closed switch proves there is
adequate air ow for combustion. e pressure switch shuts o
the main burner if the dierential pressure is inadequate due
to a blocked vent pipe, a blocked air intake, blocked boiler sec-
tions, or a blocked dra inducer. Aer ve (5) minutes of lack
of adequate dierential pressure, the IBC will lock out and the
“Purge” indicator light will blink, indicating a failure to prove
To Next Page
Loading...
Need help?
General
