Sequence Of Operation - IBC HC Series Installation And Operating Instructions Manual

NOTE
The boiler is equipped with
a Frost Protection feature.
This feature will operate
the boiler pump and the
burner to help protect the
boiler from freezing. If the
boiler is in a hard lock-out
condition the burner will not
operate, however the boiler
pump will operate. IBC is
not responsible for damages
to the boiler, and/or related
components, nor property
damages that may result from
freezing conditions.
2-6
HC SERIES BOILERS HC 13-50, HC 23-84, HC 29-106, HC 20-125, HC 33-160
2.7

SEQUENCE OF OPERATION

The boiler will operate in a similar way for both a space heating and a domestic
hot water call for heat. When the boiler is powered up the controller enters a self
diagnostic mode and displays 2 in the Service Display.
The Sequence of Operation is as follows:
1.
The boiler receives a call for heat from closing terminals X4.6 and X4.7 (24
volts). The boiler can also receive a call from Domestic Hot Water heating
from the closing terminals, X4.9 and X4.10 (24 volts) (10KΩ sensor or
aquastat)
2.
The boiler does a safety check and energizes the fan for a pre-purge
(Service Display = 3)
3.
Once the 5 second pre-purge is compete, the boiler enters a 5 second trial
for ignition (Service Display = 4). If the boiler fails to ignite, the boiler will
compete a 5 second inter-purge then another 5 second trial for ignition. This
is repeated 4 times before a hard lock out occurs. The Reset button
must be pressed to reset the controller and allow for another attempt.
Once the burner is lit and flame has been proven the boiler operates as it is
4.
programmed (Service Display = 5 for Space Heating or 6 for Domestic Hot
Water)
5.
If the boiler reaches its target temperature and there is still a call for heat or
hot water. (Service Display = 1)
6. After the call for heat is satisfied, the boiler pump will operate for an
adjustable amount of time (Service Display = 0)
7.
If the burner is on to maintain the heat exchanger temperature for DHW
Comfort mode or for Freeze Protection mode (Service Display = 7)
8.
If the burner is on for Frost Protection (Service Display = 9)
MAIN
DISPLAY
[Pressure]
(blank)
XXX
XXX
XXX
XXX
XXX
XXX
XXX
XXX
Table 8: Operating Display and Service Display Codes.
SERVICE DESCRIPTION
DISPLAY
- The boiler is OFF. Press the On/Off
on the boiler
(blank) No Call for Heat - Standby
0 Boiler pump running – pump post purge
1 Boiler water temperature reached target – boiler pump is
energized, call for heat still present
2 Self-test – When power is applied to the boiler the
controller enters a self diagnostic mode for 5 seconds
3 Fan Pre-purge , Inter-purge and Post-purge
4 Trial for Ignition and Flame Proving
5 Heating – Space Heating
6 Heating – DHW
7 Burner on for Comfort mode or Freeze Protection mode
INSTALLATION AND OPERATION INSTRUCTIONS
button to turn