Cycling Issues - IBC Sl Series Installation & Operating Manual

Issue
Boiler pump runs but load pumps do
not.
Boiler stuck on initialize
Boiler pump runs during parallel-
piped DHW call

8.3.4 Cycling issues

Issue Diagnosis
Rapid Improper values
Cycling entered via keypad.
Excess condensate
in venting.
Obstruction in
condensate trap.
Improper vent
length or improper
slope to vent.
Incorrect settings or
defective
thermostat.
Air in system or
marginal water
flow.
Slow combustion
air blower.
Dirty burner/heat
exchanger.
Low water flow due Refer to recommended piping for the respective boiler model.
Miscellaneous issues
Diagnosis
Wiring not Supply power to the PV/L and PV/N
complete. terminals from the incoming power
supply to the boiler. (Factory wired on
boilers with a factory installed
touchscreen controller)
Fan board Replace the fan.
failure
Boiler pump is Re-define the DHW load as DHW Loop
set to On. 2 (5 button controls) to turn off the boiler
pump during domestic hot water calls.
On touch screen controllers, set the
boiler pump to Off in the Installer Setup
menu.
Cycling issues
Check load maximum temps are above target temps, by ½ of the
selected boiler differential. Ensure boiler differential is OK (16 - 30
°F is generally adequate)
Check venting slopes on horizontal runs. Look for sags.
Inspect and clean condensate trap.
Check venting. Compare vent length and diameter.
Check operation. Refer to manufacturer's instructions. Check
setting with ammeter.
Bleed/purge system as required. Confirm adequate pump size and
temp rise in the heat exchanger.
Check that CO level is within specification.
2
Check pressure drop.
99
8.3.4 Cycling issues
Fix
Fix