IBC VFC 15-150 Installation And Operating Instructions Manual page 62

5.3.5 Miscellaneous
SYMPTOM
FUMES AND HIGH HUMIDITY
BOILER STUCK ON INITIALIZE
TOUCH SCREEN MESSAGE:
Unknown Error
ERROR: WATER HIGH LIMIT /
LOW WATER CUT-OFF WON'T
CLEAR.
DHW TAKING TOO LONG TO
HEAT.
BOILER OUTPUT NOT
MODULATING UP TO
MAXIMUM DESPITE TARGET
NOT BEING REACHED.
PRIMARY PUMP RUNS
DURING PARALLEL-PIPED
DHW CALL.
5-10
VFC 15-150, VFC 45-225 MODULATING GAS BOILERS
DIAGNOSIS
Improperly installed
condensate trap
Leak in vent piping
Flue gas leak within
boiler
Fan board failure
Temperature sensor
input problem.
Boiler is in 1 hour
safety lockout.
Sensor may be under-
reading actual water
temp.
Possible flow issue:
check for 35 or 40
degree F temperature
difference between
boiler supply and return
water temperatures
(evokes electronic
fence).
Load definition as DHW.
REMEDY
Refer to installation/operation instructions
Inspect using soap solution
Visually inspect all mechanical connections
Replace fan.
Test each temperature sensor for appropriate
readings and replace defective temperature
sensor.
Reset safety device and cycle boiler power off
and on to reset error.
Check sensor engagement; note well is 15cm /
almost 6 inches deep and sensor must be fully set
to back. Check programmed settings boiler temp
set too close to the required DHW temp
Confirm that primary pump is able to overcome
head loss of boiler and primary loop piping at the
required flow rate.
On Touch Screen Controllers set the boiler pump
to off in the Installer Set-up Menu.
INSTALLATION AND OPERATION INSTRUCTIONS