Troubleshooting Guide - IBC VFC 15-150 Manual

5.3.1 Using Control Module Errors Displayed
SYMPTOM
AIRFLOW ERROR
LCD Screen Message:
Error – Insufficient Air Flow -
Check Venting
Insufficient combustion airflow;
soft error; will retry in 5 minutes
WARNING
Never attempt to repair
the control module (circuit
board). If the control module
is defective, replace it
immediately.
WATERFLOW ERROR
LCD Screen Message:
Error - No Water Flow
Low water flow – soft error; will
retry in 5 minutes
5-6
VFC 15-150 - VFC 45-225 MODULATING GAS BOILERS

5.3 trouBlesHooting guide

DIAGNOSIS
Check fan operation
Check for fouled
reference lines and air
sensor
Check achieved fan
power
Water noise in vent.
Excess condensate in
venting.
Check pressure
sensors
Check for proper
piping
Check primary pump
Check for restriction
in water pipe
REMEDY
• Check lead is attached at fan.
• Cycle power off/on; listen for fan initialization.
if no action, focus your attention on the fan
itself.
• Check clear vinyl air reference lines below
gas valve for any sign of water. after
disconnecting from black sensor, blow clear.
Check for exhaust re-ingestion, or repeated
power interruptions .
• Ensure condensate trap is not blocked.
• Go to Advanced Diagnostics and check
differential air pressure sensor (at rest and
with fan on). see Section 5.2.3.
in advanced diagnostics, during Pre-purge, Fan
Pressure (FP) should move close to required
Pressure (rP); if FP only 120-150 vs. rP of
250 or 300, then check for actual vent system
blockage: (a) disconnect intake within boiler
case; (b) open burner then fan/gas valve looking
for debris.
• Check condensate trap for obstructions.
Remove obstructions and refill condensate
trap with water.
• Check vent length, size and configuration,
particularly re: horizontal 2" piping.
• Check wiring: water pressure sensors to
controller.
• Check pressure sensors. See Section 5.2.4
– 2nd paragraph.
refer to Section 1.6 Water Piping for
recommended piping installation.
if there is a valve on the primary loop, close it
and listen for cavitation (evidence flow). If not,
go to installer setup; select pump purge "on" to
run pumps without a heat call - check for heat
buildup at pump body (indicates no flow).
Check temperature differential across heat
exchanger at low –medium firing rate if possible.
examine air strainer components for scale.
INSTALLATION AND OPERATION INSTRUCTIONS