IBC Technologies Inc. 45 VFC 15-150 and VFC 45-225
4.3.3 Troubleshooting using the Control
Note: Never attempt to repair the control module. If the control module is
defective, replace it immediately.
Airflow Error
LCD Screen Message:
Error – Insufficient Air Flow -
Check Venting
Insufficient combustion airflow; soft error; will retry in
5 minutes
Check fan operation
• 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 for fouled reference
lines and air sensor
• 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 4.3.2.3)
Check achieved fan power
• 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
Water noise in vent.
Excess condensate in venting.
• Check condensate trap for obstructions. Remove
obstructions and refill condensate trap with water.
• Check vent length, size and configuration,
particularly re: horizontal 2” piping.
Waterflow Error
LCD Screen Message
Error - No Water Flow
Low water flow – soft error; will retry in 5 minutes
Check pressure sensors
• Check wiring: water pressure sensors to controller.
• Check pressure sensors - see Section 4.3.2.4
(2
nd
para)
Check for proper piping
• Refer to Section 1.5 - Water Piping for
recommended piping installation.
Check primary pump
• 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 for restriction in water
pipe.
• Check temperature differential across heat
exchanger at low –medium firing rate if possible.
Examine air strainer components for scale