IBC VFC 15-150 Manual

INSTALLATION AND OPERATION INSTRUCTIONS
2-6
VFC 15-150 - VFC 45-225 MODULATING GAS BOILERS
temperatureload(e.g.DHWat180°F)toacooltarget(e.g.radiantooron
Outdoor Reset, at perhaps 90°F). In the case in which the temperature is outside
the applicable differentials, the burner will shut off while the pump remains
onuntilwatertemperatureis11°Fbelowthenewload(radiantoor)target
temperature. Thermal shock avoidance routine is employed to avoid undesirable
effects of large temperature swings: the hot load pump remains on until the
boiler’s return water sensor detects temperature stability - to sink excess heat.
For example, upon satisfaction of a DHW call the DHW zone pump will remain
running until the boiler return water temperature falls to the DHW tank target
temperature. This deposits legacy heat from the primary loop into the water tank
beforeactivationofaradiantoorloadpump.
Always ensure that loads sensitive to high temperatures are protected using
appropriate means - e.g. a three way mixing valve set to restrict entering water
temperature to 130°F, or at minimum, an aquastat (set to130°F, for example) to
bewiredtotheboiler’sauxiliaryinterlockstoprotectaradiantoor.
2.5.6 - Error Mode
The controller continually checks sensors to see that they are operating within
normal parameters. If sensors indicate the boiler is operating outside it limits, it
will declare an error condition.
Two types of error conditions can occur:
• Soft Errors: result when an abnormal condition exists which does not present
an immediate safety hazard. The boiler enters an extended purge, followed
by the error cycle of 5 minutes for all conditions other than Maximum Ignition
Trials(amodiedHardErrorwhichlocksoutfor1hourafter3unsuccessful
ignition attempts). Following the purge, the fan and pump are stopped until
the end of the error cycle. Normal operation then resumes.
• Hard Errors: result when a condition exists that may be a safety hazard.
The boiler enters an extended purge then the fan and pump are stopped.
The boiler is in a lockout, and must be checked and restarted by a service
technician.
With software versions 3.10.0 and higher, the boiler offers an error status signal
feature. Please see IBC Technical Note: Boiler Status – Analog Output.
See Section 5.3.1 Control Panel for a list of hard and soft errors and their
likely causes. Note that other problems such as disconnected wires or defective
sensorsmaybethecauseoftheerror.Alwayscheckconnectionsandwiringrst.
OTHER OPERATING FEATURES
2.6.1 Prioritization
The control module hosts a scheduling routine to manage the boiler’s operation
whenmorethanoneloadhasbeendened.Typically,loadsdeclaredasDHW
receivesignicant-butnotabsolute-priority.Atimevs.differentialsystemwill
allocate heat amongst each of up to 3 loads over time.
Multiple heating loads - with varying temperature targets - are run sequentially
as opposed to simultaneously (with a mixing valve). The objective is to serve
each load at the minimum possible temperature, as opposed to running hot
then mixing down – with hardware, saving the related hardware and fuel cost.
2.6
WARNING
This boiler is equipped with
an automatic blocked vent
shutoff system. In the case
of an “Insufcient Airow
Error” event, a licensed and
qualied service technician
shall follow the steps set out
at Section 5.3.1 Airow.

IBC VFC 15-150 Specifications

General

Brand	IBC
Model	VFC 15-150
Category	Boiler
Language	English