Honeywell AQ254 Series Manual page 19

6 PURGE AIR FROM ALL SYSTEM AND
ZONE PIPING
Purging air from all zones in the hydronic system is easily
accomplished with the AQ250 by using a modification to
the Auto Test feature (described in "Auto Test" on page 17)
as follows:
• To purge all zones on the AQUATROL network press the
Test button on the AQ15000B Control Module once to
begin the Auto Test routine. Quickly press it again 3
times until the Boiler relay LED illuminates and the
Diagnostic LED of the AQ15000B blinks slowly (which
indicates the Auto Test routine has been paused). The
boiler pump now remains energized for the duration of
the Purge routine (and therefore can be purging all
loops of air) until the Test button is pressed again.
• The Diagnostic LED blinks slowly while in paused
mode. Continue to purge the boiler loop as long as is
needed to remove air from the system.
• Leaving the boiler pump operating, push the Test
button on the Zoning Module for any space heating
zones you wish to purge.
• With the first zone's output energized (the
LED for Zone 1 illuminates), press the Test
button again to pause the Auto Test routine.
• When Zone 1 has been sufficiently purged,
press the Test button again to begin purging
Zone 2.
• Again, press the Test button to pause the Auto
Test routine while purging Zone 2.
• Continue to purge all other space heating
zones in the system.
If additional purging is required for any zone, the Auto Test
procedure can be activated for any individual Zoning
Module by pressing the Test button located above that
Zoning Module's DIP switches. Refer to "B) Auto Test–
AQ155/AQ157 Zoning Modules" on page 17.
7 DOCUMENT AND KEEP A RECORD
OF ALL SYSTEM SETTINGS
After the AQ250 Series Control Panel and any
AQ255/AQ257 Expansion Zoning Panels have been set up
and the entire hydronic installation is operating properly,
it is important to document all the system settings for
future reference.
Job Records
All AQ2000 Series Panels are shipped with Installation Job
a
Records for documenting these settings.These should be
filled out completely and saved in the Installing
Contractor's files.
a
For the AQ250 Series, refer to AQ25042B RelayPLUS
Zone Synchronizing Boiler Control, (form 69-1972) and
AQ25044B RelayPLUS Zone Synchronizing Boiler Con-
trol (form 69-2030)
AQ250 SERIES HYDRONIC CONTROL PANELS
TROUBLESHOOTING
The following information helps the installer correctly
identify system problems, making troubleshooting much
faster. Table 4 and Table 5 on page 20 describe the
possible error codes that can be communicated on the
diagnostic LEDs of the AQ15000B Control Module and
AQ155/AQ157 Zoning Module.
Communications Loss
Because all AQ2000 Series components communicate
with each other via the dedicated AQUATROL network
when controlling a hydronic system, one possible failure
mode of the AQ250 would be loss of communication
between the AQ15000B Control Module and any
connected Zoning Modules, or between a Zoning Module
and any zone thermostats connected to the AQUATROL
network. In general, the Control Module:
• Periodically tries to re-establish communication with
any lost components on the network.
• Initializes any component that re-establishes its
communication.
CONTROL MODULE REACTION
When the AQ15000B Control Module loses
communication with any number of zones for more than
one minute (as long as there is still at least one zone
communicating on the AQUATROL network), the AQ250
continues to deliver heat to the other non-communicating
zones.
When communication is lost with all zones, the AQ250
enters Freeze Protection mode, in which it fires the boiler
and then activates the Boiler (supply) pump and zone
equipment for a period of 4 minutes every hour. This
should provide sufficient heat to the system to prevent a
building from freezing up until communication is re-
established between the AQ2000 Series components.
ZONING MODULE REACTION
When a Zoning Module loses communication with the
Control Module (as long as there is at least one other
Zoning Module communicating with the Control Module),
the Zoning Module operates its pumps or valves in a
conventional, non-synchronized zoning fashion. That is, it
operates according to the demands from the thermostats,
without zone synchronization or waiting for permission
from the AQ15000B Control Module to operate. This
allows the zones to extract any heat provided by the boiler.
When using AQ1000 thermostats and communication is
lost between a Zoning Module and one of its thermostats,
that zone is invisible to the Control Module, and the
Zoning Module stops serving that zone and the zone's
pump or valve is de-energized.
The AQ250 provides Zoning Module diagnostic
information via the Diagnostic LED located above the DIP
switches on each Zoning Module.
19 68-0306—07