Honeywell AQ25A Series Technical Reference Booklet page 88

AQ251 SERIES BOILER RESET CONTROL PANELS
Table 3. AQ155 / AQ157 Zoning Module LED Display and System Condition.
DIAGNOSTIC LED Status
Steady (no blinking)
Fast blinking (4 blinks per second)
Slow blinking (2 blinks every 3 seconds) Auto Test has been paused.
Coded blinking = 2 blinks,
ERROR then pause
3 blinks,
then pause
LCD Display Parameter
BOILER: EM SHUT Boiler is disabled, because the AQ251 is in Emergency Shut Down mode.
FRZ PROT Boiler freeze protection activated:
HEAT DHW Boiler is active to serve DHW.
HEATING Boiler is active to serve zones.
INST PURG Boiler is active while the AQ251 is conducting the PURGE operation in the Installer Setup.
INSTALL
PMP EXER Boiler is disabled while the AQ251 is exercising all pumps and valves connected to the
CALL FOR COOL
CALL FOR DHW
CALL FOR HEAT
CWSD ACTIVE
DHW DISABLE
LOST ZONE A-1
...
LOST ZONE D-16
NO DHW PROBE
NO OUTDOOR
PROBE
NO RETURN PROBE
NO SUPPLY PROBE
SHORT CYCLE PROT
VALVE INIT
WATER READY
WWSD ACTIVE
69-1974—04
System Condition
No system problem detected
Auto Test is in operation
Freeze protection activated across
the entire AQUATROL network
Communication lost with all
thermostats on the Zoning Module
Table 4. LCD Status Notices and Error Messages.
• Communication between Control Module and Zoning Module has been lost for more
than 1 minute
or
• Boiler supply temperature is less than 50°F (10°C)
IDLE Boiler is not active.
INIT Boiler contacts (terminals 17 and 18) on the AQ151, which are connected to the boiler's T-T
terminals, have been shorted and the boiler is beginning its firing sequence.
Boiler is in ready mode during Installer Setup.
AQUATROL network.
POST Boiler is active with Post Purge operation and is sending the purged water to the Boiler
PURG (Primary) loop.
PURGE Boiler is active with Post Purge operation and is sending the purged water to the DHW tank.
DHW
n/a At least one zone with a programmable thermostat requires cooling.
n/a The DHW requires heat.
n/a At least one zone requires heat.
n/a Zone calls for cooling are not served because CWSD (Cold Weather Shutdown) is in
progress.
n/a DHW call is not served because it is disabled.
n/a Lost communication with a zone (A-1 to A-16, B-1 to B-16, C-1 to C-16, or D-1 to D-16).
n/a No DHW sensor connected or it is defective.
n/a No outdoor sensor connected or it is defective.
n/a No return sensor connected or it is defective.
n/a No supply sensor connected or it is defective.
n/a There is a call for heat, but less than two minutes have elapsed since the last firing of the
boiler (prevents short cycling).
n/a Motorized mixing valve controlling the secondary loop is being initialized and repositioned
(opening or closing) to meet the secondary loop target temperature.
n/a Boiler Supply Water temperature is at or above the target temperature calculated by the
AQ251.
n/a Zone calls for heat is not served because WWSD (Warm Weather Shutdown) is in progress.
None
None. Allow the control to finish its Auto Test routine.
Press the Test button to resume the Auto Test
routine.
All zones have lost communication with the Control
Module. Check B–B wiring between the Control
Module and each Zoning Module.
Check thermostat wiring to each Zoning Module.
Meaning
22
Action Required