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