Honeywell AQ251 User Operation And Maintenance page 7

LCD Display
NO RETURN PROBE
NO SUPPLY PROBE
SHORT CYCLE PROT
VALVE INIT
WATER READY
WWSD ACTIVE
When a new AQ2000 component is connected on the
AQUATROL network, its settings are communicated to the
AQ251's Boiler Control Module (AQ1520M0) within 10
seconds of being connected. If the component is an AQ1000
thermostat, the setpoints for that zone thermostat can be
modified from the Boiler Control Module as soon as it is
recognized by the Control Module.
Table 2. LCD Status Notices and Error Messages. (Continued)
Parameter
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.
AQUATROL ZONE SYNCHRONIZING BOILER RESET CONTROLS
Meaning
When an AQ thermostat is disconnected from the AQUATROL
network, a message displays on the System Status page of
the AQ251 indicating "Lost Zone A-xx", where "xx" is the
specific identity, or address, of the lost zone. This helps the
servicing contractor quickly identify the lost zone and fix its
wiring, to re-establish communication with the Control Module.
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