Appendix; Troubleshooting - Honeywell AQ250 Series Quick Installation Manual

APPENDIX

Troubleshooting

Communications Loss
A possible failure mode of the AQ250 would be loss of
communication between the Control Module and any Zoning
Modules or between a Zoning Module and any zone
thermostats that have previously been connected to the
AQUATROL network. In general, the Control will:
• Periodically try to re-establish communication with any
"lost" components on the network;
• Initialize any component that re-establishes its
communication.
CONTROL MODULE REACTION
When the AQ1500B0 Control Module loses communication
with any number of zones (as long as there's still at least one
zone communicating on the AQUATROL network), the AQ250
will continue to deliver heat to the other 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 pump for a period of 4
minutes every hour. This should provide sufficient heat to the
system to prevent a building from freezing up until someone
re-establishes the communication between the AQ2000
components.
DIAG LED Status
Steady (no blinking)
Fast blinking (4 blinks / second)
Slow blinking (2 blinks / 3 seconds)
Coded blinking = ERROR
• 2 blinks then pause
• 4 blinks then pause
• 5 blinks then pause
DIAG LED Status
Steady (no blinking)
Fast blinking (4 blinks / second)
Slow blinking (2 blinks / 3 seconds)
Coded blinking = ERROR
• 2 blinks then pause
• 3 blinks then pause
Table 5. AQ1500B0 Control Module Error Codes:
System Condition
No system problem detected
Auto Test is in operation
Auto Test has been "paused"
Freeze protection activated
across AQUATROL network
Return sensor open / short
Supply sensor open / short
Table 6. AQ155 / AQ157 Zoning Module Error Codes:
System Condition
No system problem detected
Auto Test is in operation
Auto Test has been "paused"
Freeze protection activated on
the Zoning Module
Communication lost with ALL
thermostats
15
AQ250 SERIES HYDRONIC CONTROL PANELS
ZONING MODULE REACTION
When a Zoning Module loses communication with the Control
Module, the Zoning Module operates its pumps or valves in a
"conventional, non-synchronized" zoning fashion i.e.
according to the demands from the thermostats, without
waiting for the "permission" from the AQ1500B0 Control
Module to operate. This allows the zones to extract any heat
provided by the boiler.
When communication is lost between a Zoning Module and
one of its thermostats, that zone is "invisible" to the Control
Module; the Zoning Module stops serving that zone and the
zone's pump or valve is de-energized.
The AQ250 provides Control Module diagnostic information
via the DIAGNOSTIC LEDs located above the DIP switches
on the AQ1500B0 Control Module.
The AQ250 provides Zoning Module diagnostic information
via the DIAGNOSTIC LEDs located above the DIP switches
on its Zoning Module(s).
This information helps the installer correctly identify system
problems, making troubleshooting much faster. The following
tables describe the possible error codes that can be displayed
on the AQ1500B0 Control Module and AQ155 / AQ157
Zoning Modules.
Action Required
None
None. Permit the control to finish Auto Test routine
Press the Test button to resume Auto Test routine
All zones have lost communication with controller – check
B-B wiring between Control Module and Zoning Module
Check the return sensor wiring
Check the supply sensor wiring
Action Required
None
None. Permit the control to finish Auto Test routine
Press the Test button to resume Auto Test routine
Zoning module has lost communication with controller –
check B-B wiring between Control Module and Zoning
Module
Check thermostat wiring to Zoning Modules
69-1982