Honeywell AQ25A Series Technical Reference Booklet page 140

AQ252 Universal Injection/Mixing Boiler Reset Control Panels
Menu Option
MIX DEVICE FLOAT / INJ / 10V
DOMEST.HOT Settings that the AQ252 uses to manage Domestic Hot Water generation
WATER
DHW ENABLE / DISABLE
DHW PRIO YES / NO
PRIO.OVER. YES / NO
DHW DEVICE PUMP / VALVE
DHW VLV.OP 0 - 230 seconds
(in 5 second increments)
DHW PURGE YES / NO
DHW SENSOR YES / NO
DHW SETPOINT - -
60°F to 160°F (16°C to 71°C)
DHW DIFF - -
5°F to 40°F (2.5°C to 22°C)
DHW VACANCY - -
[41°F + DHW DIFF] to 160°F
([5°C + DHW DIFF] to 71°C)
69-1986—02
Table 6. Installer Menu – Equipment Setup. (Continued)
EQUIPMENT SETUP
Factory
Range Default
10V
ENABLE
NO
YES
PUMP
15
(seconds)
YES
NO
140°F
(60°C)
20°F
(-7°C)
45°F
(7°C)
34
Description
Assigns which device is used for mixing to produce the
target temperature in the secondary loop.
Identifies whether Domestic Hot Water Management
function is enabled. DHW is typically disabled only if a
separate source of domestic hot water (e.g., oil, or gas-
fired hot water heater) is used.
Displays only if DHW = ENABLE.
Selects whether DHW generation can take priority over
space heating. If yes, set to YES; if not, set to NO.
Displays only if DHW PRIO = YES.
Selects whether (following a 30 minute uninterrupted call
for DHW Demand) the priority given to DHW generation
can be overridden to minimize the chance of freeze up or
excessive cool down of the space heating zones.
• YES = On = Allow DHW Priority override.
• NO = Off = Do not allow DHW Priority override.
If DHW Priority is selected, Honeywell strongly
recommends setting the DHW PRIOR.OVER to YES.
Displays only if DHW = ENABLE.
Selects whether the DHW loop is supplied by a zone valve
or zone pump.
Displays only if DHW DEVICE = VALVE.
Time required for the DHW zone valve to fully open before
boiler loop pump is energized.
The 15 second default is typical for motorized valves.
Displays only if DHW = ENABLE.
Selects whether or not a purge should be applied after a
DHW demand has been served. If YES is selected, the
DHW pump or valve is kept running for the amount of time
programmed in the PURGE TIME option of the BOILER
OPERATION menu.
Selects whether or not the Return sensor will be used as a
DHW tank sensor. YES = use as the DHW sensor.
Displays only if DHW SENSOR = YES.
Target temperature set for the DHW tank.
• "- -" means Off (not used).
Displays only if DHW SENSOR = YES.
• "- -" means Off (not used).
• A call for DHW begins when the measured DHW
temperature = DHW SETPOINT - DHW DIFF and ends
when the DHW temperature = DHW SETPOINT.
• For example, if the DHW setpoint = 140°F and the DHW
Diff = 20°F, a call for DHW begins when the DHW
temperature falls below 120°F and ends when the DHW
temperature increases to 140°F.
Displays only if DHW SENSOR = YES.
Target DHW temperature when system is in VACANCY
mode.
• "- -" means Off (not used).