Honeywell AQ25A Series Technical Reference Booklet page 67

AQ251 Series Boiler Reset Control Panels
PRODUCT DESCRIPTION
The AQ251 Series of AQUATROL® Boiler Reset Controls
provides simplified, energy-efficient outdoor temperature
compensated control of a high-temperature boiler loop in
residential hydronic heating systems. The AQ251 easily
converts a single-zone heating system into a room-by-room
comfort control system. The boiler controls of the AQ251 can
ensure ample supply of hot water for both space heating and
priority generation of domestic hot water for bathing, dishes
and laundry.
FEATURES
The AQ251 Series has the following features:
• Outdoor temperature compensation (reset), or Load
reset based on indoor temperature feedback, or none
• Domestic hot water (DHW) priority and priority
override protection.
• Customizable control settings and schedules allow for
greater level of control and comfort.
• Central set-back schedules available.
• Zoning Control for up to four, single-stage zones or
two, two-stage zones as shipped; can be expanded to
a total of 16 zones with AQ255 or AQ257 expansion
zoning panels, and up to 64 zones by using up to three
AQ254 Add-a-Temperature expansion panels and
additional expansion zoning modules.
• Use with digital non-communicating thermostats or
AQ1000 2-wire polarity insensitive communicating
thermostats.
• When using non-communicating thermostats, the
following features are not available:
• Outdoor temperature is not displayed on the
thermostat.
• Time clock on AQ1000TP2 will not synchronize
with the Control Module.
• Central programming, vacancy and setback
schedules of AQ1000 from AQ panel are not
enabled.
• AQ panel will not display individual zone
temperatures.
Specifications ...................................................................
1 Installation Preparation ..................................................
2 Mounting ........................................................................
3 Wiring Procedure ...........................................................
4 Program and Configure the Control Panel .................... 14
5 Test and Check Out the Installation ............................... 18
6 Purge Air from all System and Zone Piping .................. 19
7 Document and Keep a record of all System Settings .... 20
Troubleshooting ................................................................ 20
Appendix .......................................................................... 23
User Menu .............................................................. 23
Installer Menu ......................................................... 30
PRODUCT DATA
Contents
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