Specifications

AQUATROL Zoning System
208 customer.honeywell.com 70-6910
AQ25A Programmable Relay Control Panel for
Hydronic Zoning System
The AQ25A family of AQUATROL Programmable Relay Boiler
Controls provides simplified, energy-efficient control of single-
temperature, residential hydronic heating systems. The AQ25A
easily converts a single zone heating system into a room-by-room
comfort control system, or upgrades a basic, relay-logic zoning
system to intelligent Zone of Greatest Demand control for in-
creased energy efficiency with reduced boiler cycling. AQ25A
boiler controls can ensure ample supply of hot water for both
space heating and priority generation of domestic hot water for
bathing, dishes and laundry.
• Use with AQ1000 2-wire dry contact communicating thermostats and
most digital thermostats.
• 0-10 Vdc modulating output for driving a modulating/condensing
boiler.
• Displays outdoor temperature on all AQ1000 Series thermostats
when used with an AQ12C10 outdoor sensor (included).
• Intuitive programming interface and armchair programming (can be
programmed at your desk and taken to the job site "ready-to-install").
• Customizable control settings and schedules allow for greater level
of control and comfort.
• Controls up to 2 stages of heat from a single thermostat.
• Central programming of zone set points and setbacks
• Zoning Control for up to 4 zones as shipped; can be expanded to a
total of 16 zones with AQ255 or AQ257 expansion zoning panels,
and up to 64 zones when used with AQ254 Add-a-Temperature
panels.
• Zone synchronization through Zone of Greatest Demand control.
• Domestic hot water priority and priority override protection.
• Line or low-voltage output for zoning equipment (pumps or valves).
• Boiler short cycling protection.
• Boiler post purge.
• Freeze protection.
• Pump/valve exercise.
• Boiler shock prevention from cold water returning to boiler.
• Automated test and purge feature for quick start-up and simplified
troubleshooting.
• Integral 38 VA transformer with self resetting electronic fuse.
• 2 hour power supply (super-capacitor) to retain day and time settings
during power outage.
• Non-volatile EPROM memory retains program settings during power
outage.
Application: Boiler control for zoned hydronic systems
Dimensions, Approximate: 16 1/2 in wide x 8 in. high x 3 3/8 in deep
(42 cm wide x 20.3 cm high x 8.5 cm deep)
Power Supply: 120V/60Hz
User Interface (Setting, Programming): (LCD Display and a 7 button
Key Pad) (DIP Switches on zoning modules)
Electrical Connections (Line Voltage): Wire-clamp screw terminals,
Maximum 2 x 14 AWG each on line voltage terminals
Control and Zoning Panel Temperature Rating: 32 F to 130 F (0 C to
55 C)
Thermostat Compatibility: AQ1000 Series 2-wire communicating
thermostats and most digital thermostats
Zone Module Thermostat input: Low voltage, Class II, 2-wire polarity-
insensitive, digital communicating with power link to AQ1000 series
thermostat.
Setback Program: 7 day, up to 2 setback periods/day.
Boiler Heat Post Purge: Off, 10 seconds to 30 minutes (factory default
is 30 seconds)
Boiler (T-T) Output Rating: 24 Vac, 0.5A, 12VA
Boiler Differential: 2F to 41F (1C to 23C), or Auto (minimum 2 minutes
on time)
DHW Demand Input: External dry contacts connection only
Pump/Valve exercise: 30 seconds per 2 weeks of space heating
inactivity
Auxiliary Pump Output Rating: Dry contact output, 120 Vac/250 Vac
5A, 1/3 HP
Auxiliary Low Voltage Output Rating: 24 Vac, 0.5A, 12VA
Auxiliary (Demand) Input: External dry contacts connection only
Zone Output Contact Rating: Pumps: 120 Vac/250 Vac, 5A, 1/3 HP
Valves: 24 Vac, 0.5 A, 12 VA
Sensor Temperature Rating: -58 F to +230 F (-50 C to +110 C)
Supply/Return Sensor: Lead Length: 10 ft. (3050 mm). 10 kilohm NTC
thermistor at 25 C (77 F) ±0.5F (±0.3C) up to 500 ft (150 M) using 18
AWG or larger wire
Heat Demand (Thermostat R-W) Input: External dry contacts
connection only
B-B Communication Bus Terminals: Low voltage, Class II, 2-wire
polarity-insensitive, digital communicating link to other Control or
Zoning modules.
R-
C Input (on Control and
Zoning Modules): 24 Vac Class II (input
on Control and Zoning Modules)
R-C Output (on transformer): 38 VA, 24 Vac Class II
Operating Humidity Range (% RH): 5 to 90% RH, non-condensing
Weight: 5.7 lbs (2.6 kg)
Approvals:
Canadian Standards Association: CSA C/US Certified to CSA and
UL Standards, File No. LR76030
Product Number
Type of Zoning
Devices
Controlled
Number of
Zones
Controlled
Boiler Pump
Output Rating
DHW Pump/
Valve Output
Rating Replacement Parts
AQ25A42B Zone pumps or
2-wire valves
(line voltage)
4 120 Vac/250 Vac
5A, 1/3HP
120 Vac/250 Vac
5A, 1/3HP
AQ15A00B boiler control module
AQ12C11 supply/return/mixed loop sensor
AQ12C10 outdoor sensor
AQ10X38 24 Vac 38 VA transformer
AQ15540B 4-zone pump expansion module
AQ25A44B Zone valves with
end switches
4 120 Vac/250 Vac
5A, 1/3HP
120 Vac/250 Vac
5A, 1/3HP
AQ15A00B boiler control module
AQ15740B 4-zone valve with end switch expansion module
AQ12C11 supply/return/mixed loop sensor
AQ12C10 outdoor sensor
AQ10X38 24 Vac 38 VA transformer