Specifications

AQUATROL Zoning System
70-6910 207
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AQ250 Electronic Relay Boiler Control Panel for
Hydronic Zoning System
The AQ250 family of AQUATROL Boiler Controls provides
simplified, energy-efficient control of single temperature,
residential hydronic heating systems. The AQ250 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 increased energy
efficiency with reduced boiler cycling. AQ250 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.
• Controls up to 2 stages of heat from a single thermostat.
• Use with AQ1000 2-wire communicating thermostats, or most dry
contact digital thermostats.
• 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-Temp panels.
• Line or low-voltage output for zoning equipment (pumps or valves).
• Zone synchronization through Zone or Greatest Demand control.
• Domestic hot water priority and priority override protection.
• Boiler short cycling protection.
• Boiler post purge.
• Freeze protection.
• Pump/valve exercise.
• Boiler shock prevention from cold water returning to boiler.
• Automated test feature for quick start-up and simplified
troubleshooting.
• Integral 38 VA transformer with self-resetting electronic fuse.
Application: Boiler control for zoned hydronic systems
Dimensions, Approximate: 13 in wide x 8 in. high x 3 3/8 in deep
(33 cm wide x 20.3 cm high x 8.5 cm deep)
Power Supply: 120V/60Hz
User Interface (Setting, Programming): (DIP Switches)
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.
Boiler Heat Post Purge: 30 seconds (sent to DHW tank or Zone of
Greatest Demand - selectable)
Boiler (T-T) Output Rating: 24 Vac, 0.5A, 12VA
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
Zone Output Contact Rating: Pumps: 120 Vac/250 Vac, 5A, 1/3 HP
Valves: 24 Vac, 0.5 A, 12 VA
ZR-ZC Contact Rating: 120 to 240 Vac, 1/3 HP
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
R-C Output (on transformer): 38 VA, 24 Vac Class II
Operating Humidity Range (% RH): 5 to 90% RH, non-condensing
Weight: 4.9 lbs (2.3 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
AQ25042B Zone pumps or 2-wire
valves (line voltage)
4 120 Vac/250 Vac
5A, 1/3HP
120 Vac/250 Vac
5A, 1/3HP
AQ15000B boiler control module
AQ12C11 supply/return/mixed loop sensor
AQ10X38 24 Vac 38 VA transformer
AQ15540B 4-zone pump expansion module
AQ25044B Zone valves with end
switches
4 120 Vac/250 Vac
5A, 1/3HP
120 Vac/250 Vac
5A, 1/3HP
AQ15000B boiler control module
AQ15740B 4-zone valve with end switch expansion module
AQ12C11 supply/return/mixed loop sensor
AQ10X38 24 Vac 38 VA transformer