AQUATROL Zoning System
AQ250 Electronic Relay Boiler Control Panel for Hydronic Zoning
System
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.
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
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)
Powe r Sup ply: 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 Pump/Valve Output Rating: 120 Vac/250 Vac 5A, 1/3HP
DHW Demand Input: External dry contacts connection only
Pump/Valve exercise: 30 seconds per 2 weeks of space heating
inactivity
• 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.
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
Controls
Hydronic
Product Number
* AQ25042B/U Zone pumps or 2-wire
* AQ25044B/U Zone valves with end
* TRADELINE models • SUPER TRADELINE models
Type of Zoning
Devices Controlled
valves (line voltage)
switches
Number of Zones
Controlled
4 120 Vac/250
4 120 Vac/250
Boiler Pump
Output Rating Replacement Parts
Vac 5A, 1/3HP
Vac 5A, 1/3HP
70-6910 185
AQ15000B boiler control module; AQ12C11 supply/return/mixed loop
sensor; AQ10X38 24 Vac 38 VA transformer; AQ15540B 4-zone
pump expansion module
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