Honeywell AQ250 Catalog Page

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