Honeywell AQ25242B Aquatrol Universal Injection/Mixing Boiler Reset Control Panel w/ DHW Priority

The AQ252 family of AQUATROL Universal Injection/Mixing Boiler Reset Controls provides simplified, energy-efficient outdoor temperature compensated control of single-temperature, residential hydronic heating systems. The AQ252 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 with outdoor reset for increased energy efficiency with reduced boiler cycling. AQ252 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.

Features

• Controls one boiler loop and one mixed temperature loop.
• Use of variable speed injection pump or motorized mixing valve for mixed temperature loop control.
• 0-10 Vdc modulating output for driving a modulating/condensing boiler or a modulating mixing valve.
• Displays of outdoor temperature on all AQ1000 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.
• Central programming of set points and setback.
• 1- or 2-stage zoning.
• Zoning Control for up to four 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 AQ254 Add-a-Temperature expansion panels.
• Outdoor temperature compensation (reset), or Load reset based on indoor temperature feedback.
• 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.
• 4 hours power supply (super capacitor) to retain day and time settings during power outage.
• Non-volatile EPROM memory retains program settings during power outage.

Specifications

• Application: Controls one boiler and one mixing (either variable speed injection or floating valve mixing) loop in a hydronic zoning system.
• Thermostat Capaiblity: AQ1000 Series 2-wire communicating thermostats and most digital thermostats
• Setback Program: 7 day, up to 2 setback periods/day.
• User Interface: LCD Display and a 7 button Key Pad
• Number of Communicating Zones Controlled: 4
• Boiler (Supply) Max. Control Temperature (F): OFF, 120F to 225 F
• Boiler Min. Control Temperature (F): OFF, 59F to 180F
• Outdoor Low Design Control Temperature (F): -60F to 32F
• Return Min. Control Temperature (F): 80 F to 180 F
• Boiler Differential: 2F to 41F (1C to 23C), or Auto (minimum 2 minutes on time)
• Boiler Post Heat Purge: Off, 10 seconds to 30 minutes (factory default is 30 seconds)
• Pump/Valve Exercise: 30 seconds per 2 weeks of space heating inactivity
• Power Supply: 120V/60Hz
• R-C Input (on Control and Zoning Modules): 24 Vac Class II (input on Control and Zoning Modules)
• 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, beta=3892.
• Auxiliary Imput: External dry contacts connection only
• Boiler (T-T) Output Rating: 24 Vac, 0.5A, 12VA
• Control and Zoning Panel Temperature Rating (F): 32 F to 130 F
• Operating Humidity Range (% RH): Sensor Temperature Rating (F): -58 F to +230 F
• Boiler Design Temperature (F): 80 to 210F
• Type of Zoning Controlled: Zone pumps or 2-wire valves (line voltage)