Honeywell AQ251 Manuale Utente

69-1979—04

2

Canadian Standards Association: Certified, File No. LR76030

AQ1000: non-programmable zone thermostat

AQ15100B: Replacement Boiler Reset Control Module

AQ15740B: 4-zone valve expansion module

AQ15540B: 4-zone pump expansion module

AQ10X38: 24 Vac 38 VA transformer 

AQ12C10: Replacement sensor, outdoor

AQ12C11: Replacement sensor, supply and return on boiler 

loop

AQ12C20: Replacement floor / slab sensor

The AQ251 User Interface consists of an LCD screen (16 

characters by 3 rows) and a 7 button keypad for navigating 

the menus as illustrated in Fig. 1.

The 7- button keypad provides the following functions.
Menu

Press this button to access the User Menu. When 

pressed while in a sub-menu, the sub-menu’s 

values are saved before going up one level in the 

current menu.

Press this button to leave the User or Installer 

Menu and return to the Home Page display screen.

Press this button to enter a sub-menu of the active 

menu item. A menu item is active when the 

indicator arrow 

(←) is positioned beside the item.

and v

Press these buttons to scroll up/down in the menu 
items. Pressing one of these buttons automatically 

exits the edit mode, and the selection moves to the 

previous or next menu item.

– and +

Press these buttons to decrease/increase the value 

of a selected menu item, or to scroll through a list of 

pre-defined options.

- If the menu item being modified is a number, the 

displayed value will decrease/increase by pressing 

these buttons. When holding the – or + button for 

more than a second, the values automatically 

decrease/increase at a faster pace, similar to 
setting the time on a digital clock radio

.

- If the menu item is an option, pressing these 

buttons scrolls through the list of available options 
one at a time.

AQ25142B

Reset Boiler Control Panel 

with integrated zoning 

Selectable DHW priority, with 

optional priority override

2 – 16, 

in sets of 4

Line voltage circulators or 2-wire zone 

valves

AQ25144B

Reset Boiler Control Panel 

with integrated zoning 

Selectable DHW priority, with 

optional priority override

2 – 16, 

in sets of 4

24 Vac zone valves with end switches

AQ25110B

Reset Boiler Control Panel 

with no integrated zoning

Selectable DHW priority, with 

optional priority override

1

None; user can add zoning with 

Expansion Zoning Panels (sold 

separately)

ARROW INDICATES 

THE CURRENTLY SELECTED 

“ACTIVE” MENU ITEM.

M27748

UP ARROW, IF DISPLAYED, 

INDICATES THAT OTHER MENU 

ITEMS EXIST ABOVE AND CAN 

BE VIEWED BY SCROLLING 

UP WITH THE       BUTTON.

DOWN ARROW, IF DISPLAYED, 

INDICATES THAT OTHER MENU ITEMS 

EXIST BELOW AND CAN BE VIEWED 

BY SCROLLING DOWN WITH 

THE      BUTTON.

- CALL FOR HEAT

- CALL FOR DHW

- SIGNAL ON AUXILIARY INPUT

- AUXILIARY OUTPUT ACTIVE

- BOILER T-T OUTPUT ACTIVE

DISPLAY AREA SHOWING  

SYSTEM STATUS AND MENU  

OPTIONS AND SELECTIONS  

MADE 

- PRIMARY (BOILER) HEAT

- DHW PUMP

- AUXILIARY “PUMP” OUTPUT

GRAPHIC SHOWING 

THE PERCENTAGE 

OF THE BOILER’S 

HEATING CAPACITY 

AT WHICH IT’S 

OPERATING; ARROWS

ABOVE AND BELOW

THE BAR SHOW THE 

TREND OF THE 

BOILER’S 

TEMPERATURE 

(UP OR DOWN)