TECHNICIAN’S QUICK REFERENCE GUIDE
69-1957—1
L7224 Series
Oil Electronic
Aquastat® Controller
The following service procedure provides a quick overview for
L7224 Series Controllers. For more information, refer to form
69-1384.
On the L7224U the High Limit, High Limit Differential, Low Limit,
and Low Limit Differential can be adjusted to the settings
recommended by the boiler OEM.
Adjusting Settings
To discourage unauthorized changing of Aquastat® settings, a
procedure to enter the adjustment mode is required. To enter the
adjustment mode, press the
UP
,
DOWN
, and
I
buttons
simultaneously for three seconds. Press the
I
button until the
feature requiring adjustment is displayed:
•
HL—High Limit.
•
LL—Low Limit.
•
Ldf—Low Limit differential.
•
F - C—°F or °C.
Then press the
UP
and/or
DOWN
buttons to move the set point to
the desired value. After 60 seconds without any button inputs, the
control will automatically return to the READ mode.
To use the L7224U in a cold start boiler application, disable the
Low Limit function by pressing the
UP
arrow button,
DOWN
arrow
button and
I
buttons simultaneously for three seconds. Then push
the
I
button until
LL
is displayed. Then press the down arrow
button until
OFF
is displayed.
Display
In the RUN mode, the Aquastat® will flash “bt” (boiler temp)
followed by the temperature (i.e., 220), followed by °F or °C.
To read boiler settings, press the
I
key to read the parameter of
interest. For example, press
I
(HL) High Limit is displayed,
followed by a three-digit number, i.e., 220, followed by °F or °C.
69-1957-1.fm Page 1 Tuesday, June 20, 2006 11:06 AM
