Honeywell aquastatic l7224 사용자 설명서

69-1957—1

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.

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.

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