This is the first setting described in "About Manual"
As before we start from the default screen, which will be similar to one of the images below. You may note that the middle image has the system running in automatic with both boost and circulate on.

Press the info key (key 7). You are now in the main menu, and the screen will be the same as the image below.

Press the down arrow key (key 6) seven times. Please note, the up and down arrow keys can be used to scroll through all the menu options.
The screen will now be the same as the image below.

Press the right arrow key (key 5). If the screen is not the same as the image below, press the up, or down arrow keys (keys 4 or 6) until "Circ Ceil Only" is displayed.

Pressing the enter key (key 8) now will make this the selection used when manual mode is set. Pressing the left arrow key will return you to the main menu without changing the current manual setting.