If you are on the RoboTower, you can check that it's in LAND mode, using the display of the handset of the RoboDIMM telescope. Toggle through the menu by pressing the MODE key until you see "telescope", as follows:

MODE    key ->TELESCOPE  <enter>
next item   SITE 
scroll down to Align and press
next item  AZALT
 LAND           ./
scroll down to see a tick against LAND. 

If it's not, then select LAND using <enter>

(The MODE key is in the middle of the top row of button and the Scroll down key is on bottom right of the keypad.)

Close the entry hatch as you leave. You can close the dome as you are leaving the WHT in your car at the end of a normal night.