Hi Andy, the best way I've found to sort of lock the temp at a setting is to jump into the Nest app and program a temp schedule. It's pretty easy and you can copy-paste one day across the rest of the week.
-Open the Nest app (should be a blue background with a home icon in the top middle and temp readout of one or more of your thermostats below that)
-Click on the thermostat for which you desire a schedule
-Bottom of the screen has "mode/eco/fan/schedule/history"
-Click "schedule"
-Pick a day, like Monday. Click on the row corresponding to Monday. It should expand Monday to fill your screen.
-Click "add" in the lower right corner. Use your finger/stylus and pick a point. Sliding right and left changes the time. Sliding up and down changes the temperature.
-You can probably use a single temp setting to cover the whole day, but if you truly want to lock in a temp, maybe drop three temps (one in the morning, one in the afternoon, one at night)
-Click the arrow in the upper left after you're done with Monday. You'll now see the whole week. Using your finger/stylus, press and hold on Monday.
-Click copy. Press and hold on Tuesday and click paste. Rinse and repeat to fill the week.
Hopefully this helps. Remember, this thermostat will try to find ways to save you energy. As such, it will detect when you're not home and perhaps adjust the thermostat. Its job is to find those small savings which add up over time. If you really and truly don't want the learning capabilities, you'll probably have to find a more basic thermostat.
