Hello,
Can someone tell me if it's okay to mount a digital thermostat vertical or sideways so that it can fit inside of an existing lockbox cover? I know you can't with a mercury one.
Thanks,
Tony

The wall plate is not required to be mounted level. The wall plate is installed level for appearances only with the digital thermostats.

Since there are no mercury switches in the new digital thermostats you can mount them any way you want. I will add this fact. Many digital thermostats have openings in the mounting plate both top and bottom. This is to allow room air to circulate and activate the thermistor/resistor for the sensing of temperature.

So hook it up sideways. It should work OK.