I've always thought about doing this in my house, but there seemed to be a couple of sticking points. First, most frames actually hang off of the insert that backs the framed image, not the frame itself. This means that to hang a frame with nothing in it, you need to add a hook somewhere on the frame. Secondly, because thermostats are fairly thick, you need a substantial frame to around it, otherwise, you aren't really disguising the thermostat at all. Lastly, maybe this is just me, but I hate wasting a frame. If I buy a frame, I want to use all of it to hang something pretty, behind glass.
The ideal solution would have been to stumble upon a lovely vintage frame at a garage sale, missing its glass. Instead, while I was hunting for another project yesterday at Michaels, I found something pretty cool. Empty frames! Empty frames that are meant to hang empty! [Side note: Michael's website a huge pain. I tried to find any links, but nothing in all of the internet. So, just trust me, Michael's has them. I found them back by the custom framing desk.]
I measured out my thermostat and went back to grab a frame that would fit it. I'd bet good money that your thermostat is also roughly 4.25 x 6.25 inches, so a 5 x 7 inch frame will fit it nicely.
The frame actually had four different spots from which you could hang it. I originally decided to use the two side hooks so that it would self level. And also, the frame is fairly cheap and the hooks on the top/bottom were way off center.
I used painter's tape to try and gauge where I would need to place my nails for it to be level.
It failed miserably. It was so bad. My husband decided that it would just be easier to reposition the hooks on the back than try and calculate where we needed to place the nail for each crooked hook.
Once he moved it, easy peasy lemon squeezy.
Here's what it looked like before:
And here's the after: