I have written several recipes to control our NEST thermostat and sometimes they work, but mostly they dont. The channel between NEST and IFTTT constantly fails and no one knows why. IFTTT support blames NEST and of course NEST support blames IFTTT.
When you Email either support group it can take 3 to 4 days to get an answer especially from IFTTT support and they dont offer a phone number; they dont want to talk to us. So you wait and wait and nothing works in the meantime.
Go ahead and use it if you want to bang your head on your desk.
MGFerris about IFTTT - Automate work and home, v2.7.2