For multi-zone systems, the answer is a simple yes. IFTTT applets are available for Honeywell Evohome multi-zone heating systems.
For single-zone systems using Nest Learning Thermostat heating systems the answer is yes up to 31/08/19.
But as part of Google’s integration of Nest into the main Google company, new Nest customers after this date will sign up for a Google account rather than a Nest account. Google is also stopping the “Works with Nest” programme which IFTTT has been using to access the smart features of the thermometer and replacing it with “Works with Google Assistant”.
Existing IFTTT applets will continue to work for existing Nest customers. However it is unclear whether new customers will find it easy to use the existing IFTTT applets and also when IFTTT will be able to provide replacement applets using the “Works with Google Assistant” interface.
As we find out more, we will let you know.