Where to start - Checking the status of two or more "things" before triggering an action

[JDRoberts]

I agree with the others that Rule Machine will probably be your best choice, but if you want an overview of the various options, this should help:

A Short Intro to Scheduling/Device Control/Rules in SmartThings Classic

(March 2018: All of the following applies only to the SmartThings Classic app. If you purchased your hub after March 1, 2018 and are using the new “SmartThings (Samsung Connect)” app, creating rules works differently.) You’ve got your hub. You’ve got some devices. Now how do you schedule what happens when? SmartThings doesn’t have a rules engine/scheduler, so there’s no one tutorial for how to do this. But it’s an open platform, and there are about 12 different ways to set up various kinds of schedules. Some require custom code, some don’t. A “scheduler” in this context is anything that causes a networked device to perform an action, even if it’s just to toggle on or off immediately. (Network engineering definition, forgive me. ) (Note: as of April 2017, the original author of …

Also, since you mentioned that you have an iPhone, there is a third party app (iPhone only) that costs about $8 (+ $2 if you also want IBeacon support) that works very well if you want an if A while B then C. Not as powerful as Rule Machine (which is free), but very easy to use and a nice graphical interface. I like it a lot.

http://smartrulesapp.com