Perhaps use this virtual thermostat. You assign your Zen15 and temp sensor to the virtual thermostat and it will turn the Zen15 on and off and keep the temp at a set value. I have this set up in my shop office. Using a Zen15, I plug in a heater in winter and a Portable AC in summer.
You can make a rule to just turn the thermostat on and off or perhaps use the thermostat scheduler available.
