ZTS-110 - Z-Wave Smart Thermostat

I installed this thermostat to be controlled by the Wink hub. So I’ve broken the review into two parts: a) The thermostat itself; and b) Using it with the  Wink hub .The ZTS-110 is inexpensive for the features it offers. It can be powered by 4 “AA” batteries, or via a 24V common wire from the air handler unit (AHU). When powered by the AHU, it is in “always on” mode, where it responds instantaneously to commands from the z-wave controller and also acts as a relay in the z-wave mesh network. When powered by batteries, there is a 2-10 second delay in its response to commands from the z-wave controller, and it doesn’t act as a z-wave relay (FLIRS mode). FLIRS mode is identical to how other battery-powered z-wave devices function, such as z-wave locks and deadbolts. The method by which it is powered matters during initial thermostat setup. If powered by a 24V common wire when it is paired to the z-wave controller, it will continue to be in “always on” mode, even if it is switched to being powered solely by batteries later on. Similarly, an initial z-wave pairing performed when it is powered by batteries will keep the thermostat in FLIRS mode even if it is later powered by a 24V common wire from the AHU. This initial setup can be changed only if the thermostat is reset, unpaired from the z-wave controller, and then re-provisioned. Thus, it is best practice to power the thermostat via the desired method (battery or 24V common) before provisioning it to the z-wave controller.The ZTS-110 is equipped to control the HVAC equipment found in the majority of North American homes; specifically, 1 or 2 Heat stages and a single Cool stage, or a heat pump. The AHU blower fan can be controlled independently or automatically, i.e. turning on/off with the Heat/Cool stages. This thermostat doesn’t support variable speed blowers or variable speed compressors; an important consideration if you are planning to upgrade HVAC equipment in the near future.The thermostat can be used in “easy” and “advanced” modes. In easy mode, parameters that control thermostat function, such as schedules etc., are set via the z-wave controller (i.e. the computer/smartphone application you use to interact with the z-wave controller). In advanced mode, schedules and other thermostat functions can be set directly at the thermostat. It is possible to switch between easy and advanced modes without resetting the thermostat. There are two useful parameters that can be set using advanced mode, which I cannot set in easy mode using the Wink hub. Specifically, the “Swing” + “Differential”, and “Advanced Recovery”. The differential setting only comes into play with 2 heat stages - not applicable in my installation. The swing determines with temperature difference between the set-point temperature and the ambient temperature when the thermostat turns on and off. For example, if the swing is set at 1 degree F, and the set-point is 75F, then in cool mode, the thermostat would turn the compressor on at 76F and turn it off at 74F. The swing and differential can be adjusted from 0.5-4 degrees F, and by default are both set at 2 degrees F. Advanced recovery permits the thermostat to control heating/cooling to reach the desired set-point temperature at the desired time. For example, if set-point at 6 PM is 75F, and the ambient temperature at 5:30 PM is 78F, cooling will be turned on prior to 6 PM, such that the ambient reaches 75F at 6 PM. Both these features are commonly found in mid-range non-connected thermostats that are priced similarly to the ZTS-110. i.e ($40-80), so it is pleasant surprise that have been incorporated in this entry-level connected z-wave thermostat. The ZTS-110 also has short-cycle startup protection, meaning the compressor or heat pump will not be turned on until at least 3 minutes have passed since the last run cycle. This time, 3 minutes, is not user changeable. Also, it isn’t possible to specify a minimum compressor run-time; the latter being useful if the central AC unit is oversized. These features are available in connected thermostats like the  ecobee Smart Si  and  ecobee3  that are priced significantly higher than the ZTS-110.With a suitable z-wave controller, additional configuration options can be set, including:a) The temperature difference between the last two ambient temperature readings that automatically triggers a report to the z-wave controller (by default 4 degrees F); and b) the automatic report time interval (by default 1 hour). Both of these can be changed (or completely disabled) to increase battery life.b) The sensor temperature calibration offset; however, I found the sensor to be calibrated just fine in the unit I received.What about using this ZTS-110 with the Wink hub and  Wink app ? The thermostat can be provisioned as a generic z-wave thermostat to the Wink hub. Through the Wink app, the thermostat can be set to be “off”, “heat only”, “cool only” or “auto”. In auto mode, the thermostat switches between heating/cooling based on the difference between the heating/cooling set-points and the ambient temperature. By default, the thermostat reports the current ambient temperature back to the Wink hub (and thus Wink app), when it is in FLIRS mode (battery powered), and presumably much more frequently when continuously powered. Schedules can be set using the Wink app, and Wink app robots and shortcuts can be used to control the thermostat, for eg. through geofencing or IFTTT. Also, when used with IFTTT, it is possible to control the thermostat based on changes in the current weather. Thermostat features that cannot currently be read/set using the Wink hub are: 1) filter life and change time; 2) the auto report time; and 3) sensor calibration. Because I am using the thermostat in FLIRS mode (i.e. battery powered), there is a 6-10 second delay between opening the app and getting current readings from the thermostat - when I force an update. There is a similar delay between changing temperatures in the app and the temperature changing on the thermostat. In my opinion, this short delay doesn’t practically impact thermostat function.In summary, I think this is an excellent thermostat that is priced lower than many non-connected thermostats. Perttinently, when used with a z-wave controller, it permits advanced control of the thermostat - reducing energy use and increasing convenience.

I installed this thermostat in a vacation home a few weeks ago. The installation was simple and it connected to my Smartthings hub (V2) with ease. This unit operates via battery power of via power line, if so equipped in the in-wall wiring. Unfortunately, my only choice was to use the batteries, as the wiring in my home required it. The manual indicates that when the unit is on battery power, the communication with the hub is far less frequent to conserve battery power.As a regular thermostat, it is a fine product. It has two modes: 'Easy' and 'Programmable'. With easy mode, one simply raises or lower the temperature on the display and heating/cooling follows as normal. Programmable mode allows one to set temps at particular times each day of the week. It works just like any other programmable tstat. The default is 'Easy' mode and that is what I am using.The downside of this unit comes from it's ability to interact well with my Smartthings hub (Z-Wave), at least while on battery power. I am at the mercy of the unit as to when it decides to 'share' the information with the hub. It appears to happen less than once per day, but I have not determined any set pattern. The problem this creates is that I cannot poll the unit at any time to determine its status. For example, If it is cold outside and a window is open, I cannot determine if the unit is heating the home or not in order to control it. (All other 'things' allow me to see the status their status immediately when asked, including battery operated temperature and humidity sensors).I will assume that this unit will be better suited for polling if it is running on wall power and not battery power and would recommend this unit wall power is available. However, I will be seeking a replacement as this is not suitable for monitoring while on battery power.Update: 12/29/2015. Based on additional info and tips from others on this thread - I changed my rating from 3 stars to 4 as the unit does work, they have just chosen to only support Vera fully (per the detailed instructions on the Remotec web site. Now, if Remotic would publish the app to work with SmartThings, I will up my rating further.

Poor quality. Unstable. No available data to build a proper handler with Smartthings (a handler is like a driver for your computer devices, like a webcam: you may have a great webcam, but without proper driver it won't work reliably). Just cheap bad stuff.Also: unreliable temperature readings.