Algo-Energy warrants that the device is delivered free from defects.  As per the manual, this Venstar product is warranted to be free from defects in material and workmanship. If it appears within one year from the date of original installation, whether or not actual use begins on that date, that the product does not meet this warranty, a new or remanufactured part, at the manufacturer’s sole option to replace any defective part, will be provided without charge for the part itself provided the defective part is returned to the distributor through a qualified servicing dealer.  

Additional terms are described on the last page of the manual, which is on-line at: https://files.venstar.com/thermostats/colortouch/documents/T5800_manual_rev7.pdf