Great product however I had to purchase the extra floor sensor directly from WarmlyYours and pay the cost of shipping. Although it arrived quickly, I believe that if it is recommended that a back-up temp sensor should be installed, then these components should be available to purchase in the big box stores that sell the thermostats and floor heating systems.
Thank you for your feedback. You can find our back up sensor on homedepot.ca, amazon.ca and overstock.ca and coming soon -lowes.ca