*PLUMBERSSTOCK EXPERT* responded:
We appreciate your interest in our Tekmar 510 Programmable Thermostat Heat. “E02” Error means that there are no active sensors selected on the thermostat. To correct this, you must turn the internal sensor on or set at least one auxiliary sensor - either INDR or SLAB. Once corrected, just press any button to clear the error message. For more information on this product, feel free to check the specification sheets. If you need further assistance, don’t hesitate to contact our customer support at 435-868-4020. You may also email us at email@example.com anytime. Thank you for shopping with plumbersstock.com – the perfect place to find high-quality products at low, low prices!