*PLUMBERSSTOCK EXPERT* responded:
Good day! We appreciate you asking about our Filtrete 3M30 Touch-Screen Programmable Thermostat. To replace the battery, open the bottom cover of your unit to access the battery compartment. You will need to install 3 AA alkaline batteries by followingthe marked polarity in the battery compartment. Put the lower battery in negative end first againstthe spring, then push the positive end in. You will then need to insert the last two batteries in the same manner. Page 8 of this Install Guide shows a drawing on where to put each battery. Should you have further questions, please let us know. Thank you for shopping with plumbersstock.com – the perfect site to find high-quality products at low, low prices!