We have 20 in stock.
The most common cause of HVAC circuit board failure is damage to the electronics module as a result of poorly conditioned voltage. Plug-in transient, surge, lightning, amp spike protection for 24V systems. To use, plug the system's 24VAC transformer output leads onto the PRO-24's line side wires (the side with the inline fuse). Plug the PRO-24's load side wires where the transformer's leads used to go. Connect green wire terminal to a secure ground point. Insert proper fuse / place sticker nearby. Enjoy continuous protection. (Full instructions in package.)