Avalon Firestyles 864 See-Thru GS2 Installation - Manual (Page 70)

70 Optional Equipment
(for qualified installers only)
© Travis Industries 4141208 100-01404
6. Pull the base IFC forward to access the wiring (it is held in place with Velcro).
7. Disconnect the comfort control wires and battery backup wires from the battery holder.