Baxi TXW1AC User And Installation Manual page 44

FIXING THE WIRED CONTROL
Use a flathead screw driver to pry the bottom groove of the wire controller lightly
(too much force would damage circuit board), pry rotationally to open the back
cover.
As shown in Fig.3, fix φ4 * 20mm screws provided together with the back cover
on 8 6 box, then pass lead wires through the back cover.
After connecting the connecting wire to the main body of the wire controller,
install main body part according to the following steps:
1).Push the upper part of main body into the clip.
2).Use the force of inclined top to install the lower part of main body (horizontal
installation is prohibited, which is easy to damage the structural slot).