LP241 Programmer

[fabweldcad1]

Had a new kitchen fitted when joiner was removing tiles he broke the wallplate of the programmer i numbered wires in terminals got a replacement wallplate fitted wires as before but there was a blue wire at back of wallplate which looked if it had been connected to a terminal. The wiring is as follows N has 2xblack, L has 2xred, 1 has 1xred, 2 has no wire, 3 has 1xyellow, and terminal 4 has a blue wire. There are also 2xred wires in a block and a black and yellow wire in another block the small switch in the back of the programmer is set to P. Hot water is fine but central heating begins and then stops. Is this blue wire the problem.