ok - I have the same boiler, but with a digital, rather than an analogue timer - I'm assuming the connections are the same (the wire colours are)
white/red wire - remove existing double black wire from back of timed/summer/constant switch, fit double connector onto terminal, connect red/white wire & refit original double black wire.
blue wire - connect to bottom terminal marked 'N' on main terminal strip ( marked NL123N)
white wire - connect to terminal '1' on main terminal strip.
Red/black - connect to spare terminal on back of timed/summer/constant switch.
usual disclaimers apply (not my fault if it doesn't work or blows up, basically
) but I hope that makes sense.
