can you change the c/h temp sensor with out draining the system

morris20, March 2009

power off first!!!

....., March 2009

ch sensor. isolate flow and return under boiler, using drain screw (white knob right hand side bottom behind timer) drain boiler only. leave drain off open, slowly undo sensor checking for water (shouldnt be) and swap. nip up, close drain off, open flow and return and top up pressure to around 1 1/4 bar.

....., March 2009