how can i fit an external programmer to my halstead ace high?

yes, you can just fit a new timeswitch. most boiler programmers have live + neutral (bit that keeps everything going round ;) and a live from boiler pcb through programmer and switched live out back to pcb.

you'd just connect to them and bypass old timer, just leaving it dead in situ and wire to new programmer/timeswitch. there are loads, siemens wireless programmable room stat is a canny buy from parts center

iain
October 2008