we have a baxi bermuda back boiler central heating system that is twenty years old now. we have replaced the pump, and now want to replace the programmer, cylinder thermostat, three port valve and room thermostat with a horstmann package to replace the ageing honeywell system. i need an easy to follow wiring diagram so that i can start from scratch. also can anybody tell me why my boiler and pump start up even when the programmer is off?

jack jones, November 2006

DONT DO IT, HONEYWELL COMPONENTS ARE BY FAR THE MOST RELIABLE, AS FOR IT COMING ON WHEN SWITCHED OFF, MOST LIKELY A STICKING SWITCH IN THE 3 PORT HEAD.
IF YOU CHOOSE TO CHANGE IT ALL, THE PACKAGE WILL HAVE A FULL WIRING DIAGRAM.

BG MIKE, November 2006