Please can anybody help. I'm looking to switch my current honey cm921 programmer to the hive system hotwater and heating. We are on oil boiler Grant vortex Pro boiler and have separate immersion heater for water. I have taken off the current Cm900 honeywell wireless unit and found what you can see in picture. N and L I understand but there is then a connection from the live to port A with Port b having two wires in it brown and red. I am not stubed as to how this translates to the hive back box with is N L 1 2 3 4 I know that 2 and 4 is heating off and on that is it. Can anybody help. FYI I should point out the wireing you see is how we found it when we brought the house.