Honeywell ST9420c to HIVE 2

[JLB90]

Hi,

I'm currently looking to change to a HIVE system. At present I have a Honeywell ST9420c timer with wireless thermostat and wireless cylinder stat. I believe that I have a Y plan system as I only have one 3 way port and a pump.

At present the Honeywell timer ST9420c has the following wires:

• Blue (neutral)
• Brown (live)
• Black (HW Off)
• Grey (HW On)
• Yellow/green (CH on) - bad practice to use earth, I've just found it like that

Boiler Model: Worcester Greenstar Ri

Questions:
1) Can I simply swap out the timer for the HIVE 2, even though I don't have a CH off?
2) Can I simply remove the wireless cylinder stat without replacing it?

Thanks for your help, I've attached a couple of pictures to help.

 

[JLB90]

Sorry forgot to attach the Hive wiring diagram.

 

[Wayne MInott]

Hi JLB90, how did you get on with this in the end? I'm about to do the exact same thing (once the Hive is delivered) so sharing your experience would be a great help. Many thanks