Horseman TIARA and Honeywell Remote Stat to Hive Single Channel

[goldenballs999]

Hi folks,

I've searched the forum and am still none the wiser. I have a gas combi boiler and this Horstmann TIARA and Honeywell Remote Thermostat that I want to swap out for a hive single channel system. I have no stored water cylinder.
I also now have no remote room thermostat either as we took it off the wall for the renovation and the other half threw it out, therefore need to get this swapped out sooner rather then later as the boost function is the only way of getting the heating to work!
All help appreciated people, TIA

 

[RandomGrinch]

The cable furthest back appears to be the one connected to the boiler...

The cable with the grey wire appears to go to the R6660D.

To connect the Hive (assuming single channel), use the 'boiler cable'
Connect the Blue wire to N
Brown wire to L
Black wire to terminal 3
Green/Yellow to earth terminal
Add an additional short link wire between L and terminal 1

If that works, the R6660D cable can be completely removed.

 

[goldenballs999]

The cable furthest back appears to be the one connected to the boiler...

View attachment 353739

The cable with the grey wire appears to go to the R6660D.

To connect the Hive (assuming single channel), use the 'boiler cable'
Connect the Blue wire to N
Brown wire to L
Black wire to terminal 3
Green/Yellow to earth terminal
Add an additional short link wire between L and terminal 1

If that works, the R6660D cable can be completely removed.

Absolute legend! All up and running, thank you!