Calling for heat from wet underfloor heater to combi boiler

[kidkal]

Hello,

I have combi boiler Heatline Capriz 2 28c running hot water and radiators on the ground floor. I have underfloor heating system on the top floor with two zones upstairs, using Heatmiser UH4 controller. The underfloor heater currently works when combi boiler timer (or heating switch) is on AND the thermostat and programmed timer is on for the underfloor zones. I would like to have the underfloor system call for heat independently from the builtin combi bloiler timer. How do I go about doing this?

On the Heatline Capriz manual, there are connections for "Room thermostat", "External thermostat" and "Bus" or is there a way to connect up the Heatmiser controller to this or is there a way to override the internal boiler timer?

Thanks.

 

[kidkal]

Here are the wiring diagrams for the boiler and UFH controller. I would appreciate any help on this.

 

[ianmcd]

set the boiler timer to constantly on and the thermostats will take over

 

[kidkal]

If I do that, then I will need have another timer/thermostat for the radiators?

Then for the "Boiler Enable", do I connect this to the "RT" connections on the boiler?

What about this zone 4 yes/no switch? should that be on "No"?

 

[kidkal]

Ah maybe I understand better now.

The radiator does have a solenoid valve connected. The differences from my wiring to the the manual diagram are:
1) I don't have a "radiator stat" connected
2) "Heat Enable" connector has a "live" mains wire connected to it
3) Zone 4 control switch is set to "Yes"

Diagram of current wiring:

Presumably, that's to compensate for the lack of radiator stat (or I'm don't know what that live connection is for)?

If I do the following, do you think it will work?
1) get one of those Neostat from Heatmiser (would probably need to be wireless one) and connect to the Zone 4 controller for the radiator
2) switch the zone 4 control to "No"
2) remove the mains live wire from "Heat Enable"
3) connect the "Heat Enable" to "Room Thermostat" on the combi boiler

Any other advice, suggestions before I make the purchase? Thanks!