Removing old Honeywell Thermostat... Advice please

prettygoodjones

Hello. I have an old Honeywell Thermostat in the hallway that was linked to a back-boiler for central heating in my house which was removed when we moved in. We now have a new combi boiler with a wireless thermostat.

So regarding the old Honeywell Thermostat... Can I just put the three-phase cable that goes to it in a junction box? There is a red, yellow, blue and earth.

Obviously it is not connected to a boiler, but I can't be certain that it's not part of the downstairs lighting circuit or something.

Thanks in advance.

Paul