Open Therm connecting wires

[ROBX3]

Hi,
I apologise if this has been asked before, but I cannot find any info regarding the pair of cables that connect the open therm device to the boiler - is there any specific type / size, do they just send a variable DC voltage or an actual signal and therefore have to be screened or not. I'm looking at installing a new system - mainly Honeywell products - and I am trying to get my head round all that needs to be done, but cannot find anything specific around these connecting cables.

Any advice appreciated.

Rob

[billytkid]

i used 2 core 240v cable, stuff you use to wire a single light in a bedroom hanging from the ceiling, this'll be fine.

It's low voltage. Also note there is no 'right' way round on the wiring, it sorts itself out

[Richard]

Screened control cable is my recommendation as OpenTherm is a data cable...

[Peter]

The instructions for the Honeywell bridge seem to suggest 0.5mm-0.8mm.