Anybody know what size heat resistant flex I should use to add a Sunvic TLX 2259 room thermostat to my Vaillant TurboMax 837e combi boiler?
I want to use the full 4 core set up (live send / live return / neutral anticipator / earth).
ie .75mm2 / 1.00mm2 / 1.5mm2 ?
To be safe I have...
