Hey all. I'm sorry my first post is asking for help. I recently bought the hive heating system. My set up is old.. my oil boiler is wired to a switch with just three wires. I only need hive to switch off and on and can only install it between the boiler and the plug. I have power going to the hive and it is ok. But I don't know how to form a circuit with the brown, blue and green wires to the boiler from hive. I've searched for hours with no success. I just need off and on! Any guidance would be life saving as my other half is cold.