Re: I go bang!
My heating system needs a six-way connection from controller/boiler to valves etc., all told. When I needed to replace a valve, I spent two hours very carefully tracing the cables, checking, double-checking, and re-checking. Glad I did, as the installer had used two standard 3-core mains cables, and was using the second earth wire to carry the (mains live) signal from the hot water thermostat to the controller. That cable has a big red flag on it now.
Biting the hand that feeds IT
