Would you be open to the idea of removing the circuit breaker and place a copper bar in its place? It may improve things sonically. You may ask if this will render the circuit unprotected and create a hazard. Well, by grounding to the radiator it would have the same effect - even if you still have the third plug connected to the outlet. Any fault current (an abnormal condition) may flow to the radiator instead of back to the panel and the circuit breaker may not sense anything wrong and will happily keep supplying the juice. There's a method of madness to all those electrical codes.
It cannot be over-emphasized: if you're not fluent in electrical safety, keep a respectable distance and always ask a professional for assistance.
It cannot be over-emphasized: if you're not fluent in electrical safety, keep a respectable distance and always ask a professional for assistance.