We've got a new dual fuel heated towel rail that we've been happily using on the electrical setting. I want to incorporate it into the main gas central heating system but I'm not sure what I'm supposed to do with the valves.
As you can see in the picture there's a valve which is connected to the electrical socket and another one that isn't. I remember the plumber telling me what to do to change the setting but I can't remember and I'm worried about damaging something. Should they both be open/closed or one open and one closed. Any help gratefully received!