Thanks for the quick reply, it’s dark now so I’ll have a look tomorrow. What I assume you mean by the deltabell is out the back on the far end of the garage. I’ve always assumed it was a dummy and we’ve never heard it in the house over all the other din.
I‘m attaching a couple of shots of my control panel which was installed a few years back by a small local business which now seems impossible to contact.
I imagine this box must be pretty generic but I haven’t been able to see any branding. I’ve previously been able to replace the batteries in...