On Tue, 11 Mar 2008 20:37:45 +0000, Owain wrote:

A mains powered firebell and remove the gong?

Still very loud, I just want something you would be aware of rather than
having your attention drawn to it. It's to wire across the "overheat" stat
on a 38kW floor standing cast iron oil boiler. It trips fairly often due
to being oversized for the load on it most of the time. But not oversize
for the load that could be on it...

Even a vehicle reversing alarm would be a bit loud but is an interesting
thought. It's that sort of beep beep beep I'm after, just a lot quieter.

--
Cheers
Dave.