On Sat, 06 Dec 2008 16:35:18 +0000, Andy Champ wrote:

(How? This has to work without electric from the temperature of
the store) it takes a while for the significant amount of heat in the
firebox and mass of the stove to dissipate. Oh and a lump of ash could
stop the vent shutting properly, single point of failure...

They work by having a damn great bimetallic strip with a flat plate on
the end. When hot, it bends the strip so the plate covers the air
inlet. Seen them on (IIRC) Rayburns.

Fine but that only regulates the device from the temperature of the device
not that of the store. It also doesn't shut the device down (as if off)
and you still have the problem of lots of residual heat.

--
Cheers
Dave.