TR7 thermostat housing

[Allen Nugent <A.Nugent@unsw.edu.au>]

Dear Listers,

All this about thermostats reminded me that I can't get the top off mine. It
has a large (approx. 1" diameter) hex-head with a wide (3-4 mm) slot across
the middle, and seems to be made out of brass, as it deforms when I try to
turn it with a spanner.

Any body know a trick for this one?

Allen Nugent
Graduate School of Biomedical Engineering
University of New South Wales
Sydney  2052  Australia