In message , Chris R. Lee
writes
Hope you used a special transformer. A dimmer gives pulses of mains voltage
that are a lethal as the straight mains.

And why is this a problem?

AFAIK heating cables are mains voltage anyway - I have one in home made
propagator controlled by a rod thermostat control no transformer AFAIK
--
Chris French and Helen Johnson, Leeds
urg Suppliers and References FAQ:
http://www.familyfrench.co.uk/garden/urgfaq/index.html