In article ,
fred writes:
It's nice to derate contacts by quite a bit to extend life but there's
really no need to do overboard. 5A vs the nominal 4.35A is a little less
margin than I'd like but this sounds like a Horstmann/Tower programmable
stat so I wouldn't be expecting 20 years out of it in any case.

Over 20 years ago, I bought a bathroom fan heater (Dimplex).
Although it was set down to just 1kW (could be set to 1kW
or 2kW at installation time), the integral pull cord switch
burned out in about 3 months. I cleaned up the switch and
fitted a small contactor into a cavity inside the heater
which was for a shaver isolating transformer in a different
heater model, with the switch operating just the contactor.
It's been running fine ever since. Apart from the inadequate
switch, it was very well built.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]