On Feb 4, 11:39*am, "James Sweet" wrote:

Sounded like you already had it figured out. Replace the triac ...
and give it a go.

Not going to work, I suspect. The 'triac' in a light dimmer is
actually a 'quadrac', which has a builtin trigger device, and isn't
readily available in larger sizes. Phase control like
in a light dimmer makes for non-flickering illumination.

But, you don't need any of that; the problem is just that
long duty wears out the switch contacts, not that the
few-seconds-on/few-seconds-off is a bad match for the
heater interface. Your options are many: wire the
replacement to a solid-state relay instead of directly to
the load, or use an industrial-grade furnace controller
(put a thermocouple sensor in your cauldron).

I have some mercury relays in my junk box that would
give decades of service without a problem. Even simple
contactor relays, if you use appropriate snubbers (I like
surge-protector varistors for this duty) will last a long time
compared to a consumer stove control.