On Dec 4, 10:28 am, Clark wrote:
wrote in news:dcbbc519-df81-4578-9bd9-
:

I bought and installed one about a week ago and it's doing a great job
of controlling the furnace and temperature. But I discovered that
when I press the light bar on the left side of the devices, a quiet
and high pitched tone is emitted.

Has anyone else experienced this? Could it be result of a bad
component? Bad soldering? When I first opened the thermostat up I
wasn't terribly impressed w/ the workmanship of component mounting on
the circuit board.

The other question is of course - is this just normal and expected
operation of the device? I suppose I could call/email Hunter too!
But I do love talking to the "Internet."

Yup, the Hunter's appear to be cheaply made units. I have three of them and
they all hum just like all the other Indiglo devices I have. They also do
their jobs quite well so I'm not worried about the appearance.

Googling Indiglo and looking around a bit it turns out that the light is
generated by electroluminescence. The system requires AC and more than 100
volts. The electroluminescence light source is essentially an AC capicitor so
perhaps that is generating thenoise.


Interesting, thanks for the info!