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Tony Hwang Tony Hwang is offline
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Default 'Electronic' thermostat. RFI (For info).

terry wrote:
We have just replaced a 40 year old 'analog' thermostat that we felt
was sticking or not reacting properly, with a simple electronic one.

The new thermostat has a capacity of 2000 watts (in this case a single
1.2 or 1.5 k.watt heater in one 10' by 13' bedroom) and seems to
work well enough.

However it creates all kinds of RFI (Radio Freq. Interference) only
faintly apparent on a radio some 30 feet away tuned to the 640
kilohertz station we listen to most o the time. But 'roaring' when not
on any station! Haven't done any tests at other frequencies yet. e.g.
FM.

The thermostat appears to cut in an out at frequent intervals, not the
occasional swift 'snap action' of the original one. Then while 'on' it
produces a signal with what seems to be a 60 hertz buzz. While
installing it looked to be some sort of triac mounted on a heat sink.
Seems to a single pole device whereas the original was double pole; or
single pole with a second pole for turning it off in the other 230
volt leg?

Very surprised our variuos regulatory authorities, in USA the FCC and
the similar authority in say, Canada, allow these interfering devices
to be sold? But by same token we have a non rechargeable shaver that
emits a god awful racket even when just plugged in. Fortunately it
only has short couple of foot range of interference!

Will probably plan to remove the electronic thermostat; seem to recall
have a spare 'oldie' thermostat somewhere. BTW, the only repairs we
have had to our electric heating since 1970 has been three
thermostats, one of which was changed for reasons of 'decor'; and one
20 amp DP circuit breaker. Can't complain about that in comparison to
say oil, or gas (not available here), fired equipment .

Hi,
Brand name of the 'stat?
Use some Ferrite cores.