On 2/5/2018 8:56 AM, TimR wrote:
On Sunday, February 4, 2018 at 6:00:49 PM UTC-5, dpb wrote:
On 2/4/2018 3:29 PM, Cindy Hamilton wrote:
...

I've never understood the "precision" argument. Does it matter whether
it's 70, 71, or 72 F ? I suppose 31, 32, and 33 F are more significant.
...

Well, there's the same question around 212, too, from that standpoint...

I ran into a minor instance here just recently -- fixed up a monitoring
system in the well house to alert me if the temperature drops that
indicates I need to go relight the gas heater (occasionally the high KS
wind will manage to blow out the pilot). I used a cute little $6
digital thermostat module in "heat" mode to turn on an LED in the window
I can see if temp drops below setpoint.


So when it calls for heat it closes a contact?

Yeah, being as it is designed to be a thermostat it has a
builtin-contact onboard. I debated which way to go; could use a green
LED and have it lit when OK but decided to go the red and be normally
off and turn it on when indicated a problem. I wasn't sure at first but
the LED is bright enough it's easily visible in the wellhouse window
when on even during middle of the day. I haven't put it on a battery or
used a UPS at the moment so if we're out of power I still have to check,
but it covers the bulk of the time...

Ingenious.

Um, what's the dead band set to?

I've left it at default of 2 C; it's adjustable, too.

I was going to comment that had to compute where wanted setpoint to
start for the user interface in C; at the price point you can't expect
much documentation but I just presumed when ordering since it's all
digital there would be a F/C option in setup--turns out there's not, at
least in this one. I'm sure they must be out there...


A link
https://www.ebay.com/itm/W1209-12V-50-110-C-Digital-Thermostat-Temperature-Control-Switch-Sensor-Module-/192112054053


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