I noticied this winter my heater was not turning on when the temps dropped below 5oC, and even down to -7oC when I confirmed there was a problem because my battery was not reporting the usual 0.8 amp draw when the heater turns on (more about my heater power system here
https://www.wxforum.net/index.php?topic=43135.msg448456)
My device is from the Kickstarter program, so its almost 3 years old but I contacted Ecowitt anyways.
The heater system is quite simple, and based on a thermostated switch. This switch, which is normally open, if shorted, will turn on the heater like so (see red wire):
[ You are not allowed to view attachments ]
and you can see the heater plate warm up (actually almost went to 50oC)
[ You are not allowed to view attachments ]
Ecowitt sent me the part, and i removed the old one and soldered in the new one. The part is "JUC31F- 0oC H" more about the part here:
https://www.calcoelectric.com/images/pdfs_thermostats/juc31.pdfyou can see its a simple bimetallic snap-click thermostat mechanism. Supposedly, its rated to 100,000 cycles at 5VDC. I have not done the math, but this thing works hard in cold climates, it turns on and off, probabably every few minutes (depending on the temp), for 3 to 5 months of the year, here.
Long story shory, after I soldered in the new part, here:
[ You are not allowed to view attachments ]
my heater is now back to being functional.
[ You are not allowed to view attachments ]
Cheers