I promised an update regarding the Humidity sensors once I get it and have it installed.
Well, I received two sensors. One loose one and one premade with a temp sensor.
First I replaced the sensor in the indoor unit and after 24 hours outside, I started to receive the same results as the old sensor.
I then took down the outdoor unit and mounted it on a table making it easier to work with. Opened to unit and replaced the old temp/hum sensor with the new one. While at it, I also gave it a good cleaning, a 15-1 Spray and Forget solution work wonders in getting all that junk off, being careful not to get any on the sensors.
Fast forward 3 weeks. Both hum sensors now track within 1 to 5 degrees. It is very close at the lower values <60. Over 80, the outdoor unit reads 3 -5 higher, but that can be due to its location. The indoor unit is under my porch. In windy conditions, the readings are much closer. A fan might do the trick, problem is where to mount it
Here is a picture showing the difference, the new one on the left is covered by some type of thick paper towel material. Not sure what it is.
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Thanks to Ed, Ambient/Fine Offset, in providing the replacement parts. Happy again with my WS-1200