Digital Non-Programmable Thermostat,1H/1C, T21STK-0 Digital Heat/Cool Pump Thermostats,24 Volt Single Stage Thermostat for Room White

Outside of the instructions being a bit confusing on the wiring, but was figured out fairly easy even for a homeowner like myself. So far has operated well and is easy to operate. The settings are easy to understand and once its done there's no worries.

re: T21STK-0 bought aug 2018.Pros:Large, easy-read display with current and set point temp display at same timeEasy installPrinted manual was thorough and in decent EnglishOperates as one would expect with cycle rate set to SL (slow)Fair priceCons:Manual not available online or anywhereThe inside of the drop-down cover ought to have config instuction stickered thereThe picture is wrong: the saswell logo on unit received is grey, not red as in picUnknown:battery longevity [update 2/9/2019 battery going strong for 6 months now][update 8/13/2019 battery going strong for 12 months now, so the thermostat does not drain batteries unduly][update 12/2/2019: replaced batteries today. So alkaline batteries last about 16 months in this thermostat]

I bought two of these and they do work correctly. In the menu you can change it for a heat pump however it does not supply power to the compressor (y yellow wire). It only supplies power to the white (w) which would be your back up. I’ve tried every combination to get it to work. I bought two of these in the summertime so I had no idea until now that the heat pump future did not work and cannot return it. Cheap junk

I am pleased with the Quality and all the functions of this thermostat. It was a very good price and easy to use.

Used this to replace a NEW digital Honeywell that was grossly inaccurate. Mounting holes were the same so that was convenient. No batteries are required, utilizes the (C) common wire which is a big plus. But definitely save the manual (can also dl it from this product page).Default settings are terrible. For heating and cooling the default is (FA) fast cycling rate with is 0.5°F/C which would make your system turn ON/OFF constantly. Best to change that to (SL) slow, 1.5°F/C Δ which is far more practical. Backlit display is nice but can only read it if looking directly at it or from above. Digits become invisible if looked at from even slightly below making placement on the wall rather important, especially for shorter people. There is also a internal slide switch, for most people will need to be changed over from ELEC (default / Heat Pump) to GAS.So not as plug and play and these should be but still more satisfied with this than the name brand units.

Easy to read and control. So far so good after 2 months of use. I highly recommend!

Unit does not like to stay in place on the base that it clicks into. It falls off it you bump it hard.The manual is unavailable online. Saswell's website has a page for this thermostat, and a download button, but when you click the button, it wants you to log in. There is no way I can find to create a login and password.

I installed it and is working great no problem for now it doing a job of controlling the temperature