Simple Digital Room Thermostat Volt Free Wi-Fi Minimalist White Square Wall Mount App Control Remote Access Graphical LCD Battery Powered 2.4E+2 volts HVAC Control Thermostat

This thermostat is rated to be differential 0.5k, but in reality it is at minimum 1.5k to 2k !! That's a huge, way too huge difference. When you set it to 22 degree, it will stop heating at 23 degree and start heating at around 21.5 degree. If it was 0.5k then it should start heating at 21.75 degree and stop at 22.25 degree, but that's far from the truth. It is also built very cheap and falls apart easily by touching it. I have a Siemens rated to be having 1k differential and it works much better. Wanted to upgrade to 0.5k differential, but no luck. The Siemens start heating at 21.5 degree and stop heating at 22.5 degree, which is accurate for 1k differential. Avoid this chinese useless junk and take something with better quality. We are not that rich to constantly buy cheap products and throw them away.

I have bought and returned several thermostats as each one proved inadequate in their key function namely - accurate control of temperature. None came remotely close to my original Honeywell piece of kit. But this Celect model fits the bill really well operating within 1 degree of the reading of my mercury thermometer. It doesn't feel as solidly built as the Honeywell it replaced,. I am hopeful this will not matter in the long run.

it is annoying to set up. However after you the initial set up it works good. Have it now for 2 years

This DRT1 thermostat does what it's designed to do. It keeps the house temperature within a narrower upper and lower range than the old analogue Honeywell it replaced. If, for example, you set the temperature at 18.5C it switches on the central heating as soon as the temperature drops half a degree below that to 18.0C, and switches off when the temperature gets to 19.0C (after swtiching off, the house temperature may continue to rise a bit more as the radiators will still be hot for a time). The only slight frustration was that the terminal block is slightly obscured by the outer casing, so it's fiddly inserting the wires (best to insert the wires before you screw the thermostat to the wall). You will also need a very small crosshead screwdriver (rather than a flat head one) to secure the wires in the block. Incidentally, if you are replacing a Honeywell analogue, as I did, you connect the live wire to COM on the DRT1 terminal block and the switched live (the one that goes live when you turn the thermostat up) to NO on the block. You don't need the neutral or earth wires which need to be secured in a separate terminal block you will need to get. There is room to tuck this into the casing. The DRT works well.

From the outset I found the display hard to read. In the finale it died 1/3/2020, about 80 days after purchase. The display shows the demand temperature but does not seem to know the actual temp. As a result it sits there doing nothing. Resetting it does nothing. Buy cheap buy twice.

This is not a Wi-Fi compatable unit

Displays half degrees and responds to within a degree so the room temperature can be more closely controlled than with the old style mechanical thermostats. The wireless version costs only slightly more, obviously saves on wiring, displays even tenths of a degree. Powered by two AA batteries. The controlling signal is just a short pulse, so the battery last. Brilliant.

Simple to install, does take a lot longer than the estimated 8 seconds to respond to the change of temperature, but this is not critical. One small snag, unless the wiring comes through the back of the unit, cupboard whatever, a small section of the frame has to be removed. Other than this, a simple sturdy and reasonably priced thermostat.