Product review (1 stars): Accuracy, stability, and consistency leave something to be desired.
*UPDATE* 2018/06/22 - Dropped to 1 star. The remote sensor reading is even less stable than it initially appeared. It might be +3 degrees over actual temp in the evening, and anywhere from correct to -1 or -2 degrees in the morning. It seems like right about 70 F it is pretty close (+/- 1 degree), at 75 it seems to be +2-3, and in the mid-sixties it the readings seems to drop into the negative - at 65 F it reads 66-63, and at 60 it reads 58-61.

Also, I discovered that if one of the sensors goes completely off line the console will never tell you. I took one of the sensors with me for some additional testing, and the console still shows 67 for that sensor.

----- Original Review -----

TLDR: After reading a number of reviews I went ahead and purchased this set to replace a very old system that finally died. I thought I'd give it a whirl since I wasn't really looking for research level temperature tracking, and the price was good. But.....I'll be returning it shortly.

* Pros *

Reason to buy this #1: Setup was fast (+ 1/2 star for this)

Set the channel selector on each sensor, put the batteries in the sensors, then put the batteries in the display. 60 seconds and you're running.

Reason to buy this #2: Price (and + 1/2 star for this)

But remember you get what you pay for. So keep that in mind.

* Cons *
Issue 1: Inaccurate when compared to each other and a calibrated Temp/RH gauge.

(Side note: I wasn't expecting lab grade accuracy, and I expected them to be somewhat off. The temperature sensor that is usually used in household consumer grade sensors costs a few cents in bulk and generally has an accuracy of +/- 2 F around room temperature (60-70 F) with accuracy degrading as you move towards warmer or colder extremes.)

That said....

I set all three sensors and the base station on my desk right next to each other, leaving about an inch for airflow and gave them 10 minutes to stabilize. The two sensors with the digital display both showed the same temp and RH, but the outdoor unit was higher by two to three degrees and showed 8% higher RH. I didn't expect much from the RH (no electronic RH sensor is going to truly be accurate), but I didn't expect an 8% variation. The base station display showed a higher temp and lower RH than the display sensors.

I then placed a a calibrated commercial Fluke RH and Temperature gauge that we use for testing our HVAC systems right in the middle of the sensors and display. The actual RH was 47%. The small displays showed 54%, the outdoor showed 58%, and the base showed 57%. Not too bad overall for dry electronic RH sensors - well within expected values for consumer grade gear.

The temperature was slightly more off. Fluke gauge showed 71.2 F. The small displays showed 73-74 F, outdoor showed 74-75 F, and the display showed 75. The sensors fluctuated a little bit.

Issue 2: Sensors not stable over time

I "calibrated" the console (adjusted the displayed values to match the correct temperature), took them home, and set sensors next to our Honeywell digital HVAC thermostats in each room, and placed the console next to the display console from our old system. Displayed values were high by three degrees. So either all of our HVAC thermostats, and our old console display are low by the same amounts or something else is going on. I reset the "calibration" on the display (pulled the batteries and reset the display) and then "calibrated" it again so that the displayed base station numbers matched what our existing displays showed. This morning they didn't match. Now the remotes displayed temperatures lower than our HVAC, and the Acurite console was higher than our old console.

So not only were they off by comparison, the amount by which they were off changed over time.

On a side note, "calibrating" only changes the value displayed on the console. So if the remote sensor is off by 3, the remote will ALWAYS show the incorrect value. The base station simply adjusts it up or down the amount you specify to display the "correct" temperature on the console.

Issue 3: Slow response

None of the sensors respond quickly. And by quickly I mean that when I turned on the fan to pull outside air into our bedroom yesterday evening, the remote lagged our HVAC thermostat display by several minutes. At one point is was almost five degrees behind and didn't catch up for five or six minutes. I played with this a bit and while I didn't chart the lag time vs. temperature change over time, subjectively it seems like the more rapid the temperature change (up or down) the longer it took for the sensor to catch up.

This could be problematic for some. If you live in an area with volatile weather like we do you could easily have a 10-15 temperature drop (or more) in five to ten minutes. During the winter this could mean the difference between bringing pets (or kids) in the house or animals in the barn vs. leaving them outside in what is now suddenly below freezing temperatures.

* Conclusion *

If you are looking for "in the ballpark" temperature monitoring and don't worry about accuracy or consistency over time, and you can cope with the remote displays not matching the base station display if you adjust the base station display values - this set is right up your alley.

Personally, I'm looking for a different product.