Review on 🌡 WH8040 1%~99% RH HM-40 Type Digital Air Humidity Control Controller 110V by Todd Raynie

The relay that is supposed to control the on/off function of the humidifier connected to this unit has failed. During troubleshooting, the relay stayed closed whenever the humidity exceeded the maximum value. Even though my old-fashioned humidity sensor read 95% humidity, the reading began to drop until it was about 7% lower than the other sensor, and continued to drop as this device's reading neared that level HS. And it could be the result of a faulty sensor. So two hits and you're out of action. Update: When I first started the humidifier, the reading rose very quickly until it was five percentage points off the high, and then the readings began to fall, as mentioned earlier. To test the unit, I disconnected it from the humidifier and adjusted the LS and HS settings up and down and checked for continuity between the relay terminals. Regardless of the settings, the relay remained closed.