This solved my problem, humidifier is back in action for the last week after installing this sensor. I have a Sani-Dry portable 109 pints/day dehumidifier which started staying on all the time and displayed an E2 error. I called the manufacturer but they would not provide any information besides phone numbers of service companies in my area. I called the company that installed the unit 10 years ago, but they never returned my call. So I removed the humidistat sensor which is right under the filter, and found that this sensor matches very closely the circuit layout and design of mine. Took a chance, ordered this, problem solved. Lots of $ saved.