> They rarely fail and do their job even in damp environments. I take care of my better half's hotel with approx 100 of these installed and we replace one of these once every couple of years.
I had to replace about half of them within the first ten years of usage in our floor heating. It may have been a bad batch, but I would definitely not claim that the rarely fail. My car did not fail once during that time.
I bet poor manufacturer, or poor quality, or poor batch. Also maybe NC (normally closed) vs NO (normally open) behave differently? In any case, the ones we use are solid, especially given they are installed on damp AC ice-water circuits.
I had to replace about half of them within the first ten years of usage in our floor heating. It may have been a bad batch, but I would definitely not claim that the rarely fail. My car did not fail once during that time.