Dave new temp switches come on a few degree's sooner than the regular ones, improving the cooling, both Dave and I like them. But they are a different size and the water probe is bigger, enabling the switch to be turned through 180 degrees with out any danger of air locking around the probe, so that the wires come in from the top. We have both operated like that for the last two years, so PLEASE don't tell me why it won't work Martin, because it does.