This seems a good time to recommend one of my low coolant alarms which works via an external sensor mounted on the outside of the expansion tank. I reckon they are more reliable than the original float technology. I'm sure most will have seen them
for sale on ebay
where they are a total bargain at just £33. Even better, contact me by private message here and I can offer a significant discount.
Admin, if this blatant promotion is not allowed, please delete this and slap me on the wrist