[Alf ista]

Hi Ron and many thanks for the advice. Before I went down the road of using the stud extractor I did eventually use proper penetrants which I got after earlier advice. I also tried heating the block around the stud and I did try the tightening first and then loosening technique. But all to no avail. I now know that progressively drilling it out would have been the best thing to do in this case. Anyway, thankfully it all worked out in the end. I have learned stuff and will now move onto the next episode with some experience and gained confidence. Best of all, I was able to finally put on the thermostat and its housing and complete the job I started ages ago. I finally filled up the rad last night and was able to get all the air out. Would you believe it not a leak anywhere and everything worked a treat! I was able to bring the old girl out for a spin today for the first time in ages. Needless to say I had a big smile on my face!! By the way, those thread cutters are known as "tap & die" sets over here as well. Thanks to everyone for the help. Hugh.