Got some brilliant news...last night we went to the stables and gave the waterer a good scrub with coca cola..couldnt believe the amount of the rust the coke removed (dread to think what it does to our insides!!! ) We then popped some cut up apples in the waterer and managed to get him to take them out but still couldnt get him to take a drink but at least we were one step on..gave him a bucket of water to drink before we left still pulling our hair out on what to do about the situation. When we drove in to the livery yard this morning to give him his bucket of water we could see him over by the waterer..as he heard our car he popped his head over the door and yes he had been drinking as he had water dripping from his mouth.
What a relief I was getting so worried.
Thanks agin for all your replies