Well this is how I spent my Saturday - leak finding for the soon-to-be-ex wife! The joys of living in the countryside - and sods law, it was the only radiator in the house that I hadn't re-plumbed myself! I did however find a 1960s fanta can - wonder if it's worth anything??
Definitely think it's rats - got a call this morning to say that there is another leak. Boiler is showing no pressure, although this time round the hot water won't work either. There's a slim chance she can claim on the house insurance, but as I've now moved back to England she's going to have to get a professional in. I told her it was rats and she needs to get the exterminator in, poison at the very least - but of course, any advice that comes from me is automatically considered wrong