Yes I got heartburn, glugging the water did help and it settled down fairly quickly. I took gaviscon when it was particularly bad but I am not sure whether this is officially "allowed".
Also you could try splitting your packs as I have read that this helps some people. I drank more water & like Porgeous said this did seem to help. I had heartburn in in the early days but I have not had it for a while it seems to settle down after a few weeks. Hope it improves for you!