I had the same problem and followed the advice of oldturkey03. After a couple of hours of soaking with the CLR and water mixture I ran the mop without the mop head and had some amber colored gunk come out. Repeated this the next day and now the steam came out much better. Drained the tank and refilled with the vinegar water mix and ran the unit in mop mode until the steam and water drops came out clear. The mop works like new again!