I've got a 4 year old 50 gal.GE gas water heater(12 year warranty) that puts out hot water at first but then there is a temperature drop in the water afterwards. Occasionally you hear a pssshhht sound coming from it, kind of like the noise you'd hear if a pressure relief valve was going off.
I have city water, but I've had some shower heads that have limed up on me so I assumed the water heater has limed up. I've drained it a couple of times now with no change. I called up Tri Bros. Chem. to purchase some Mag Erad to try and flush any lime deposits out and the guy said I should inspect the dip tube before I buy his product.
Is there any way a dip tube could deteriorate after four years? And should I even be doing anything to the heater myself considering it's still under warranty?