I have a 30 gal 240vac elec water heater that is less than 3 years old. Recently, I have noticed that the hot water seems to be giving out after one shower. I would not think that a t-stat or element would be going bad this soon. We have a lot of lime in our well water. Could lime deposits on the elements be causing the problem? How can I clean (decalcify) the tank? Can I 1) shut off the supply valve, 2) connect water hose to drain cock, 3) open PRV, and 4) pump an acid solution into tank? Help!