Guest
I am assuming that you have an electric water heater. The air tank that you mentioned that is intalled above the water heater is probably a thermal expansion tank that has no effect whatsoever on your situation. You should let some of that air out! It should tell on a dataplate how much of a precharge of air should be in it. These are usually small tanks oh about 10 inches in diameter and maybe 12 inches in length that are installed to absorb any build up of pressure from heating water. Seems to me that it should have about 15 lbs. of air in it or so. Also I would not set the temprature above 125 degrees as serious burns can occur and even death. It was not clear if you dont get hot enough water at all your fixtures of if it is just a problem with the showerbathtub.If it is just the shower or tub it may be that you have pressuretemprature balance controls. Some faucets have only a temprature control which limits the temprature that can be achieved. These are most often single handle faucets and you have to remove the handle to get at the adjustment. If that is the case just adjust it towards the “hotter” setting. Some localities require a temprature limiting device to be installed at the water heater. These also have an adjustment knob that usually says “hotter or colder” on them. There are potentially other things that could be the cause of not enough hot water like a broken or missing dip tube in the cold water inlet of the water heater,hot and cold water lines that were inadvertantly linked somewhere in the system or if you have an electric water heater burned out lower element or faulty thermostat. Hope this gives you some ideas on what to look at!
