This is quite a puzzle!

I would check to see if your diptube supplying fresh water to the tank is still in place. It is on the inlet pipe and directs cold water to the bottom of the tank. Part of the reason for diptube failure is high temp hot water….Lou

You do not specify which type of system you have. It could be a heating system that also heats the hot water, or a water heater that heats the house. The controls for the two are different and the way the water gets heated is also different. The one item that is common to both types is a temperature limiting device to prevent the domestic water from getting as hot as the heating system. If that fails or goes out of adjustment, then the delvered water will either be too hot or too cold and the actual delivered temperature will depend on the amount of water being used.: Check THIS one out. I have a gas hot water heater that heats the house AND the hot water. It had been working fine for about 1 year – nice and REAL hot just the way I like it. Then all of a sudden the hot water got about 30 degrees colder! I couldnt figure it out – what could cause such a sudden drop. The wierd thing is, when I have the heat running, the water is just as hot as it was the day I moved in? And if that isnt quirky enough, if you let it run it gets HOTTER the longer it runs, but never gets as hot as it used to be. What the Heck? Whoever figures this one out has got to be a genuis or a hot water guru. – Thanks – Jimbo

: You do not specify which type of system you have. It could be a heating system that also heats the hot water, or a water heater that heats the house. The controls for the two are different and the way the water gets heated is also different. The one item that is common to both types is a temperature limiting device to prevent the domestic water from getting as hot as the heating system. If that fails or goes out of adjustment, then the delvered water will either be too hot or too cold and the actual delivered temperature will depend on the amount of water being used.: : Check THIS one out. I have a gas hot water heater that heats the house AND the hot water. It had been working fine for about 1 year – nice and REAL hot just the way I like it. Then all of a sudden the hot water got about 30 degrees colder! I couldnt figure it out – what could cause such a sudden drop. The wierd thing is, when I have the heat running, the water is just as hot as it was the day I moved in? And if that isnt quirky enough, if you let it run it gets HOTTER the longer it runs, but never gets as hot as it used to be. What the Heck? Whoever figures this one out has got to be a genuis or a hot water guru. – Thanks – Jimbo

Im pretty sure it is the dip tube – there is a Message out from Bradford White on defective dip tubes made by Perfection on certain model serial numbers, mine included. My hot water heater sends hot water to the blower. I am going to replace this myself – it looks like to me all I have to do is take the cold water inlet connection off and replace or repair the dip tube. Thanks to HJ and especially Lou for their help on this. Anybody see a problem with me just ripping off the connection and replacing the tube or am I delving into professional plumber territory? It seems easy enough to me….