I found the problem. A check valve was bad. When the water comes in from the street it then goes through a check valve which in turns goes through two other things a hot water, water pump and a water mixer, to regulate the hot water temperature. But the water pipes split up before that. One goes to be made into hot water and the other obviously stays cold. So since the 1 inch and a quarter check valve wasn't working in was spilling the made hot water from the boiler back into the cold water line. So it wasn't a boiler problem, but a plumbing problem which I was able to correct by simply changing the check valve. Thanks to the consultation of a oil company. That was first on the list in the process of elimination and it worked. Thanks for responding.