Hi everyone, im a newbe and hoping to get to get some advice or pointers in right direction please if you can. I have a backboiler and tank cylinder. Last week my hot water was just tepid warm, I called out gas man who checked things, he said the header tank in loft was really low as the ball joint had stuck. He released this and said things should be fine. The water did improve in temperature slightly but still not hot enough for bath. I called him back he then said because of the low water level in the header tank air is now in the main tank to which he fitted a air release valve. This was Friday. Friday night I was able to get a good hot bath, all seemed to be working fine. But now the temperature has dropped again, its still hot enough to wash up but not for a bath. After looking under fire when hot water fires up, the flames don't seem as high, ive now put central heating on and that seems fine and I can hear the back boiler firing up. but cant hear it when its just hot water, any advice anyone ..thanks