On a service call today I had a complaint of an area being to cold and it sounded like the system was shutting off at 4 pm. I reset the time clock and the boiler came on and the operating control cycled the boiler off at 148. I checked the hot deck temp and found it was only getting up to 82 degrees, then dropping down to 75. 3 of the five zones where sitting at 8 psi, one was at 20 and one was at zero. The one zone at 20 psi I turned the temp up to 73 and the pressure dropped to 16 psi.The little amount of work I have done with pneumatics I thought that the hot deck should be set to 95 , when I opened the panel door there was a control that said hot deck and both gauges were at zero. One gauge was on a spot labeled "b" and the other gauge was on a spot with a number three. I did not see a dial on this but is that the item that I would need to raise the hot deck temp? Is there a site I can start learning about the basics and get a better understanding of these controls?