I was fairly certain the only thing wrong with my boiler was the control unit, even though I could not be absolutely certain.
I went online and did a search about control units.
I asked the question, ‘What happens when the control machine breaks?’, and got a lot of answers. The real main thread of the answers is that if the batteries in the control machine die, or the control machine malfunctions, it can no longer communicate with the heating and A/C system. This actually means the boiler could continue to run or won’t run. If you have the air conditioning on, it won’t reach the desired temperature, or it could freeze you out. It was funny to know the control machine could be the brain of the heating and A/C system. This simply made me wonder what happened before they had control units. I should have known it would be the same answer, then without the control unit, people had to manually adjust their temperature, then you learned how much coal or wood you needed in the boiler to keep the property moderate without getting it too hot. I also don’t know about air conditioning, because my mom and dad didn’t have air conditioning, but that didn’t matter. I was now even more sure that the only thing wrong with my boiler was that I needed a modern control machine or modern batteries at the very least. Instead of calling the heating and A/C supplier, I changed the batteries, but nothing happened. I then went to town and bought a modern control machine just like the digital control machine I already had. When that didn’t really work, I was deflated. I was now going to need to call the heating and A/C supplier.