Last night, I went to test my heating loop and it immediately shot to max temp and didn’t come down. Obviously the heater was dry and the pump wasn’t moving anything. I managed to panic shut it down and don’t think I did any lasting damage.
I realized that my weak coolant tank was the problem since it was collapsing and not allowing me to get a good vacuum. The original fill I just vacuumed on the hose directly and didn’t have the tank on there. It also started leaking after cutting crushed by the vacuum.
So I took a quick look at O’Reilly’s for something pressurized and cheap. I found this one. It was cheap and in stock. I had to get a T fitting and some caps to find something that could go from 3/4″ (outlet on tank) and 3/8″ (hose to my system). I also capped off the overflow opening on the new tank.
The vacuum this time was much better and it managed to pull a good vacuum and hold it for a couple hours while I did dinner and bedtime. I went around the squeezed all of the hoses just to be sure. I let it fill and hit the pump and it is much better. Now I need to figure out how to mount it and if I want to drain the tank and shorten up the hose going to it.
Unfortunately during testing I managed to short out the Teensy on my battery controller. So now I need to solder up and program a new one before I can test the heating system again.