Welcome! Here are the website rules, as well as some tips for using this forum.
If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
I have what I believe to be a subtractive pressuretrol ( Honeywell L404F) and in reading the "Lost Art" on page page 14 Dan says these mix alot of guys up. I think I am one of them! There is a main scale and a diff scale. I set the main at1-1/2 and the diff at 1. but the boiler seems to be shuting down too quickly or short cycling. Any ideas? this is a one pipe system with a Burnham Independance gas fired boiler. I also just installed 2 new Gorton #2 main vents on an antler. Thanks