Boiler in question is a 2.5 million btu weil mclain. One t/stat and no zones. From what I understand it's about three, maybe four years old.
On a call for heat, The boiler fires and runs for about four minutes. It's shutting off on a pressure safety (3 psi).
I'm assuming, that under normal operating conditions, It should be at 1.5 to 2 psi.
Boiler water in sight glass is filthy brown. I have no history on the service of this boiler. It' safe to say, It's been a while.
So, my questions are; Why are there three pressure controls? Are they redundant safety's? First one is set at .5 psi cut in with a 3psi cut out. Second one set at 2psi cut in with a 4.5psi cut out. Third one is manual reset at 5psi. Is there any way to adjust pressure on the boiler? How about temperature?
My sight glass is a bit over half way. Is it safe to say that my water feed is not over feeding?
Boiler has two low water cut off's. One is a combo feeder and the other is a manual reset. I blew them both down and got a lot of nasty brown water. Even some clumps towards the end. Refilled the boiler and still had same high pressure problem.
Tomorrow, I plan on skimming the boiler and blowing down the low water cut off's until it comes ot clear. I'm hoping this solves the problem.
Any input would be greatly appreciated.