Steam Problem - High Pressure?

David_9

I have been having some problems with my steam heat - some water hammer, unable to heat all the radiators, and now maybe pressure?

First, I went through and replaced all the vents on the radiators, then the vents in the basement (I noticed that in the past rusty water appeared to have leaked out the vents and around some shut off valves, judging by the deposits around them). This solved the water hammer (I thought) and all except the furthest radiator now heat - it's a small radiator, vents air, but the pipe seems to heat up to the radiator and then stop (the cast iron pipe is necked down to a smaller copper pipe for the last 4 feet or so).

I'd left it at that, until I came back from a trip and turned up the heat. After a bit, the heat came up, then I had severe water hammer from the room I was in. Water and steam were leaking out around the shut off valve. I heard water leaking around the shutoffs of other radiators. I looked at the boiler, and the pressure gauge was at 10psi. This seemed high! I think it was 1-2psi before. There was no water visable in the sight glass either! Yet the low cut off wasn't engaged? I flipped off the boiler, and immediately heard the condensate draining back into the boiler. When it filled up, the pressure had dropped to 5 psi, but didn't go lower? I unscrewed vents everywhere, nothing came out, but still 5psi on the gauge. Wondering if the low cutoff worked, I drained water out the boiler - and drained, cause I had switched off the power. Duh, it was engaged when I turned it back on. I slowly added water to the system (Some weird black liquid came out before rusty water when I drained, BTW). Pressure had dropped to 4psi, but didn't go to 0 until off overnight. Why did the pressure get/stay so high, even after draining? There is a Honeywell control labeled "cut-in" set at 2psi (The boiler for the other condo is set to .5?) I read in another post to set cut-in at .5 and cut out at 1.5? Didn't see a cut-out, it's a Burnham boiler. What do these do? Why 10psi? Why didn't the low water cut off come on?

Earthfire

pressure

Might be a good idea to get a steam pro to check out that system .The first things that I would check would be the low water cutoff and pigtail to the pressure trol for clogging, and repair and replace as needed.system may also needa flushing and cleaning.