Water Spewing from Steam Radiator Hydrostatic Valves

alex124

I have a one pipe steam radiator system in a new house, in which I have never used the heating system before. The boiler was replaced about 4 years ago and all of the radiators were removed, cleaned, and reinstalled with new hydrostatic valves just 2 months ago. (Also new inlet valves were installed for each radiator.)  Since servicing the radiators, I have found water to be spraying out of the air vents at one end of the house.

To give a little more description to the system, the boiler is located at the back of the house in the basement. There is one radiator directly above it on the second floor. There are two radiators at the front of the house, one on the first floor and one on the second floor. The radiator at the back of the house is about half the size of the other two. There is new Maid-o-mist #6 hydrostatic valve on every radiator and also one older valve on the water return pipe, just after the last riser, which goes up the to the radiators at the front of the house. The radiator piping is at least 30 years old, and probably even older.

Since the first time using the system I have found water spraying out of the hydrostatic valve in the basement and on the radiators on the first and second floor at the front of the house. No water comes out of the radiator on the second floor at the back of the house. Proportionately more water comes out of the basement valve then out of the first floor radiator then out of the second floor radiator.

I have double checked the boiler settings and confirmed that the PSI is set correctly and that the boiler has sufficient water but that it is not overfilled. I have also ensured that all radiators are tilted towards the return pipes to eliminate standing water in the radiators. All inlet valves to the radiators are fully open. Nevertheless, water still comes out of the hydrostatic valves.

My initial suspicion was that the radiators did not have the correct tilt, but this doesn't explain the water coming from the basement valve, where the pipe has no sag so there is no sitting water. I also suspected the boiler could be overfilled, but operating it with less water yields the same result. I am looking for any advice on what additional problems could be causing this?

Given everything but the piping is new, could the culprit be the size of the hydrostatic valves, and would that explain why water is coming out of them?

Jamie Hall

What is the psi setting? You do say it's correct, but what is that?

The water coming out of the vents -- the correct term, they are not hydrostatic valves -- indicates seriously wet steam or excess pressure or both, and quite possibly problems with the near boiler piping. You might want to get a copy of a little book, 'We Got Steam Heat", which is nice introduction to steam heating -- available either from the store on this site or, I believe, Amazon.

Erin Holohan Haskell

@alex124 this may help: https://heatinghelp.com/systems-help-center/spitting-or-hissing-air-vents/

pedmec

You might want to send pic's of the boiler and a radiator. A full view of the boiler.

DanHolohan

Are these the vents?
https://www.supplyhouse.com/Hoffman-401475-508-1-8-Straight-Steam-Convector-Air-Valve-3521000-p

alex124

Thank you @Jamie Hall, the Diff. PSI is about 0.25 and the main PSI is 2. The internal syphon PSI gauge does not seem to move off 0 when the system is running, although between catching water coming from the radiators, maybe I missed it jumping up.

@Erin Holohan Haskell, I did review that link but it doesn't describe possible symptoms of some of the problems it lists. None seem to match the issue I have, where large amounts of water come from the system.

@pedmec, see one attached, if useful.

@DanHolohan, no. The air vents are these: https://www.supplyhouse.com/Jacobus-Maid-O-Mist-J6-6-1-8-Angle-Air-Valve-3566000-p. They were provided by my last plumber for all radiators. The main vent is a different model, original to the piping, that I cannot determine. 

DanHolohan

Those are not hydroscopic vents. The one I showed is. I've never enjoyed seeing those on steam systems, even though they're sold for steam systems. It takes too long for the discs to dry and for venting to continue.

neilc

so many ways to pipe one wrong

Jamie Hall

Oh dear. Well, try dialing the main back to 1.5. But... I don't think that will help much. Unless there's something I can't see in the photo, that near boiler piping is just plain wrong, and is pretty well guaranteed to get you nice wet steam. There is no header, and what is attempting to be an equalizer (I think) is coming off the side of the riser, where it will do no good at all.

I'm rather afraid that the fix is to redo the near boiler piping so that it is correct. Steam is remarkably forgiving, but there are some things...

mattmia2

I can pretty much guarantee it hasn't been skimmed either which might get it down to just bad water hammer instead of all the water immediately residing in the mains.

alex124

Thank you all for the help and suggestions. I had a good plumber come take a look at it and the end problem was a combination of the fact that the boiler had never been skimmed and that the boiler had not regularly been emptied and refilled to clean out the tanks. Three washes later, and with the installation of a new skim valve to blow off the oil, the entire system was cleared up and it now runs perfectly with no water coming out of the radiators.

pecmsg

Where is this boiler?

Your plumber sounds like he "Might" know what he's doing but, if he's not worried about that near boiler piping I doubt it.