OT: any steam heat wizards here?

[J Tiers]

You have to ask yourself, why is the heat getting only partway up the pipes? Best answers to that are:

Problem making steam (flues clogged, horribly bad combustion, flue gas not going where you think, burners not all working, not enough water)

backpressure preventing flow (air vents not open, etc. Might not be much pressure to prevent flow, and/or divert it elsewhere)

Leaks (probably right near where the steam quits heating)

A combination of those factors.

What are you "absolutely sure of"? Double check that, and assume nothing when you do.... make the system PROVE that each factor is good.

[deltap]

Download " ITT steam book". I think it is free in pdf form. It has a chapter on troubleshooting steam systems. It explains the different types of steam systems and how they work. One pipe was the first and later systems, two pipe, vapor, and vacuum were improvements.

[gellfex]

"2012 boiler, sight glass and vents clear", doesn't mean the tricocks arent plugged giving you a false reading. Automatic water feeder or manual?

9 year old boiler, when was the last professional cleaning, flame adjustment, AFUE determination? Usually done annually in the fall.

Professionally serviced and cleaned last March. There's no issue with the sight glass. VXT automatic water feeder with meter.

[reggie_obe]

Shut off the feed water and monitor what happens. Remove vent at closest radiator. One pound should be enough to get heat to radiators. Boiler may be on the small side. Did it work before. 130mbh is a small steam boiler.

Boiler make and model#?
This is the only unit or is it just for the rental units?

[deltap]

Shut off the feed water and monitor what happens. Remove vent at closest radiator. One pound should be enough to get heat to radiators. Boiler may be on the small side. Did it work before. 130mbh is a small steam boiler.

[Jerrythepilot]

Feel the piping out from the Hartford loop. A leak on the return side could explain some of your symptoms.

[reggie_obe]

That may suggest that the heat exchanger may be clogged up. I once saw one that was so clogged with carbon (I think the burner got out of tune somehow, don't recall the details) that something similar happened.

"2012 boiler, sight glass and vents clear", doesn't mean the tricocks arent plugged giving you a false reading. Automatic water feeder or manual?

9 year old boiler, when was the last professional cleaning, flame adjustment, AFUE determination? Usually done annually in the fall.

[gellfex]

2012 boiler, sight glass and vents clear. I know that pressure may only be in ounces, but it should be there. There's none detectable using this hose pressure gauge. The mystery is where the BTUs are going, they can't just be vanishing! I clocked the gas meter at 130k BTU/hr.

[alanganes]

There are still a lot of old steam systems around this part of the country. I grew up with one and have worked on a bunch of them but it has been may years. I can't say that anything you describe jumps out at me. But as you said, physics dictates that all of that burner heat is going someplace. If there is no steam, then it's not heating the water. That may suggest that the heat exchanger may be clogged up. I once saw one that was so clogged with carbon (I think the burner got out of tune somehow, don't recall the details) that something similar happened. Though in that case it became obvious after a while as the smoke from the burner was backing up into the house and started to stink the place up. Has it been cleaned lately?

Can you tell if the temp of the water in the boiler is rising at all? (oops, I just re-read your OP, obviously there is some if the risers are getting warm...)

[reggie_obe]

Tough to find a steam heating expert today. One pipe systems and experts even less so.
If your firing continuously, steam gauge is reading zero and sight gauge water level not dropping, where is the heat energy going other than up the stack? How old is the boiler?
Many blocked firetubes in the boiler? Much rust and calcium scale in the waterjacket?

[J Tiers]

had that nasty steam heat in the past.....It's cheaper than hot water, that's about it... But that's what you have, so....

The radiator vents are one place to look. Any painting done recently? I've seen a lot of those painted over.

Water level high enough in the boiler? If some risers get hot, there is some water in there, but how much? Sight glasses can get clogged, and if the level never varies it might be.

No pressure? Shouldn't really be much, but if all the vents are closed, some may build up if it is firing. Probably no pressure because the vents are open, but worth checking

From cold, do ANY of the vents hiss? They should, as the steam drives out the air.

[gellfex]

Are radiator air vents opening to allow air escape? What about you main line air vent(s).

If anything I'm overvented, whatever that means. There's Gorton 2's on the 2 long mains, and plenty of vents on the rads. There's just no pressure. I saw this simple 'water column' gauge on a heating site and installed one, but it registers zero pressure. 1psi=27.7 inches of water. The steam tech was dubious about it being accurate, one reason I'm dubious of him! If there were any pressure it would push water up the tube, but the level is the same as in the sight glass and never budges.

[reggie_obe]

Are radiator air vents opening to allow air escape? What about you main line air vent(s).

[gellfex]

I'm struggling with a misbehaving single pipe steam system, and I thought at least someone here would be on the same wavelength as me. My steam tech's answers don't make sense.

Zero pressure. No water loss (per VXT logging fill meter). Firing continually. Cold radiators abound, a few riser lines get heat. Where are the BTUs going? It's not like the thermostat is satisfied and shuts off before some rads fill with steam, its firing continually and steam should EVENTUALLY reach them all! One theory is it might be condensing and not reaching the rads, but the heat HAS to go somewhere! Either up the stack, or into the water. You can't keep shoving BTUs into the boiler and they vanish!

Steam tech wants to change out the ancient condensate returns, a huge job. I cannot disagree that it's a good idea in any case, but I'm unconvinced that it will solve the mystery of the vanishing heat.