1890 Oswego NY Victorian House Museum, First problem, first floor balance & no heat rads.

NealJ

The biggest problem I have is system balance and no-heat radiators. Refer to attached photos. All radiators are basement ceiling mount (to floor or wall grates) except #8 & #9, which are normal cast iron radiators. #9 is two pipe. #8 is single pipe and I believe added maybe 10 years after the system was completed.
Ceiling radiators 1, 4, & 5 work great, and I’m thinking the thermostat may be taking out the boiler before everywhere else heats up, so I valved out radiator #5 which helped a lot. The thermostat located in room R102 should really be in the center hall, but radiators 2, 3, & 8 have no heat. #2 is disconnected (I assume must have leaked at one time), steam never gets to #3 (I removed the vent, no steam. Either piping is blocked or not enough steam pressure to drive down - see piping photo), and I have no idea why no heat to #8. Replaced the vent but didn’t help it. #6 & #9 work OK. Ideas?


Disconnected Radiator #3



First floor heating map. All radiators ceiling mount in basement except #8 & #9.



Piping to radiator #3 that doesn’t get steam even with vent removed. Either the pipe is plugged or the thermostat takes out the boiler before enough pressure is built up to drop down into this pipe.



Piping to radiator #8, which does not heat. This is a single pipe radiator that I believe was added sometime after the system was installed. Vent replaced.



Radiator #3 that gets no steam even with vent removed. Shows previous leaks patched.



Basement steam configuration. Boiler and main trunk lines.

KC_Jones

Couple points to not only help the conversation, but also for your education. A blocked steam pipe is rare, really really rare. I'm not sure if I've ever seen it on this site in the almost 9 years I've been participating here, so don't let that concept distract you.

Second, you don't want pressure in a steam system, more pressure means slower steam, lower efficiency and slower heating. I know that seems counterintuitive, but that is the reality. So when you comment "not enough pressure", trust me when I say this, the problem is most likely too much pressure, and I'll explain why.

Pressure in a steam heating system is back pressure. It comes from a combination of things, which are boiler size to system size, and then add in the venting. So when the boiler first fires you want enough venting that the expanding steam can move down the pipes as unencumbered as possible. Not enough venting, the air can't get out of the way fast enough, so the steam slows down and you get pressure. So when you have slow, or none heating radiators you have a venting problem creating a balance issue.

So, for venting the very first thing is to find the main vents in the basement. You want enough main venting on the basement mains to vent all the air out, fill them with steam, before any radiators start heating, with proper venting this should only take a few minutes under normal conditions. After that the radiator vents come into play. You vent those according to geography relative to the boiler and main, size of radiator, and desired heat level. So if you want the room a little cooler you can put a smaller vent on and that room will run a bit cooler than the rest, that said getting everything even is usually the first step.

If you measure the mains, both the length and pipe size, we can recommend how much venting would be appropriate. If you locate the main vents you currently have (if any) we can suggest if they are appropriate or not. My speculation is you have little or no main venting and that is one of the biggest problems here.

mattmia2

Trapped water will also kill the steam, it will cool and condense it and prevent it from progressing. The boiler may be throwing water in to the mains or the pressure may be pushing water out of the boiler and up in to the system if it actually builds as much pressure as it is set for.

NealJ

Thanks so much for the education! I replaced the vent at the end of the main header (in-kind) and certainly other radiators tapping off downstream of #3 are getting steam. I removed the vent from #3 with the boiler running and I would have expected steam. I know some of the condensate drain pipes are at least restricted. Photo is the condensate drain from the end of the main header, though that still wouldn’t explain the lack of steam when the vent is removed.

KC_Jones

Yes clogging in pipes that primarily deal with condensate can definitely happen, and to a point, to be expected. It typically won't impact the steam performance unless it gets so bad the water backs up into the steam mains and restricts or hinders flow.

If you have main vents, I doubt you have enough. Depending on how long and what size the mains are you could need multiple Gorton #2 vents on each main.

Some terminology for you. The header is at the boiler only. The mains come off the header, so the pipes (I think) you are calling header are actually the mains.

Jamie Hall

Tackling this piecemeal is going to be difficult. As we noted in another thread, you are going to need to be the expert -- and you might as well start with your own system. And a book: Dan's The Lost Art of Steam Heating Revisited, available either from the store here or from Amazon. It's worth every dime. Sit back, read the book, visit the basement, read the book some more, and really figure out the whole system -- how it was supposed to work originally, and how it might be working today -- and why it might not be working.