blockage in single pipe steam system?

an old wrench puller

Is your pressure? Turn it down, dont let it go over 2psi at the boiler. see what happens

cmcmahan_2

blockage in single pipe steam system?

Friends,
Apologies if this has been asked before. I will be brief.

I am the current owner of an 1887 home with single pipe steam system, one zone for the whole house. Upon buying the house six years ago, there was only one radiator that did not heat up reliably in the system.

After a chimney fire warranted major renovations, the house sat unoccupied and dark through a large part of last winter without heat or electricity.

The oil boiler was replaced with a new gas boiler and fitted into the existing system. Now, without any changes in pitch to boilers or piping to my knowledge, a large percentage of radiators do not heat up on the second floor that used to previously. Without steam valves attached, I do get air pushing through the hole but heat doesn't emerge and the feed pipes I can identify in the basement for the cold radiator lines remain cold.

The only exception to this situation was when I and the tech who did the installation ramped the heat up towards 80 and left it on for a number of hours - heat did appear in some radiators that had been cold but most did not.

The tech suggested blockage of the piping as the only culprit left after our experience. Does anyone have any ideas about what else to try here?

Thanks much.

Daniel_30

A condensate pool won't allow air to get through. At least a thin film of water is enough to stop high pressure steam. I can't remember the amount but it was in Dan's book. Was venting changed on any radiators? How about venting in the basement? Returns or end of main? Through conduction heat can travel through pipes that are blocked though though not enough to heat an entire radiator I'm sure. The only pitch you can't check is mainly the horizontal runouts on the the second and third floors and these would be the likely candidates for blockage.

Kool Rod

Wow! Trying to answer your questions without a lot more information is like trying to hit a dartboard in a pitch black room. From your email address, I gather you are from the Boston area so what I would suggest is you go to the "Resources" tab at the top of this page and select: Find a Professional". There are a lot of really steam knowledgeable pros listed in the Boston area and what you really need is a real "steam pro".

I'm just a homeowner though what I have learned (by experience)is that a lot of people that call themselves "heating pros/techs" know diddly squat about steam heating. If I were you, I'd be rather concerned why my "tech" couldn't figure out what was wrong with my system as steam systems are actually very simple to figure out if you know what you are doing.

Please understand I don't mean to brush off your questions, just that there are times when the best way to get things straightened out is to call in a real pro and it sounds to me like this is one of those times.

As a lot of steam problems relate to the near`boiler piping, you might want to take some pictures of the piping connected to your boiler and include pictures of the piping that goes from the boiler to the mains and post them here as that might give us some ideas as to what your problems are.

- Rod

Charlie from wmass

Steam vents are they new and of a good name brand?

bob young

need pictures

good possiblity boiler is installed incorrectly & wrong size or installer could figure out what is wrong. did he follow suggested piping diagrams ? and these are merely minimum requirements. a photo is worth a thousand words.

Jamie Hall

that's

a good simple question to start with: is the boiler sized properly for the EDR of the system? Or did it get sized for the heat loss of the house with the major renovations? If the latter, it may be seriously undersized... Only way to size a steam boiler is from the installed EDR of the system!

Mad Dog_2

It is extremely rare to have a \"blockage\" in a steam pipe

especiallt single pipe system. Need more info. Mad Dog

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Fred Harwood_3

Blockage

Jamie, you may be right. A complete review of the boiler and radiator EDR would be a vital calculation.

Phil_17

Yeah, those big pipes don't get blocked...

Your new boiler probably has dirty water. It would need to be skimmed in order to really clean it properly. With dirty (that means oily) water you'll get wet steam, and that will leave a lot of excess water in the mains. Water in the mains can and will prevent the flow of steam to your radiator.

When my boiler was replaced a couple years ago, there was one distant location which didn't heat (much like you are describing). After draining and refilling the boiler it was better, but it wasn't until I skimmed the boiler that it all worked correctly. Once the water is clean then a getting the venting up to par will make it work like a charm...

But as others have said, what is your EDR, how big is the new boiler, and pictures of the boiler and the pipes around it will help eliminate a lot of potential issues.

Bill_110

Steam systems may be simple but there are a number of things that can cause similar symptoms. I'm just a homeowner but I got Dan's Books so one thing is fresh in my mind, and about the only thing he mentioned that might cause a blockage would be when a system floods and a lot of crud gets dislodged, it might end up settling in the horizontal risers to the radiators. In that case he suggests cleaning out the pipes, which involves a lot of work and expense. I guess if you take off the valves to your radiators and shine a light down you would see water in that case.

All these other things the people here mentioned are a lot more likely and it could be a combination of different things. There is a saying I remember something like, if you hear stomping hooves, think horses not zebras - ie tackle the more likely less exotic problems first- or what Dan's books call "the usual suspects". It's better if you buy the books before you get the work done by somebody else though.
They tell you how to avoid lousy jobs before they get inflicted on you. I think that in some market areas Knuckleheads are the norm and they are in a conspiracy against the consumer though. In that case you may be in a standoff situation like me, I've got they're lousy job but I've also still got my money.

If your boiler is undersized think of the disincentive on the part of this installer to admit it! If he really wanted to do the right thing he would have sized it properly to begin with. One thing Dan does mention though is that even with an undersized boiler you should be able to heat your house eventually, it justs takes up a lot of time and fuel to heat up all the piping leading to the radiators. So if you let the temp get up to 80 and still couldn't get the radiators hot it might be something other than, or maybe other things in addition to an undersized boiler. By the way, most of the sources on the internet, more so in the past than right now, say it is far more likely for a boiler to be oversized. In my case the old boiler was double what it needed to be. Even with lousy incorrect piping in my new installation the fuel costs seemed to be down about 25%. It pays to research the boiler size you need.

I did some of the things suggested on this site that were simple but the installer neglected - skimmed the boiler, turned down the pressuretrol, insulated the near boiler piping - and I now seem to be down 35 to 40% from the old bills (which were totally outrageous). It is of course hard to quantify exact savings, but I think you can make a pretty good estimate if you've kept records for several years. You have to live with a lousy installation for a long time. The installer just blows you off and moves on to the next victim. You may be able to find a competent guy since you live in a big market. For some of us out here I think we may just be Waiting For Godot, thinking that one honest professional is going to resolve our problems. But in the meantime at least I can do what I can to pare down the problems.

mark ransley

Im no pro but have had areas that were 55 and now I can get to 85 if I use a Vari Vent or Gorton D. Simply my pipes and radiator were level, Pipe lowered maybe a 1/8th when radiator was removed to do floor and put in level, I just raised it all with a big bar.

If your Pro cant figre it out he is not a pro. Is BTU output the same on new boiler. You did replace all return vents, pipes did not move in instalation. Pressure is low. You did try new radiator vents. Your information is incomplete as you are missing it also in your understanding. You had remodeling going on, an old building with damage and it might have settled somewhere to much. Was any basement work done, I had an idiot forget to put back pipe hangers last year so I have some quick Jacks up in places. Test and replace vents, check radiator angles and look at returns. Is area not heating a seperate return maybe its just a bad vent or its the installer. I would not have paid until I had heat and would have called in a second opinion if my new boiler would not heat half my house.

ed wallace

blockage

to me it sounds like some pipes have settled or changed pitched and now have a water pocket blocking the steam