Steam Heating - Clogged Steam Pipe?

paulasack

Hello! I live in the Boston area and have a 1941 home with steam heating. Our home heats up great but I have one radiator that does not produce heat in our living room which is the room over the boiler room. When tracing the cast iron steam pipes throughout the house, the pipe that serves this radiator is second from the main pipe. After troubleshooting with my oil guy to no avail I’ve been troubleshooting on my own.

For the sake of this post, I fired up my heat for 30 minutes and took a thermogun to the pipe. Within a 3 ft section the temperature dramatically reduces where are other steam pipes in the house are consistent. See pictures below.

Could there be a clog or corrosion over the years in the steam pipe? We had hard water in our house over the years but have since put a water filtration system.

The vent has a new bleeder, has been vacuumed etc., pitched correctly but it just doesn’t receive heat. We’ve lived in the house for 2 years so I don’t have too much history.

Any feedback or suggestions are welcomed! Thank you!

ethicalpaul

Almost certainly not. It's either a venting problem with that radiator, or a pitch problem where part of the pipe is collecting water which acts as a trap that stops steam.

Your water quality is irrelevant here because all that should be in that pipe is steam and pure distilled water. Steam pipes do corrode eventually, but they don't tend to clog.

I will add that your boiler water appears atrociously dirty and your near boiler piping seems very bad that that could cause surging which might come into play.

Can you explain what you mean by "the vent has a new bleeder"? Bleeder is a hot water term, not a steam term.

retiredguy

Make sure that the valve to that radiator is all the way open, Sometimes the shut off disc inside the valve will break or wear out and drop down off the stem not allowing the valve to open. If this is the case you will have to remove the valve's bonnet to access the disc. Anytime I do this I throw the disc away since it probably not needed. Post a picture of the radiator and the valve so we can see what you have. There are guys on this site that can help that are in your area.

EBEBRATT-Ed

I agree with @retiredguy I would suspect the radiator valve if the rad is pitched properly , has a good vent and the piping is pitched properly.

Very unlikely a pipe clog.

mattmia2

Put a level on the pipe to verify the pitch. It looks like it is pitched properly but the ceiling could be very much not level. Also look at what is happening after it goes through the ceiling and how it gets to the radiator. Another thing to try is to take the vent out altogether and see if maybe you have a bad new vent or something. And 1 pipe valves need to be either all the way open or all the way closed, if the valve is part way open the radiator will tend to fill with condensate and not heat.

paulasack

Thank you for the feedback. Here’s some more pictures

ethicalpaul

The vent is certainly not too small ("D" is a very large vent size)

You could remove the vent and attempt to blow through it to see if it lets air pass.

mattmia2

I'd probably turn the ell for the vent 180 degrees if there is room so the pitch is toward the radiator instead of away. I don't think that would cause it to not heat unless it is filling with water and it has a float function but it could cause it to spit. I'm not sure what that material is inside the enclosure but it looks a lot like it could be some sort of asbestos cloth so I'd be careful about disturbing it unless you have had it tested.

Obviously the quick test is to remove the vent and see if it heats. Probably have some heavy gloves and the vent ready if you need to put it back in to a hot emitter.

I would actually just use a straight vent instead of an angle vent for it.

Can you look up in that hole in the ceiling and see what is happening with the piping there? There is also the question of why someone made that hole.

Btw those are convectors.

Edit:

or is the hole in the ceiling by a different runnout?

JUGHNE

Is there a supply valve on that convector?

Does the pipe riser from the basement go straight up to the unit or does it have a set of 90 ells above?

Someone else, before you, may have made the holes chasing this problem.

clammy

Have u tried check the radiator vent to see if its clogged or water logged . Also does your system have working main vents and last but not least your steam mains are uninsulated which is not the greatest thing . From your boiler pics the piping is not what i would call acceptable at least not by me. The only way there would be a blockage would be if the system had flooded and rust and debris drained back and clogged it ,i only seen this a few times and also there mains where not insulated . You could remove the radiator vent and blow into it if there alot of resistance then your clogged. You could remove the convector and try to flush the run out back to the main . Have you tried running the boiler w the vent removed ? Also w out insulation all of your steam mains have to be hot enough so as the steam stops condensing into condensate hence the temp drops and the further from the boiler the colder it will be . i noticed the two main vents setting on top of the boiler where they removed and plugged or where they replaced and if replaced where they at least a name brand (gorton .hoffmann,)non hardware home depo china pooh? .In all my years of working on steam the best roi and increase of performance of a steam system was re insulating the steam main w 1 inch fiberglass pipe insulation in all systems fuel bill lower distribution time cut and easier balancing the system . Most oil co love uninsulated pipes and no main vents makes ya burns more oil more short cycle more money list goes on if you got flame you got heat attitude . If all things being equal you want your complete steam main up t the main vent hot and then look at your run outs, if your run outs and rads are hot one at a time it a main vent lack of insulation issue . Steam can be fickle to one who do not look at the whole picture .

peace and good luck clammy

mattmia2

https://forum.heatinghelp.com/discussion/comment/1813681#Comment_1813681

It kind of looks like the supply side of the convector element may have dropped down, if there is a swing joint inside of the ceiling that could now be pointing the wrong way.

mattmia2

https://forum.heatinghelp.com/discussion/comment/1813685#Comment_1813685

And the pipe won't be clogged per se but there will be sediment in the pipe that prevents the condensate from returning so it will heat up to the point where that sediment is holding a pocket of water in the pipe and it will usually eventually evaporate that pocket of water(with some violence) and heat but it will take longer than the rest of the system.