blocked lines

JohnB

I have a customer that has 11 radiators in his home and 9 won't heat.  I have removed the vents totally with still no help.  A few years ago, he had some pipes replaced and the plumber welded new lines in after breaking the old fittings.  When he was done, he added a boiler cleaner to the system.  Then he left, never to be heard of again.  After that, the heat stopped.  I have used a thermal gun to follow the heat in the pipes and I am finding definite "stops" where the temp drops significantly. 



The hardest part is that there are no valves or unions anywhere in the system so I can't just open it and try to flush it out.  Even the radiators themselves have no valves.  Most of the blocked pipes are 1" and almost 100 years old.  I am a bit leery on cutting and re-threading since I am sure that I will shake more rust free and cause more blockages.



Can I pressurize and flush through the vent openings?  Is it worth it?  Would over filling the boiler and draining help or hurt? Any help would be appreciated.  

Rod

Blocked Piping

Hi- Could you possibly take some pictures of the system- radiators, boiler and near boiler piping.?  What type of steam system is it?

- Rod

JohnB

blocked lines

Sorry.  The system is a one pipe, gas fired boiler.  The radiators are the old cast iron style with several different vents(Gordon, Dole and Varivent).  I don't have any pictures, but there really isn't anything outstanding about it other than the fact that I can't get into it without cutting or going through the vent holes.

Rod

Blocked Piping

Thanks for the info. When you mentioned 1 inch piping I was thinking 2 pipe system. Can you remove the radiators?  Is there any thing special about where the piping is blocked, at a fitting, on the radiator laterals at a 90 degree elbow etc.?

- Rod

JohnB

blocked lines

I can't remove the pipes without a mess because there aren't and valves or unions.  The blockages that I think that I've found are at different locations, like, in an elbow about 8 inches from a radiator, 15 feet down a pipe that runs across the basement, right in the middle, along a riser, etc,  All of the areas seem different.  The boiler shuts off on safety because of the excess pressure so I haven't been able to check everywhere yet.  All I know is that the radiators do not get warm at all in most of the home.  What I am hoping for is someone to suggest a way to clear the lines without destroying the home.  The gentleman that lives there is 88, has oriental rugs, lace curtains that his wife bought, Victorian furniture, etc.  The reason that he has been cold for the last two Winters is because he didn't want to cause trouble for the other two plumbers and to be a pain to his family...just a little background.

JStar

First things first.

Are there main line vents, and do they work?

JohnB

vents

Yes.  There are two main vents and the were replaced with the boiler last year, so I assume (there's that word) they work. 

JStar

What if...

...you take the main vents out. Will the steam make it to the open pipe? Is the boiler cycling on pressure? Have you cleaned the pigtail to make sure it isn't short-cycling?

JohnB

vents

I haven't clean anything yet.  The boiler never did heat any more than two of the radiators, just like the last one.  The pigtail may be dirty, but I don't think that the unit would run at all or at least for the ten minutes that it takes to heat the lines until the blockages.  I will clean everything, but I am looking for a way to clean the pipes without cutting everything apart and making a mess in the home.