Help! Wet Returned Clogged, Should I Start By Changing Trap On One-Pipe System Before Condensate Pu

David_53

Last year all worked fine, this year just started boiler and the condensate is not returning on one of the lines....unless I run the boiler straight for several hours...then the return pipe finally gets hot all the way to the condensate pump located right behind the boiler.



I have two main lines, one about 80 ft and one about 125 ft.  Both lines run back to a brand new condensate pump on my one-pipe system.  I think the condensate pump was originally added (before I was in the picture) to the system because one of the return lines is not pitched properly when it comes back to the boiler...it actually goes down under the basement floor and then back up at one point and then to the condensate pump by the boiler.  Or maybe the A Dimension is slightly off and there is not enough pressure to bring the condensate back so they added the pump, I'm not sure. But this setup has worked relatively well for years....until now.



So the part of the pipe that goes down into the basement floor and is buried seems to be clogged because when I run the boiler only one of the lines is returning condensate. One line is working fine, the pipe is hot all the way to the condensate pump. The other line that is partially buried under the floor must be clogged with sediment because even when I run the boiler for 45 mins to an hour the pipe never gets hot all the way to the condensate pump. Even thought the line that works returns condensate and the pump brings it back to the boiler, the automatic water feeder has to come on because the other line does not return any water...unless I leave the boiler on for 2 hours straight...then it is somehow able to makes its way back.  I don't want the water to backup into the radiators upstairs and I don't want to keep introducing fresh water into the system or running the boiler for long periods of time.   But its starting to get cold and needless to say I need to start running the boiler regularly. It is a big unit, 6 chamber  oil powered Weil Mclain Model 80.  I don't know much about steam or plumbing, just what I have been able to learn reading posts on here and in Dan's books.



My Plan:



I spoke to my oil guy and he said first change the trap on the line that is cold, before the condensate pump (I have two traps, one for each line, as seen in pic) and see  if that helps by creating suction to bring back the condensate. The trap (I think that is what it is called) right at the end of the main line before the condensate pump looks like it is ancient (see pics). I'm sure it is clogged with tons of rust/crap that has built up over the years.  I can't read any markings on it. Can anyone provide me with a link where I could order a new one? Does anyone know from looking at the picture, what I should replace it with?



I'm thinking change the trap, and if that does not work I just need to dig up the buried pipe and replace it.



Any thoughts, would be greatly appreciated! Oh, and fyi, after these pics were taken, I unplugged one of the openings on the condensate pump and added a vent....just to be safe.

David_53

another pic

pic

nicholas bonham-carter

slow return

i suspect that there may have been a problem with the buried return line, and that the condensate pump was added as a quick, temporary fix. can you run a new return line an inch above the basement floor? if there is a plug in a buried line, then the rust-holes are unfortunately not far behind. any muck which is sucked into the rust holes will then quickly destroy the pump. the slope of the return below the boiler waterline is not important.

when you do this re-piping, why not remove the pump and traps and go with gravity. steam boilers are designed with the volume of water needed to fill the radiators in mind, so i don't think you will run out of water.

in addition, the addition of water by pumping, is not as perfect as gravity, as there could be some thermal shock as the big pump kicks in, pushing a large amount of water into the boiler.. there could be some uses for a pump, such as in a system with out buildings but only 1 boiler. the returns from the outbuildings would need a pump.--nbc

David_53

Thanks!

Thanks Nicholas! I kinda figured changing the line would be necessary.  I can't put it above ground because it has to travel across a path in front of a garage door.  I would prefer to keep my current configuration with the pump, because  I just spent a nice chunk of change on this new condensate pump and to have it installed, and if it has always worked before now, I think maybe I should not mess with it more than I need to...to just get it working again.



I found what you said interesting, "the slope of the return below the boiler waterline is not important." I'm just trying to get my head around why? If I have a condensate pump, water is not always in the entire wet return? Gravity has to take it to the pump...so wouldn't it be better for the pipe to pitch towards the pump?



Aside from that, I was just reading page 174 of The Lost Art of Steam Heating and now I'm wondering if the inlet steam trap before the condensate pump is even necessary?  Granted it has been there forever, but if my mainline has a few Gorton 2's  on it, do I even need a trap before the condensate pump? I was just looking at replacements traps, which I think are $600+, maybe I can just eliminate the trap? The condensate pump is vented anyway? And then if that does not help at all, I go and change the return line that is clogged?



Like I said, I don't know much about plumbing or steam, so please excuse my ignorance!

David_53

hmmm

On page 174 of The Lost Art Dan says avoid at all costs a double trapped return...He says don't try to get away with one MASTER trap at the inlet of the receiver", but since I have a one pipe system, this is the only trap I have....I just have the main vents out at the end of the line...so I'm not sure what he is saying would apply to me? Maybe I do need the trap before the condensate pump. I'm confused!

Steamhead

What you need

is a False Water Line before the condensate tank, instead of those master traps.



But I'll bet there's a way to change that system back to gravity return. If so, you can sell the pump, tank and traps on eBay.



Where are you located?

Rod

Buried Return

Hi-  Nicolas is correct. If it is below the boiler waterline slope isn't all that important. Think of a garden hose filled with water that has  one end higher than the other. if you add water to the high end, a same amount of water as that added with flow out the low end of the filled hose.  The big disadvantage of a buried return such as yours is that the pipe being in the soil will corrode over time and the buried loop acts a s a trap for any dirt /"crud" circulating through the system. As Nicolas mentioned it is probably time that it is due for replacement any way. I've attached a sketch of a setup with which you can occasionally blow up the sediment trapped in the buried loop. You could possibly install the necessary valves in the present buried line any try flushing it. If you do this I would set up the valves etc with unions so that they could be easily converted over to the buried new line when that becomes necessary.



Condensate pump - I would really question whether the pump is really necessary. If your system was a two pipe system as there is no residual steam pressure available, the "A" dimension is much higher than on a single pipe system. In your replies it seems you are familiar with the concept of the "A" dimension so I would really take a look at this subject and see if you could eliminate the condensate pump all together as this would greatly simplify your system which makes it more reliable and saves electricity and maintenance costs.

- Rod

David_53

I'm in NY

Thanks for replying! What do you mean by a false water line? How do I do that? 

Steamhead

It's a way

to keep those old wet returns wet. Here's a link to a collection of Dan's articles- go to page 14 to read about the false water line they used in Boston's Old North Church.



http://www.heatinghelp.com/files/articles/798/33_61_145.pdf