One pipe steam heating system condensate return.

RobC

<span>We are looking for a solution such as a condensate vacuum pump for one leg of our buildings ground floor one pipe steam system

condensate return line that used to easily flow into a float condensate tank

that returned the hot condensate back to our boiler.</span>

<span>The 5 ground floor apartments are only getting

heat when we put a shop wet vac on the return line manually, otherwise no

condensate comes out of the line and the apartments get no heat. Please advise

so that we can resolve this problem.</span>

Jamie Hall

If it used to work

and it doesn't work now, a solution like a condensate vacuum pump is just a bandaid.



First question: was anything -- anything at all -- changed about the piping -- either supply or return?  Or the boiler?  between when it used to work and now.  If so, figure out what went wrong.



If not, the first thing I'd look for is a partly clogged return here.  But a second possibility is that something is amiss with the steam main, such that water is pooling in it somewhere.  Can you trace the main, and find out how far steam does get?  Obviously it isn't getting to the radiators...

nicholas bonham-carter

shop vac for return

jaimie is right as usual, and very right in this case. this line has most likely sagged, causing a pool of condensate, which is preventing the air from escaping in front of the steam, or the main vent on this line is closed due to over-pressure, with the same result.

check your pressure with a good low-pressure gauge [gaugestore.com-0-3 psi]. try to get the pressure down to 1.5 psi [basic functionality], or 8 ounces [vaporstat needed for economy and comfort].

if you would like even more economy and reliability, try to cut that condensate tank out of the return and go with gravity. there are not many situations where you really need any sort of pump like that, and it is a service liability.--nbc

Brad White

Sagging and Clogging

Ah, the penalties of aging!

Applies to steam systems also.



That it used to flow freely says something sudden, a clod of rust, debris, scale, came loose or a build up that could be overcome suddenly has passed the tipping point.



I would suggest feeling along the line for where it runs cold once the system is warmed up (the return will be cooler but still warm and you may notice a sudden drop). At least to narrow down your search. You may find it handy to reconfigure the ends of this lowest return with tees and caps or full port ball valves on the end to make inspection and cleaning easier. But for that effort, direct replacement, even go up a size, may be a better bet. But finish the ends with a plug to allow later reaming.