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cold return

I recently had a new gas fired W/Mc EG45 steam boiler installed. It's a one-pipe system, split into two mains, which I'll call "front" and "rear". After ironing out many bugs. , the system heats up very evenly, with no hammer. I've noticed that a 3ft section of the "front" return drip leg remains cold thru the entire cycle. This 3ft section is between the horizontal return piping down to the NWL (approx). The "rear" return is hot for the entire run, I suspect this might be the cause of a pressure rise after approx 40 minutes of firing. This condition has both myself and my installer baffled. I have new 3/4" air eliminators on the end of both mains and all new radiator vent valves. My installer's solution to everything is to keep adding cleaner, saying my system is dirty. Any thoughts on why just a 3ft section of piping in the entire system remain cold?

An additional problem developed today, system ran fine, but at the end of cycle, I noticed that the gage glass had actually gained water!, So I drained a few gallons off but the level in the gage glass never changed and the low water indicator light came on. So now I have no idea where my water level is. This unit is driving me nuts.  Help


  • Cold Pipe

    Not sure quite what to tell you. Trying to figure out a problem from a brief description isn't easy. If you drained several gallons of water and the sight glass hasn't moved, the passages to the glass are obviously blocked up and need to be attended to right away, You mentioned your installer "keeps adding cleaner" and this may have knocked some large chunks of "crud" loose. 

    As to the cold return and the high water level. Do you have an automatic water feeder? If so, where does the new water enter the system in relationship to the location of the cold return section?   Is the "cold section" old pipe and if so, is there any chance the pipe is partially plugged up?   Since your system seems to have two returns, I suspect that one is returning condensate where the other (the cold one) may not be or is returning condensate very slowly. If you have an automatic water feeder`this would make up the water initial deficit which when the slower condensate returned, raise the water level


    I would suggest you clean the sight glass and get it working.

    Flush your boiler several times till the boiler water is clear. ( I wouldn't add more cleaner)

    If I couldn't come up with a practical reason for the cold pipe, I'd consider cutting into the pipe and doing a physical inspection. Perhaps there is a main vent or fitting you can remove and run a piece of wire down the pipe to check for blockage.

    - Rod
  • cold drip

    is this a counter-flow system with no dry returns? if there is a dry return, try putting the main vents [big ones] on the dry return close to the point of transition to wet return. sometimes any bits of air remaining can expand, and become "a wild card" pressure-wise

    what is the pressure on this system [a good low pressure gauge may be needed--gaugestore.com 0-3 psi].

    why not overfill the boiler and see if by opening the site-glass drain cock, you are getting water out. otherwise you may have to do the most effective cleaning-skimming again. when all is clean, refill only with clear water IE. no squick/cleaner/purple squid ink, etc.-nbc
  • ddog777
    ddog777 Member Posts: 9
    cold return

    The system is a split main counterflow system, with gravity returns. The drip connections on both returns are new piping. However the return that remains cold was piped with a 90 degree turn in it to get around the exhaust vent. My thoughts are that a drip leg should be relatively straight down to the H-loop.

    I will be dismantling my gage glass and vales today, as I do suspect a blockage in the lower valve.
  • Cleaming and Skimming Article

    On boiling cleaning /skimming - There is a really good article in the June issue of Oilheating on Page

    20 by tech/training manager of Weil McLain


    which might be of help to you. You might also want to take a look at Rhomar Water Management

    http://www.rhomarwater.com/products/residential-steam-system/  While I generally try to stay away from using an additive,  I've used their product and it worked very well.

    I missed that it was a counterflow system. The cold pipe is a strange problem. Even with an air bubble, water should pass through it. Some sort of blockage is the only thing I could think of that might cause it.

    - Rod
  • ddog777
    ddog777 Member Posts: 9
    cold return

    Thanks Rod, The boiler cleaning article was very enlightening, and I gave a copy to my installer who seems bewildered.
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