Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Steam coming from condensate receiver vent

Here we go...

I recently purchased a building heated by a 1 pipe steam system. Thanks to this great site for all the advice. It has helped a great deal.

Here is the layout of the system. The building is three stories plus a storefront basement. The boiler is at the storefront level. There are mains running down the 2 long sides of the building. The original boiler was in a pit below the storefront and all of the condensate gravity returned to the boiler. Sometime in the 60's the old boiler was buried and a new boiler installed at floor level. The problem at that point was the condensate needed to get back into the boiler. A condensate receiver and pump was installed. The condensate returns from each side of the building with a steam trap on each of the two legs before they enter the receiver.

Recently we have had steam coming from the receiver vent. The longer the boiler runs the heavier the steam pours out. Normally there is very little but if the boiler runs for a long period it steams pretty good.

Is this most likely a failed steam trap or is there another possibility? The condensate pump seems to work properly. When it runs the boiler level goes up. Is there a way to test the steam traps? They are Watson Mcdaniel FT-3.


  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
    First check the pressure

    if it's too high the condensate will flash to steam when it reaches atmopsheric pressure as it leaves the traps. Crank the pressuretrol down as far as it will go.

    If you still get steam coming out of the vent when the pressure is cranked down, you'll have to have the traps rebuilt. Parts are available for most traps, from Tunstall or Barnes & Jones.

    If that were my building, when it came time to replace the present boiler I'd open the floor up again, remove the original boiler and put the new one in the pit. This would allow the removal of the pump and traps, and the Dead Men would applaud.

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • AndrewJ.Staves
    AndrewJ.Staves Member Posts: 3
    Pressure setting

    Thanks for the response.

    The pressuretrol is set at .5 with the differential at 1. The gauge shows it cuts out around 2psi and back in around 1.

  • Jerry_15
    Jerry_15 Member Posts: 379

    Sounds like traps, but if your water level is getting high try restricting the feed off the condensate pump so it feeds slower. Alittle back-pressure on the discharge side won't hurt the pump, and may give the boiler time to catch up to the condensate return.
This discussion has been closed.