Dunham system

Oak Park Electric

My first residential steam job-  1910 or so house, 2 pipe Dunham system, 60s (?) Sears Homart boiler, cold rad in 2nd floor bathroom.  Couldn't get pictures of boiler because HO was watching every move, but next to boiler is a HUGE cast iron thing called a Dunham Return Trap No. 8A.  Dunham Air Eliminator is up at ceiling.  Fortunately, that's not the problem.  The rest of the house heats fine,  just the one cold rad.  As you can see, it has a trap, and with the union loose it gets steam.  Seems simple enough, right? New trap.  But the room was remodeled, and the rad moved.  Original would have been on outside wall, this one is under the sink by the door.  So, question is - with this system, should it have a trap or did whoever moved it just put one in " because steam radiators have traps " . 



My area of expertise is larger equipment,  ( 150 hp steamer at work, last place I was at had 3  that were about 450 - 500 hp ) but I'm learning everything I can about small systems, and this is the place to do it.

Rod

Bump

Just to keep you up front. One of the pros will have an answer for you.

- Rod

gerry gill

oh, it needs a trap all right..

if you got steam by loosening the union, its either a bad trap or a sag in the return pipe holding water and not letting the air vent out. Going to have to remove that trap and repair or replace it..more than likely.

Jamie Hall

I'd second that...

but add that while you have the trap off, or at some convenient point, do check Gerry's comment on the sag.  When it was moved, it is all too possible that the return line didn't get pitched quite right...

Oak Park Electric

Thanks guys

Thanks for the bump, Rod.  Also Gerry and Jamie for the response.  I was afraid that it could be a line pitch issue.  When I go back, I'll remove the trap and check it, also probably put a hose on the condensate line and try to blow through.  I sure hope its just a bad trap...