Balancing

joshua2002

I have a 100+ y/o system at a church operating with a 80s burnham. Up until last year the system has ran fine but as of last season we’re experiencing issues. Main church area no longer satisfies @70*F and main entryways and certain areas are reaching temps +90*F. We’ve been slowly rehabbing the system over the past few years replacing all steams traps and fixing all leaks and as of last season were completely done with repairs. Boiler is operating at 1/2lbs. It seems as if the side of the building that first receives heat being completely blown by. Where the run dead ends before it makes its return back towards boiler is comparable to a sauna more than a church Any ideas on what could be going on so suddenly?
6” header leaving boiler to supply building
1/2” lbs of steam pressure

All new traps and all leaks fixed

All piping insulated (for the most part)

dandub1960

I'd start by checking if the main is heating fully. Then look at your main vents. I know that doesn't explain the far end rads getting all the heat, but if there is branching maybe some sections are air locked? Any zone valves closed off?

mattmia2

How are the mains vented? Is a crossover trap from a main to a return failed open and putting steam in the return and closing all the traps along that main so that those radiators can't vent and heat?

Are the returns steam hot anywhere, are they basically the same temp as the supply mains?

JUGHNE

Perhaps now that all the leaks are fixed, the air can not get out as it used to.

Any air vents at the end of main or is there a receiver pump that might not be piped correctly so as to vent air?

mattmia2

https://forum.heatinghelp.com/discussion/comment/1869128#Comment_1869128

or crossover traps that were missed when the traps were replaced. A failed closed crossover trap for the section that isn't heating is also a possibility.

EBEBRATT-Ed

Its probably a trap issue of some sort. Start the boiler up when cold and follow the piped. Something changed. The work that was done is likely the cause. Maybe they gave you some wrong trap elements.

joshua2002

https://forum.heatinghelp.com/discussion/comment/1869119#Comment_1869119

the main is 100% getting heat. Also I have yet to find one vent in the system and let me tell you I have been in every part of this building even places the maintenance didn’t know existed. This is a two pipe system w two indirect coils they use as well tied into the duct work. This system has also been converted a few times to my knowledge. It started as with a coal boiler which was abated in the 50s along with being vacuum system up until the late 80s.

joshua2002

I completely changed every single trap not just the elements but the complete trap and adjacent piping. This system was super neglected over the years. The only traps I haven’t been able to get to are the bi metallic traps tied onto return @radiator in wall which subsequently are also the radiators that don’t get hot

joshua2002

Also, the building used to be zoned but the valves have since been abandoned along with the thermostats and all wiring. Mind you this building is 100+ years old so it’s underwent some changes and seen many phases of development with steam heating. My thought was installing thermostatic valves @ radiators in the rooms that are getting so hot as these rooms used to zoned. Abandoned zone valves are still in place but are throttled wide open.
two 3” zone valves and one 1 1/2”

joshua2002

The section of radiators that are not getting heat are supplied directly from the 6” main. There is a wall that has 5 radiators and each one progressively gets colder as you go down the run. However, the rads that come before it on the run and after all receive ample heat. The rads downstream of these 5 are actually getting so much heat it’s unbearable to be in the room. These rads are in the vestibule area of the church that is completely made of stone and has four entryways all solid wood church doors that create poor seal. My thoughts on why there are so many radiators in this one room all being 12 section column radiators is because the doors would constantly being opened during the cold winters we once had (Grosse pointe park, Mi) 100 years ago. Or doors being left open for that matter. So many things to hypothesize and no record of anything.

joshua2002

https://forum.heatinghelp.com/discussion/comment/1869119#Comment_1869119

I have not found one single main vent on this system.

mattmia2

in 2 pipe systems the mains and the emitters typically vent in to the returns and the returns are vented. If it was a mechanical vacuum system the only vent was likely the vacuum pump on the return. It should be open or have a large vent on it now. If someone plugged it, that is part of your problem.

if there is steam in the returns it will likely prevent the radiators on that return from being able to vent and heat.

Failed closed traps will obviously keep the emitters from heating but a single failed open trap can keep many emitters from heating.

If the system pressure was cranked way up emitters with failed closed traps may have been heating somewhat, the higher pressure will compress the air in the emitter and allow some steam in, then that steam collapsing will pull more steam in so you can still get mediocre heat in an emitter that can't vent.

Barns and Jones or Tunstall likely can get you replacement cages for the traps you can't replace.

Return lines that were designed for mechanical vacuum may be too small or marginal without vacuum

Pumpguy

Can we see what type of pumping equipment is there now? Please show near by piping too. This will tell us how the venting is arranged.

Jamie Hall

"The section of radiators that are not getting heat are supplied directly from the 6” main. There is a wall that has 5 radiators and each one progressively gets colder as you go down the run. However, the rads that come before it on the run and after all receive ample heat. The rads downstream of these 5 are actually getting so much heat it’s unbearable to be in the room. These rads are in the vestibule area of the church that is completely made of stone"

Is there any hope you can draw a diagram of this section, including the main or sub-mains that feed it, any traps, and how the return piping is arranged? How does it tie into the mains and returns from the radiators downstream?