Questions about my steam system

Jay4334

Could someone tell me how hot the return main should be? The first 30' of the return main is pretty much warm to the touch...As I mentioned previously the is about 95' of steam main running around the perimeter of my basement gradually sloping down and the return line follow the same path/slope as the steam main. The first half of the return main is not that hot, however the last 30' of the return main is VERY hot, and will burn if touched. Out of the 10 radiators in the house 6 of them are on the last 30-35' of the 95' loop. Is this the reason this section is SO hot? The return pipe is 3/4" all the way around, but the last 15-18' was replaced with 1" pipe when the new boiler was installed. Any ideas?



I have a decent temperature difference between main level and 2nd floor. Ive read with a two pipe system you can control the heat to an extent by closing the inlet valve on the radiator slightly. Would this just allow less steam/heat upstairs if I partially closed valves on 2nd floor and force more steam/heat to the main level radiators? Or, is it just heat rising, and closing the valves upstairs will only help lower the warmer temp upstairs?



Lastly, could someone tell me what type of trap I have on my radiators(attached a picture). What are my other options for replacing traps? I have one radiator that does not get hot beyond the inlet pipe, and another only heat up about half the radiator. Of course they are both nearest to the thermostat which causes the boiler to run more than it needs to. If close the radiator inlet valve, can I detach the bad trap and keep the system running? Thanks again

Jamie Hall

Honestly I don't know

what type of trap that is -- hopefully one of the real pros will jump in and tell you..



However, I will say this.  If you have a section of return which is really really hot, it almost certainly means that one or more traps have failed open and are letting steam through.  This will upset the balance of the system rather badly, if nothing else.  So you really do need to know what kind of trap it is, so you can fix it.  Sorry about that.



It is quite true that you can control a two pipe system with the radiator valves.  Just close them down until things seem right.



I might add that if your pressure is low enough (ounces, not pounds) you can, until you get the misbehaving traps under control, partly if not completely solve the problem by close the valves on the radiators with misbehaving traps almost completely; the trick is to set them so that the radiator gets hot almost -- but not quite -- all the way across when the system is running for a longish time.



And I would try that first before anything else.  You might find that the radiators which didn't heat now do, with the steam out of the return.

RoiiRaz

Main or Rad Trap?

Are you asking about a rad trap or a main trap? Do you have traps at the end of your mains?

Jay4334

RoiRazz

The pictured trap is on the end of each radiator....I also have a F&T trap on the main

RoiiRaz

Main trap...

How's the temp on the other side of the main F&T trap?

Jamie Hall

An F&T trap

on the main?  How is the main vented?

JStar

Thermostic trap

Rad trap might be a Spirax-Sarco. Can you remove it to look for a model number?