Restore crossover?

TKPK

I have a 34 YO WM EG65 boiler operating in a vapor system that is now behaving very nicely and operating at 1-2” of water, single 15-16 minute burn cycles every 65-80 minutes with 30F outside, 66F T stat setting. I have calculated EDR and the boiler is well matched.

I already know I messed up but it was 15 years ago … there used to be a crossover connecting the midpoint of a main to the start of a return.

I’m wondering if I should restore the crossover and what can I expect if I do. I do not remember there being a thermostatic trap at the return end of the crossover but there must have been?

34 year old Weil McLain EG 65 in a 100 year old house

basement main (red) and return (blue) runs, there are air elimination valves on all of the main and return lines at the boiler. I have replaced or added more venting capacity as some of them were barely or non-operational

yes, I know I F’ed up. The old crossover used to come out where I have the Gorton #1 and paralleled the main and into the return after the 90. The Gorton #1 has sped up the steam a bit but I don’t think it is correct and the benefit is superficial.

The main takeoff and the return you can see above the pumpkin go to the attached garage and apartment above the garage. These are the coldest rads in the house by far. They get steam but never enough to get hot unless I have an extended burn. We don’t use the room much but I mostly want to protect the pipes. We use pipe heaters now to prevent it (after previous problems). I have installed a vent on the riser at the end of this line to reduce resistance with some benefit.

again, I know I messed up.

I have available D&B 1E steam trap and can restore the crossover. Before I do I wanted some validation that it makes sense?

I had installed the Gorton #1 at the split on Main2 because the end of Main 1 sees steam at 4 minutes and 2A and 2B at 6.5-7 minutes.

delcrossv

What venting do you have on the dry returns?

TKPK

dry return 1: Gorton #1

Dry return 2A: Gorton #1

Dry return 2B: Hoffman #75

all the return vents have this configuration with the 45s or 90s and expansion chamber

delcrossv

Which vent is from the non heating rads? Also, that's the main with the missing crossover?

TKPK

Hoffman 75 is on 2B which is also where the missing crossover was connected. Crossover connected main 2b right after the split to the start (in the basement) of return 2b

There are several radiators further down on that loop that are heating fine including the room with the tstat

The garage and apartment radiators are on a long riser and go through some cold space.

Jamie Hall

There will be no real benefit to replacing the vent with a crossover — although a bigger vent there would not come amiss. What may help — possibly a lot — is putting a vent at the end of the riser/runout to those cooler radiators, somewhere just before it connects to the radiator inlets. At least a Gorton #1.

TKPK

https://forum.heatinghelp.com/discussion/comment/1826822#Comment_1826822

I did this on one of the radiators and was considering on the other two. I had years ago put a radiator vent on two of them but I now understand they are not desired on two pipe steam systems.

Jamie Hall

Gets complicated. Some two pipe systems must NOT have any vents out in the field — just the vent or vents at the boiler. Others are built with vents on the dry returns at the boiler, but at the ends of the steam mains out in the wilderness.

That's what a vent on a riser really does — get's the air out of the pipe going to the radiator as fast as may be. But since it is before the radiator, any partial valve closure or orifice doesn't affect it.

If the system is the kind which has vents on the steam mains, then there's no harm to a vent on the radiator as well — but no value to it, either.