No heat in one steam main

kevinjames79

Hello all

i have an urgent issue. With the start of the winter season, i turned on the heat and there is a problem. I have 2 steam mains. When steam is created one main gets heat quickly but the other one does not. The second main only gets heat if i keep the heat running for a long time and increase the psi. Also i hear some noise in the second main but minor but feel like water but its very minor. Is there water in the second main?

I checked the pitch and it has slight pitch going away from the boiler. So i increased it a bit but nothing happened.

i am desperately in need of ideas here. IF there is water in there, then how do we remove it? If not then what it could be?

why second main is not heating?

nicholas bonham-carter

What sort of main vent is on each main?
The main vents do most of the system air removal, each time the system fires, and the radiator vents take care of the radiator, and it’s piping, from the main.—NBC

newagedawn

need pics of the main, is it 1 pipe or two pipe? but sounds like the second main has a bad air vent or no vent at all, fallow the second main to the end to see

JUGHNE

Is this the system you had posted about in 2017?
Did you add main vents?

kevinjames79

JUGHNE said:

Is this the system you had posted about in 2017? Did you add main vents?

Yes. Main vents were replaced in 2017. New ones are big mouth.

kevinjames79

JUGHNE said:

Is this the system you had posted about in 2017? Did you add main vents?

It is a one pipe system.

kevinjames79

Btw. Boiler has been cleaned multiple times and also skimmed.

EBEBRATT-Ed

Check the pitch if you think there is water in it.

All steam mains have a way for water to get out. They have to be pitched.

1. Some mains are counter flow they are low at the boiler and pitch up away from the boiler the condensate runs back towards the boiler and drips down into the boiler return at the boiler. These are less common
2. More common is for the supply main to rise up from the boiler to it's highest point and pitch down away from the boiler. The condensate goes to the far end and then has two choices it returns to the boiler:
1. through a dry return that is run above the boiler water line or
2. the return drops down below the water line (a wet return) and the wet return usually goes under the floor or on top of the floor or along the wall but always below the boiler water line

And make sure you have the right vents and they are working

JUGHNE

What does this main have for condensate return?
Does your boiler water level vary with water auto filled or over filled?

kevinjames79

EBEBRATT-Ed said:

Check the pitch if you think there is water in it. All steam mains have a way for water to get out. They have to be pitched. 1. Some mains are counter flow they are low at the boiler and pitch up away from the boiler the condensate runs back towards the boiler and drips down into the boiler return at the boiler. These are less common 2. More common is for the supply main to rise up from the boiler to it's highest point and pitch down away from the boiler. The condensate goes to the far end and then has two choices it returns to the boiler: 1. through a dry return that is run above the boiler water line or 2. the return drops down below the water line (a wet return) and the wet return usually goes under the floor or on top of the floor or along the wall but always below the boiler water line And make sure you have the right vents and they are working

I have the wet returns. 

Is it possible that the wet returns are full and thus water in main is unable to go to the wet return? 

I see the wet return coming back to boiler. It has pipe going into the boiler. This wet return is on the floor. How does the water in this wet return go up the boiler?

EBEBRATT-Ed

@kevinjames79

Picture this. The boiler and all the piping are empty and the boiler is shut off. You open the valve to fill the boiler and in time you see water in the gauge glass half way up. You wet returns have also filled up to the level of the gauge glass. So if you took a ruler say the gauge glass half full is 30" above the floor and then you walk out to where the return from you steam main drops down into the wet return and measure up 30 inches that's the water level in the return.

Now you turn the boiler on and steam enters the cold steam main. This causes some steam to cool and condense back to water. This water or condensate follows the pitch of the steam main and drops down into the wet return. As one drop of water enters the wet return it pushes one drop of water back to the boiler.

If the boiler makes stem pressure this changes slightly but for practical purposes thats how it works


If you have water in one steam main it could be a plugged wet return. Does the other steam main have a different return or the same one??

JUGHNE

Or imagine a 5' length of soft clear tubing, fill it almost full of water. Leave 3' of it lay on the floor.
Imagine, (or actually do it) adding a little water in one end, the opposite end of water will rise.
That wet return always stays full of water.

That water is usually full of sludge and maybe nearly blocked, keeping the water from returning at the boiler and backing up on the steam main end.
Often the underfloor returns rust thru and you continually lose water causing the auto feeder to keep adding water without you being aware of it......does this happen.
You could be both plugged and leaking.

Pictures of where it comes out of the floor on each end would help.
Also pictures of both returns...both ends.

EBEBRATT-Ed

@JUGHNE
I think in one of the OPs posts he says the wet returns are on top of the floor which is good.

Weather is cost effective to try flushing it or just rip and replace with copper is another issue

kevinjames79

EBEBRATT-Ed said:

@JUGHNE I think in one of the OPs posts he says the wet returns are on top of the floor which is good. Weather is cost effective to try flushing it or just rip and replace with copper is another issue

Thank you guys

is there any way to flush the returns?

my problem is all the pipes in the basement are behind the sheetrock walls.

JUGHNE

How about the ones at the boiler?
Can you show us?

STEAM DOCTOR

Clock the gas meter. Maybe flame is undersized and you aren't getting enough steam. 

newagedawn

sometimes releasing the air to quick creates a vacuum so no steam can run, try changing the big mouth to something alittle smaller to allow air out at a slower pace!!!!!!!

JUGHNE

Wouldn't a vacuum pull steam towards itself.....thinking of vacuum systems?

Jamie Hall

JUGHNE said:

Wouldn't a vacuum pull steam towards itself.....thinking of vacuum systems?

yup.