2 pipe first floor + 1 pipe second floor

Bartos

I have 3 baseboard radiators with air vents that are 2 pipe. These are on my first floor. My second floor has 2 single piped radiators. All the radiators have air vents. My return lines on the 2 pipe system have check valves of some kind but nothing on the radiator itself. I was away for a year and my ex wife never draining the system just added water every week. One of my main vents was spitting and hissing so i replaced it. Thats where my troubles began. I replaced all the vents in my house since they are cheap and my house wasnt balanced. Since then none of my vents are closing. They all hiss. I adusted my pressures down to roughly .5 and 1.5 and still get the problem. Ive asked a few guys for help and they are all lost cause no one understand why i have 2 pipes on a 1 pipe system. Any advice would be greatly appreciated. Thank you.

JUGHNE

Where does the 2nd pipe (return) go to? And is there a trap on the end of the BB heater?

Pictures of the end of the heater with "check valve" please.

Fred

You need to post some pictures of the boiler, the piping around and above the boiler, a pic of the two pipe radiator and a pic of the one pipe radiator. Also it would be good if we could see a picture of the main vent(s) and where they are located.

Bartos

I only got 1 of the base board radiators cause the other 2 are over 12ft but set up identical as the small one.

Bartos

Here is the check valve on the return lines of the 2 pipe part. No check valves on the one pipe. I have no traps or second shut offs on the return part of the baseboard radiators.

Jamie Hall

Oddly enough, the boiler piping doesn't look that bad...

That one main vent type thing (picture 171301) probably is way too small...

However, first things first. Check that the pigtail on the pressuretrol isn't clogged, and that the opening on the bottom of the pressuretrol is, in fact, open. No vents should hiss if the boiler is really shutting off at 1.5 psi. It may be that the pressuretrol is out of whack -- not unheard of -- or it isn't sensing the actual pressure.

As to vents. The radiator with the vent at the top -- picture 171436 -- that vent is in the wrong place. It should be partway down, like the other radiator. Baseboard on steam is a difficult combination. What I think I'm seeing -- I'd have to be there to be sure -- is that there is a return at one end of the baseboard and a feed at the other -- and a vent. It really is a vented one pipe situation, but the additional return is very helpful with baseboard steam. Now the check valves... not sure why they are there. They may be needed, though. If the baseboards are heating, and there isn't hammer, I'd postpone thinking about them...

Fred

I have several observations but I will start with a very likely cause for your problem: That being I see your Pressuretrol is mounted on a pigtail on the 1/4" tapping on top of your low water cut-off. That is not, by itself a problem except, that pigtail should be taken off and cleaned annually. When it is mounted on that McDonnell Miller #67 Low water Cut-off, I have always found they get clogged and need to be cleaned out at least twice a heating season. Take that pigtail off and replace it for two reasons. The loop part of that pipe should hold water to protect the Pressuretrol and gauge from steam You need a straight pigtail configuration so that the loop will hold water. Having said that, I'm betting that looped pipe is clogged and your Pressuretrol can't see the steam pressure and letting it get out of control, causing the vents to hiss and spit water.
Other things I noticed that should be addressed for a better running system:
- I see the radiator vent on the one radiator is mounted on the top of the radiator (the tall radiator) Vents should be mounted about half to 2/3's the way up the radiator to vent properly.
- I also see your Main vents are way to small for your mains. You need to have larger vents installed on the mains to help reduce pressure and to get steam to the radiators faster where it can heat the house.
- There are some single pipe systems that have two pipes and vents and even two pipe systems that have single pipe radiators. In your case, as long as that return pipe drops down into a wet return (in the basement a pipe that runs at floor level, below the boiler water line) it should still work fine.

Bartos

I cleaned the pig tail and checked the pressuretrol. Looking at the radiator with the vent in the wrong spot. It looks like ive got a plug about 1/3 of the way up the side. Looks like they tapped it to put a vent in. I believe the second main vent youre refering to is a vent-rite #35. My local supplier gave me it when i brought the old one in.

Everyone thats looked at it hasnt really found anything wrong with it but no one gets why i have 1 pipe and 2 pipe together. My 2 pipe go to dry returns just an fyi.

Bartos

all my returns are dry returns till it hits my hartford loop.

Fred

Bartos said:

all my returns are dry returns till it hits my hartford loop.

I would think that means steam can enter those radiators from both ends, especially with the vents on them. I doubt that's the best approach. Also, I see you say you cleaned the pigtail, did you also clean the tapping in the top of the LWCO? That tapping will clog also and make sure the tiny orifice in the Pressuretrol (inside where it mounts to the pigtail) is not clogged. Do change that pigtail to one that will hold water in the loop. It may also be that the Pressuretrol is fried from years of steam hitting it.

Bartos

I had not thought about the pigtail being wrong but makes a lot of sense. I checked and cleaned everything checking for and blockages. My pressure gauge is on the same line as my pressuretrol and i do get pressure at the gauge. Ill try and grab a new pressuretrol and pigtail tomorrow after my roads get plowed. Fingers crossed thats the problem. Thanks.

Ironman

That looks like a two pipe air vent system. They were done before traps were invented in 1903.

You find an article about them in the "systems" part of this site.

Here it is:
https://heatinghelp.com/systems-help-center/two-pipe-air-vent-steam-heating/

EBEBRATT-Ed

It may have been there for 50 years but whoever piped the baseboard didn't have a clue.

My guess is it was all originally 1 pipe and they took radiators out and put baseboard in. Baseboard won't work on one pipe unless it can be pitched which is ugly as it needs a return pipe to drain it.

A few options are91) install traps on the baseboard or (2) (what I would recomend) disconnect the baseboard return and drop the pipe down and then back up to make a loop seal as described in LAOSH (dans book)

Bartos

You are 100% correct on this being a 1 pipe system first then converted over. My worry with putting traps on the 2 pipe part is will it screw up my 1 pipe radiators upstairs. I do like your loop seal idea though.

EBEBRATT-Ed

Disconnect the return and drop a new return down to the basement floor and then come back up. Your supposed to pipe the new return into the bottom of the return main. This pipe will fill with condensate and make a seal between the supply and return. You have to run a fairly low pressure to maintain the seal.

Now, if the three baseboards are reasonably close to each other you could drop returns from the three baseboards down into a common return line. This line must be below the boiler water line. You could then pipe this 1 return line back up into the bottom of the dry return or take it back to the boiler as a wet return