Water retained in the new radiator air valve

AlooLaw

I replaced two heat-timer quick vents with Maid-o-Mist steam radiator vents (type 4 and D each) about 10 days ago. They were good for the first a couple of days but become slowly responding to heat thereafter. unscrewed them and discovered water was trapped inside both vents. I believe water trapped inside blocked the air out channel until the steam pressure become high. Pulling out the water was easy but once or twice a week certainly become annoying. Anyone knows the root cause in my gas heat steam system?

Abracadabra

wet steam?
what pressure is boiler achieving during a cycle?
pictures of near boiler piping?
radiators pitched properly?

D is most likely way too fast a vent.

AlooLaw

Thanks Abracadabra. Here are the info:
I believe it is wet steam.
The low pressure meter show cut off at ~1.2 psi during cycles.
Radiators in question are leveled (0 degree).
The pictures enclosed show the right side, left side and the back of the Weil-McLain boiler piping, which is at least 26 years old.

It normally takes 12 - 15 minute of boiling before the 2nd floor radiators to start felling the hot steam in the inlet areas. It may take 20 minutes if water is in the radiator valves.

Abracadabra

Wider angle picture of the boiler showing all piping around it, especially the steam piping above it?

Is this something that just started happening recently after you replaced the radiator vents or was it happening before?

Has any new work been done?

Replace both radiator vents with #4 or #5 and add more main venting if you don't have sufficient. Can you find the main venys and take pics?

Which WM boiler is that? I think I see 3 main steam takeoffs from the header. I think header looks smaller than I'd like though.

When was vent damper removed and why?

The vent on the right that comes from your hot water heater maybe? That looks pitched wrong.

The 0-30psi gauge is useless. add something like a 0-3 psi gauge for a better reading.

Fred

Also, while the Pressuretrol may or may not be set correctly (Cut-in @ .5 PSI and Differential @ "1" (white wheel under the Pressuretrol cover), that Pressuretrol is probably toast anyway. The pigtail is upside down and likely let steam get to the Pressuretrol. That loop should hold water and prevent steam from getting to the Pressuretrol.

AlooLaw

Thanks for looking into the issues. There was no new work to the heater being done for the passed 15 years. I have just change two radiator valves.

I have noticed some water in the radiators before. But this time, two brand new valves trapped water in several days of usage caught me attention. There was not a lot of water, but enough to delay the heat coming.

There are two sliding doors in the way while I took the pictures yesterday. I took the door off and took a few more pictures today, hopefully they will provide what you want to see. There are 4 main steam takeoffs from the header. Let me know if you need more.

I changed a couple of main pipe valves in about 18 years ago. Though I have drop ceilings they were difficult to find and reach. It may take me a while to find them and take pictures. I suspect that there may be some issues there, too, I heard some water pounding several days ago in the area of one main pipe valve at the beginning of the heating cycle.

The vent on the upper-right of the 1st pic from yesterday is the vent for the NORITZ N_0751 tankless water heater. Its manual said the trimly end should be lower than the heater end so that the condensation, if there is any, will not run into the heater. The real pitched angle is about 1" in 2 ft. It looked more just in the picture.

Abracadabra, you are absolutely right on this: the 0-30 psi gauge is not proper for this application. I was puzzling that for a long time. It was there when I acquired my house 23 years ago.

About 15 years ago, the control unit (in the 2nd pic below) was out of order. I could not find a matched replacement (no internet at that time) , and therefore replaced it with a unit without then vent damper control. This was why the vent damper was removed.

Fred, if the pigtail was up-side-down, I am wondering if the plumber who did the job was licensed (before I got this house). The Pressuretrol seems working though, I have monitored every once in a while for many times, the cutoff point is about 1.2 psi. But I failed to set it to 0.5 psi before.

When the water in the heater tank is cold, it will take about 18-20 minutes to feel the heat coming in the radiator on the 2nd FL. Is this too long? My nest 2G thermostat turn of the heat in 20 to 22 minutes, when 80-90% of the radiators are still cold, in the heat maintaining cycle. I believe I wasted a lot of energy. If my heating system 5 minutes faster, or the nest turn off the heat 5 minutes later, all my radiator will be 70-80% hot and that will be a big difference. I greatly appreciate if you could help me to diagnostic my heating system to become more efficient.

Thanks!

Fred

On a boiler that size, they really should have used both riser tappings out of the boiler to the main. Also, it looks like they reduced the header size to a smaller diameter from the boiler riser. In reality, the header should be at least one size larger than the riser pipe.
That pigtail is certainly upside down. That should be corrected.
When you replaced the two radiator valves, are you sure you got a good quality Steam valve? I've noticed some of the cheap imports have a cast lip on the inside, that might work ok for a hot water system but may allow some excess condensate to dam up in a steam radiator.

AlooLaw

The Boiler's BTU/Hr is 200,000. I have measured the pipe that out of boiler, its outside diameter is 3.5". If they do not match I probably have to live with it until next time the boiler is replaced.

So the correct pigtail setting for my case can be loop up instead of loop to left, or L to left then loop down then up? Is there any high restriction for the Pressuretrol?

It is a good question about the radiator valve. There are too many brands and types out there. I am really uncertain which one should be trusted. I have changed all of them to Heat Timer Quick Vent several years ago. Their failure rate in my case is about 10% in two years. This time I have tried two Maid-o-Mist steam radiator vents. Please see pic below. Please advise which brand shall be reliable. As Abracadabra mentioned, I should find some really good ones for my main pipes, too. But I do not know which ones to go for.

If the air vents that I am using are good ones, the culprit that causing water in the vent in a short period of time must be something else in the system.

Thank you.

BobC

What do you have the Heat-timers set to? If you set them too high you will have huge amounts of condensate and that is going to be a problem. You would be well advised to follow that well worn maxim - vent the mains fast and the radiators slowly.

A 3" main is going to require a Gorton #2 (or it's equivalent for every 10 to 12 ft of length is you want to vent it quickly.

Bob

Fred

You want the loop part of the pigtail to be at the bottom. That way it will hod water and protect the Pressuretol from steam. The Pressuretrol can be as high as you want it, it just should not be below the boiler water line.
I think a lot of guys here have good luck with the Maid-o-Mist radiator vents. Gorton makes some good ones as well but they are not adjustable. Hoffman makes the 1A, which I use with good luck. They also make a #40 which is a slow vent that work very well on most radiators but larger radiators and ones very far from the boiler would probably be better served with the 1A that you can adjust.
Most people really like the Gorton #2 for main vents. They ar the astest vent on the market, as long as you have 7 or 8 inches headroom to mount them. They are a large vent. The Gorton #1 is a smaller Main vent that dosn't require the headroom but it takes about 3 Gorton #1's to equal the venting capacity of a Gorton #2. Hoffman makes the #75 which is also a very good main vent. It is about 5.5 inches tall but again it takes 2 Hoffaman 75's to equal a Gorton #2.
Water spitting from a vent, if it is a good vent, is typiclly caused by wet steam (near boiler piping isn't right), a radiator that isn't pitched correctly, or high steam pressure. Make sure your Pressuretrol is set for .5 Cut-in and a differential of "1" and make sure the pigtail it is mounted on isn't clogged with gunk.

SWEI

They make straight pigtails for that.

ChrisJ

It's normal for a vent to hold some water in the bottom, but not much.

Any bit of the housing that is below the nipple will be trapped but it won't impede venting at all.

AlooLaw

Hi, my newly upgraded Windows 10 was broken and I have to roll back to my good old Windows 8.1. It wasted too much of times.

Abracadabra, Fred and Chrisj:
I have managed to take apart both the pigtail and the horizontal pipe and cleaned their internal dirt. The blowdown unit seemed to be clean and the floater inside seemed working. I also installed a 0-5psi new gauge, adjusted the pressuretrol to its lowest setting with 1 differential. Now the heating system seems to operate more correctly. It start to cut-out at 1.3 ~ 1.4psi after 43 minutes of burning (from a cold tank), and cut-in at exactly 0psi about 2:19 minutes later. It took about 3:50 minutes to reach 1.4psi and cycle again. Therefore, after 43 minutes of burning, the system will continue to provide full heat to all the radiators in the house with about 38% of energy savings. This scenario will apply to every the cold morning when it needs to heat up the house several degrees before the family waking up.
However, I still did not get a chance to look at the main pipe vents yet. I believe that will result more savings.

Hatterasguy, Fred and SWEI:
Water will flow into the horizontal pipe connected to the Gauge and the Pressuretrol if the water level is at 1/2 of the glass or higher and the pigtail prevents the water flowing back. Actually the pigtail is coming out from the blowdown unit which is usually full of water. So I think the gauge and the pressuretrol are safe. After I cleaned the pigtail and the connected horizontal pipe, I fill water into the horizontal pipe before installing the new 0-5psi gauge, just to be safe.

BobC:
When you ask how high the Heat-timers set to, do you mean its opening size? I let each them fully opened, with the intention to get hot steam arrives faster. I believe your suggestion of “vent the mains fast and the radiators slowly” is the absolute right thing to do. But I have not have time to run through the mail pipe vents yet, they are above the dropped ceiling and some of are above the fixed ceiling and hard to reach. To me, that is a big project and It may take me a while but that will be my next one to tackle.

SWEI:
Many thanks for the link for the pigtail. It will make my life much easier in case I need it in the future.

BobC

Using the heatimers fully open is not usually a good thing to do, venting that fast on a radiator can lead to too much condensate.

Try turning them down to see if things change.

Bob

AlooLaw

Hi BobC, The weather in NYC is turning warm early but I will try what you said once the temperature drops again.

Could there be other causes for the radiator vent condensation, since the brand new #4 Maid-o-Mist steam radiator vent, after putting in use for several days, has the water in it, too? The water does delay the heat coming. The heat comes in 18-20 minutes if it is free of water, with condensate it takes 30 minutes. The radiator in question is leveled (no pitch).

ChrisJ

Steam turns to water when it hits any surfaces cooler than it.
This obviously includes the radiator, who's primary job is to turn steam into water.

It also includes the vent it self.

I had problems with this for years until I realized it was normal, this is why vents are designed to drain.

I've had the best luck with Gorton's regarding this. MOM vents are almost identical to Gorton so I'd expect similar results, but perhaps your best bet is to swap a Gorton in and see what you get?

I run Gorton's with no problem at extremely low pressures, pressures that caused endless issues with Hoffman 1A vents getting a tiny drop of water in the vent orifice that would act as a plug and stop the radiator from heating until I blew it out with a can of air.

AlooLaw

Hi ChrisJ, many thanks for the info. Better condensation resistant vents are the ones that i should employ to minimize the unwanted steam blocking at starting of the heating cycle.