Pigtail clogged?

mdeebs

I recently bought a house with a steam boiler (approximately 20 years old). This forum has been an incredible help in learning the ins and outs of my system. I know there are numerous posts on the site regarding plugged pigtails and pressuretrols, but I have not been able to find one that would answer my specific question, and maybe it's a silly question.

For a little bit of backstory, the boiler I have is a Burnham SIN6LNI-LE2, gas fired. It is piped as a singular main down the center of my basement with a dry return/Hartfield loop back to the boiler. There is a main air vent that is piped into the elbow that drops down from the supply main down to the return. We have one radiator in the house that hisses louder than any other radiator in the house, and I believe to be hissing much louder than it should be. When we first bought the house, when the heat would turn off, this vent would produce a whistle when the air was entering back into the radiator. We replaced the air vent on this radiator with a 1/8" angled variable vent from the local big box store. This solved the whistling, but now the hissing is actually even louder.

Last night I decided to pay more attention to the system as it was operating and realized that the 0-30 psi gauge installed on the side of the boiler was reading between approximately 6-8 psi. The boiler would cut in when the gauge lowered to 6 psi, and cut-out when the gauge read 8 psi. Obviously, assuming that the pressure gauge is accurate, this is much too high for the boiler operation. The pressuretrol on the boiler was set at approximately 2 psi cut-in with a 1 psi (lowest setting) differential. I removed the pressuretrol to see if the pigtail was clogged and I did not see any sludge on the vertical portion of the pigtail. I stuck a small piece of a wire down into the loop of the pigtail and did pull up some black water on the wire, so I went to try to remove the pigtail. The pigtail was screwed so tightly into the boiler that I felt like I would break the pigtail and did not want to take the chance with the current temperatures here in the Northeast.

I decided to see if I can blow into pigtail to loosen up anything that may have been stuck. I know it's not the best idea, but I was looking for a quick solution. So here is my question. I blew into the pigtail and at first heard some bubbling from the water within the pigtail. When I stopped blowing into it and removed my mouth, the air that I blew in was rejected right back out as if I had pressurized the pigtail. This would seem to indicate that the pigtail is clogged, right? I wouldn't think blowing into a clear pigtail would cause a pressure build-up like that.

I appreciate anyone that's stuck through the long post and again I appreciate everyone's knowledge on this site and willingness to help out all us homeowners.

Jamie Hall

Brave man. Pigtail water is goopy.... A better check than blowing is to open the top of the pigtail, as you did, and pour water into it. You should be able to pour water pretty continuously and pretty fast without it overflowing. If you can't, it's plugged.

That said, it's also possible that the 0 to 30 psi gauge isn't telling the truth. They often don't, and since the pressuretrol does cut out and cut back in, that may be misleading you. What is the pressuretrol set at? It should be bit above half a psi cut in, and about 1.5 psi cut out. The indicator scales are different, depending on the specific model of pressuretrol.

Pigtailscan be very hard to unscew, to put it mildly, particularly if they've been there for a while (as yours probably has). There is a chance that you might break it trying; quite true. Therefore... if you are going to try it, you should go to a nice plumbing supply store -- or even online -- and get a new brass one to have at hand before you try. For the moment, though, if you have an air compressor, you could also try just blowing it out with air pressure. 15 to 30 psi should be ample.

mdeebs

Thanks for your response, @Jamie Hall . I will try to pour water into the pigtail when I get home to see if it is clear. The pressuretrol setting was set for approximately 2 or 3 psi cut in with 1 psi differential. I understand that this setting is above and beyond where it should be for typical operations. I lowered the pressuretrol down to about 1psi cut-in but I don't think I saw an appreciable difference in the boiler operation. My house is a 25x30 cape with two bedrooms on the second floor so there is no need for higher steam pressures.

If the pigtail is clear, is it safe to assume that the pressure gauge is faulty? When I was messing with the pigtail, the gauge was reading 0 and slowly raised to approximately 2 psi and then continued on to about 8 psi at a higher rate. I assumed, maybe wrongly, that the pressure gauge was operating correctly.

Andy_N

@mdeebs I had the same issue as you and able to fix it with the helps from the people here. In my case the pigtail and the plate at the bottom of the pressuretrol got clogged and would not move, I had to removed all the gunk inside the pressuretrol adapter that connect to the pigtail before that plate move freely with a little pressure. The new setup I put in after make it much easier to monitor the boiler.

JeffM

Another way to check the pigtail is with a more flexible probe, I like a long plastic ziptie (stiff enough to push, flexible enough to loop through the pigtail).
If you blew all the water out of the loop, it's good to pour a little more in to isolate the steam from the gauge.

mdeebs

So assuming that the pigtail is free and clear, would the next logical step be replacing the 0-30 psi gauge to see if that is operating properly?

Jamie Hall

Don't replace that 0 to 30 gauge. Building inspectors and insurance folks want to have it. Instead, add a low pressure gauge -- 0 to 5 psi (Amazon has them) somewhere handy.

mdeebs

I think I may have found the culprit. I’m hoping for confirmation. At the end of the main where the pipe drops to the return, there is a main vent. That main vent is a USAV-883. The vent feels cheap and looking at the size of the orifice on the vent, it doesn’t seem like it’d be able to properly vent the main. I have a feeling that this is causing that radiator to vent all the excessive pressure within the system since it is acting as the main vent. Am I right with this thought process?

Fred

mdeebs said:

I think I may have found the culprit. I’m hoping for confirmation. At the end of the main where the pipe drops to the return, there is a main vent. That main vent is a USAV-883. The vent feels cheap and looking at the size of the orifice on the vent, it doesn’t seem like it’d be able to properly vent the main. I have a feeling that this is causing that radiator to vent all the excessive pressure within the system since it is acting as the main vent. Am I right with this thought process?

You are correct. That is basically a radiator vent and not one that should be used to vent mains. Also, that is a cheap, Chinese brand product that needs to be pitched. Use a Gorton #2 or a Barnes and Jones Bigmouth for your main vents.

mdeebs

> @Fred said:
> (Quote)
> You are correct. That is basically a radiator vent and not one that should be used to vent mains. Also, that is a cheap, Chinese brand product that needs to be pitched. Use a Gorton #2 or a Barnes and Jones Bigmouth for your main vents.
That’s what I was hoping to hear. I had been reading up on the Gortons and big mouths. That will be my next purchase. One other question I am hoping this is the answer to also is: would that still cause the boiler to be operating above the pressuretrol settings? I lowered the cut-in down to 0.5psi from 2 and now instead of cycling off at 8psi, the boiler cycles off at 5psi. Would the pressuretrol cycle the boiler off at 1.5psi regardless of the air that’s not being vented?

Jamie Hall

It should, so either the pressuretrol is out of calibration -- they can be -- or something else is going on.

Fred

It sounds like the Pressuretrol may need to be recalibrated. Here is the procedure:
If you see the pressure on the low pressure gauge go much over 1.5 to 2 lbs follow this procedure to re-calibrate the Pressuretrol:
Inside the Pressuretrol, right below the micro switch, there is a pivot arm. At the end of that arm you will see a screw pin that is activated by the diaphragm at the bottom of the Pressuretrol. If you look very carefully at that screw pin, you will see it actually has a tiny (I mean tiny) hex head on it. It takes a .050 hex wrench and you can turn it clockwise (Towards the bottom of the Pressuretrol to decrease the Cut-out pressure or counter clockwise to increase the cut-out pressure (which none of us want to do but who knows, your Pressuretrol may be really screwed up!). Turn the power to the unit off first. You may find the first attempt to turn that screw a little bit stubborn (relatively speaking) because it has some Locktite on it but it does turn. Don't turn too much, a tiny fraction of a turn goes a long way towards getting it adjusted where you want it (maybe 1/32 inch turn to start with) . You may need to play with it to get it exactly where you want cut out to be.
If you can't turn the hex screw because of the Lock-Tite, use a small soldering iron to melt the Lock-Tite.

mdeebs

@Fred thats funny, I was literally just reading your post that you copied here on the original thread. I will look into that. Also doing some reading on other threads here, would it be worth it to think about changing out the pressuretrol to a vaporstat? I already have intentions to install a tee with a low psi pressure gauge onto the pigtail, so I can change out the pressuretrol then too if that is a good idea.

Jamie Hall

Vapourstats are much more accurate and repeatable -- but they are also much more expensive. If you can get the pressuretrol calibrated (use that new low pressure gauge!), on a one pipe steam system you'd not gain much.

mdeebs

Thanks for your all your help @Fred and @Jamie Hall. Unfortunately I’ll be out of town for the rest of the week, so I’ll pick up the required parts and report back on Monday after I make the adjustments.

mdeebs

Here’s an update:

I installed the Gorton #2 valve at the end of the main run. The vent works like a charm. It’s nice and quiet, and it vented the main in what seemed like seconds. However, the hissing radiator is still venting loudly. I believe the pressure in the system is still too high.

I teed in a 0-5 psi gauge on the pigtail for the pressuretrol. The 0-30 and 0-5 aren’t in agreement, so I’m assuming the pigtail is clogged or the 0-30 is just inaccurate. The 0-5 reads 0.5 psi when the 0-30 reads 2 psi, 2 psi around 4 on the 0-30, and so on.

The boiler cut out after one heating cycle around 2psi on the 0-5 gauge. The next cycle, the boiler maxed out the 0-5 gauge and reached 7psi on the 0-30. I lowered the set point on the thermostat so that the boiler turned off before increasing anymore. Does anyone have any idea on what is causing this? Is it that the pigtail still needs cleaning, or calibrating? Or is something else amiss?

neilc

did you ever clear that pigtail so that when you blew into it,
it didn't / doesn't spit back at you?
you mentioned this early in the thread, and this tells you the pigtail isn't clear all the way back to the boiler.
post a picture of the pigtail and where it connects to the boiler.

mdeebs

The pigtail did spit air back at me when I blew through it the first time. I have tried sticking a flexible wire and a zip tie down the pigtail. Maybe I just haven’t done a good job cleaning it. I attached a picture of the pigtail set up.

Edit: this picture was taken after I lowered the heat set point so the pressure is dropping as the picture was taken.

neilc

easy enough test to just pull the new gage and blow in there again,
It should offer little to no resistance(like breathing thru a straw) once you clear the water in the bottom of the pigtail loop.
if you can't breath back to the boiler, then the Ptrol can't either, and can't see actual pressure.
The steel pigtails are more prone clogging.
get yourself a brass replacement.
prime the pigtail with a splash of water before you put the gage back on.
I think you're caked right at the boiler,
did you try turning that pigtail out ?

mdeebs

I tried unscrewing the pigtail from the boiler but the threads wouldn’t break loose and I was hesitant to push it too hard and break or bend the pigtail.

Pardon me if I’m mistaken but if that 0-5 gauge can see pressure then shouldn’t the pressuretrol be able to see it too? Unless the pressuretrol isn’t working properly, the pressuretrol should be cutting in and out at 0.5 and 1.5 psi according to that 0-5 gauge. Whether the 0-5 gauge is reading the correct pressure is independent of this

Fred

I can't see the metal indicator tab on the Cut-In scale on the front of your Pressuretrol. I assume it is set on the .5 on the scale. Did you take the cover off of the Pressuretrol and set the Differential wheel (white wheel) to "1"?
If so, you may need to recalibrate the Pressuretrol. Also, you should be able to blow into that pigtail with no problem. Make sure the tiny orifice inside where the Pressuretrol mounts onto the pigtail is not clogged. If it looks like it has dirt/crud in it, ise a needle to clean it out. The diaphragm on the Pressuretrol is metal so you don't need to worry about poking a hole in the diaphragm.

neilc

mdeebs said:

I tried unscrewing the pigtail from the boiler but the threads wouldn’t break loose and I was hesitant to push it too hard and break or bend the pigtail.



Pardon me if I’m mistaken but if that 0-5 gauge can see pressure then shouldn’t the pressuretrol be able to see it too? Unless the pressuretrol isn’t working properly, the pressuretrol should be cutting in and out at 0.5 and 1.5 psi according to that 0-5 gauge. Whether the 0-5 gauge is reading the correct pressure is independent of this

probably a good call on taking it easy with removing the pigtail,
especially if you don't have a replacement, and mindset / skillset / time to deal with IF it broke.
about the 0 - 5 seeing pressure,
as you note, it is only seeing 10% of the 0 - 30,
and I'm one that will have more faith than others here in what the 0-30s can show us,
so yeah, the Ptrol is seeing what the 0-5 is seeing,
but are they both really seeing what is in the boiler?
pop off the 0-5 and see if you can breathe, (exhale only) back to boiler as easy as thru a straw.

I haven't tried the following myself yet,
kinda dreaming as I'm typing,

mini rooter (pending, patent pending),
go to the lawnmower shop / hardware store,
ask for an old(or new) short length of throttle cable sheathing,
2 feet should do, but if you take a full length, then you can have several different lengths, and can avoid having whipping cable, we probably don't want more than 6 inches unsupported cable outside the pigtail,
safety glasses for everyone,
one end in cordless drill, or plug it in, make sure the chuck is tight,
other end in open end of pigtail,
root away , , ,
it might whip around a bit, so be easy,
and ask helper to 2 hand it loosely(wear work gloves),
if, and this is IF, it makes it past the bend where the pipe diameter may oval more than would permit my rooter to pass,

might work,
might not,
gonna have to try

neilc

and I'm meaning the thin coiled metal throttle cable sheath,
NOT the plastic,
but who knows, either or both might work.

mdeebs

Fred said:

I can't see the metal indicator tab on the Cut-In scale on the front of your Pressuretrol. I assume it is set on the .5 on the scale. Did you take the cover off of the Pressuretrol and set the Differential wheel (white wheel) to "1"?
If so, you may need to recalibrate the Pressuretrol. Also, you should be able to blow into that pigtail with no problem. Make sure the tiny orifice inside where the Pressuretrol mounts onto the pigtail is not clogged. If it looks like it has dirt/crud in it, ise a needle to clean it out. The diaphragm on the Pressuretrol is metal so you don't need to worry about poking a hole in the diaphragm.

Yes, the Pressuretrol is lowered to 0.5 psi cut-in with a 1 psi differential on the white knob inside. I am assuming that I will need to recalibrate the pressuretrol. Hopefully that will solve the issues. I also bought new Gorton air vents for the six radiators in the house following Gorton's selection information on their website. Currently there is a mixture of big-box store vents and a couple of the thermostatic air vent valves similar to this one, but a different manufacturer:

https://www.supplyhouse.com/Danfoss-013G8250-Thermostatic-Radiator-Valve-Operator-Valve-Mounted-Dial-Sensor?gclid=CjwKCAiA1L_xBRA2EiwAgcLKAyjABb-TJKKYTCVqjo1cqDNvpgN9pv3ZNq8KatZ0fxKW06R_PTudaBoCIckQAvD_BwE

I will replace all of the air vents with the Gorton's tomorrow evening when they arrive.

mdeebs

Another update: I took the pressuretrol off again to try and make a better attempt at cleaning out the pigtail. I bought a pack of 14” cable ties and shoved a few down the through the pigtail. After some effort, I believe I got the pigtail clear. I recalibrated the pressuretrol to match the 0-5psi gauge reading according to the instructions provide by @Fred and.... it worked!

The boiler is now cutting out at 1.5psi reading on the 0-5 gauge, and starting the draft damper operation at around 0.7psi. The two gauges still aren’t in total agreement, but it’s much better than before. 1.5psi on the 0-5 reads about 3psi on the 0-30. After watching the boiler operate correctly through a few heating cycles, I felt confident enough to switch out the 0-5 gauge to a 0-3 gauge that I had purchased.

One other thing I noticed which I have a hunch was also playing a role was that whoever previously installed or worked on the pressuretrol left loose wire nuts sitting in the body of the pressuretrol. I kind of have a feeling one of the wire nuts was sitting beneath the lever arm of the pressuretrol providing extra resistance to its operation and delaying its cut-out. I’d like to smack whoever did that.

Last bit I can do is change out all of the existing radiator vents for the correct Gorton vents when they are delivered tomorrow. Hopefully that’ll be the last step to quieting everything down.

Fred

@mdeebs , so glad you got the pigtail open and the Pressuretrol re-calibrated! Don't worry about the 0-30 PSI gauge. They are never consistently accurate and as it relates to residential systems, only on the boilers because of some outdated insurance and local/state codes.

mdeebs

Last (and hopefully final) update: I replaced the air vents on my six radiators. Only one of them had a vent that wasn't a cheap knock-off brand. Two of the radiators had Danfoss TRVs, which I know aren't the worst things in the world to have. I wanted to see how the system operated with just air vents. I removed all the vents and TRVs and installed 3 Gorton #5s, 2 Gorton #6s, and one Gorton #C.

This made an ENORMOUS difference. The loud hissing radiator finally quieted down to a reasonable venting sound and almost silent when letting air back into the radiator. All of the rooms are now heating as evenly as I believe to be possible. The boiler didn't cut-out from pressure until all the radiators were full with steam.

Most importantly of all, the fiancee isn't complaining about the loud radiator. A big thank you to everyone that helped in this thread and the wealth of information that is available on The Wall. $300, some elbow grease, and the knowledge of everyone here fixed everything.