Pigtail and/or pressuretol keep getting clogged on my Burnham steam boiler

Wes2

Hi. I have a Burnham, natural-gas steam boiler in my home. Once or sometimes twice a year -- usually when it is VERY cold outside and my boiler therefore has to run quite a lot -- the boiler's pigtail or its pressuretrol gets clogged. I know this because every time it happens, I call out a repair person and he cleans out either the pigtail or the pressuretrol or both and that resolves the problem. Does anyone know why these things would get clogged once or twice a year? I keep the boiler's water clean by flushing it and replacing the water every few weeks, so I presume it's not a water-quality problem. I'd be grateful for any advice.

delta T

"I keep the boiler's water clean by flushing it and replacing the water every few weeks"

By this do you mean, you drain the entire boiler and refill it with fresh water?

If so, that is your problem. You want to change the water as little as possible. Any time you add fresh water, you also add oxygen. The oxygen will corrode any ferrous parts of your system (pretty much all of it in your case). I suspect this is what is leading to the pigtail getting clogged.

if you have a float style low water cut off, that should be blown down every two weeks, but that is not releasing enough water to make a difference. Draining the entire boiler however.....that is a different matter entirely.

STEAM DOCTOR

Make sure you have a brass pigtail

KC_Jones

Wes2 said:

Hi. I have a natural-gas-powered Burnham steam boiler in the basement of my house. Once or sometimes twice a year -- usually when it's VERY cold outside and the boiler as a result has to run quite a lot -- either the pigtail or the pressuretrol to which the pigtail is connected gets clogged and the boiler stops working. I know this because every time the boiler stops working, I call out a repair person and he reports that after cleaning out the pigtail and/or pressuretrol the problem goes away. I drain and replace the water in the boiler every couple of weeks, so I don't think it's an issue of dirty water.

Does anyone have any hypotheses as to why the pigtail and/or pressuretrol would be getting clogged once or twice a year? It seems to me odd that this would happen as much as it does.

Do not do this, I repeat do not do this. Fresh water is bad news and you should limit it as much as possible.

I agree with @STEAM DOCTOR what material is the pigtail? If it's steal and you keep replacing all the water like that, you are the most likely cause of the problem.

Also pictures of your set up would be a good idea, on occasion pigtails are installed in an unfavorable location.

Pics of the boiler, piping and the pigtail, not too close so we can get context.

Jamie Hall

Totally agree with @KC_Jones -- Do NOT drain and replace the water. You're killing your boiler. It may be necessary, as part of the yearly maintenance, to blow a few gallons of gunk out of the bottom drains. If you have a float type LWCO, that needs to be blown down perhaps once a week (a quart or two, maybe). Otherwise, no need to either drain or refill (Cedric has never been drained...).

EBEBRATT-Ed

Let see some pictures of the pigtail/pressure control set up.

Unless their is something very unusual going on

I would be very surprised to have a pigtail or a control plug in that space of time

Wes2

Thanks, everyone, for the comments and thoughts.

It's hard to tell what material the pigtail is without looking at it in daylight but it appears probably to be either copper or bronze, to my untrained eye.

I understand from your comments that I should STOP draining and refilling the water so often. However, I have to put more water in on average every 10 days to two weeks because the water level gets so low in the system, so maybe that is part of the problem. Is that normal, to need to put more water in so often? There are no obvious places that water or steam is leaking.

Pictures attached.

neilc

From here that pigtail looks steel, even slightly rusted there.
Scratch it with a knife edge, if it shines silver it's steel, or try a magnet.
If it shines yellow or orangy, it's copper or brass.
AND,
That pressuretrol looks to be set too high.
the scale on the right, the main, looks to be up around 8psi,
dial it down to just under 2psi,
the scale on the left, differential, set it at 1psi.
These are the screws up on the top there.
It might be the high pressure is pushing junk around too much and landing in the pigtail.
And like everyone else said, stop doing the drains.

Jamie Hall

As @neilc said -- pressure is way too high. That may be part of why you are using too much water (you are) as most vents will not function properly over about 3 psi -- and are probably damaged at best.

But the amount of water you are adding is more than you should be, although not ridiculous. Does the boiler ever shut off on pressure? If it does, you may not have a really serious leak..

Fred

When they tell you the pigtail and/or Pressuretrol is clogged, I don't know how they'd know that. That Pressuretrol is too close to the front of the boiler to turn it off and the entire it can't swing from right to left to take it off without removing the other controls and the sight glass, pressure gauge and Low water cut-off. Looking at where the pigtail connects to the boiler and to the Pressuretrol, It doesn't look like they have been disturbed or had new tape put on them in years.

EBEBRATT-Ed

@Fred,
I thought the same thing about the pressuretrol swing but it looks like it will spin??

But, as you mentioned that thing doesn't look like it has ever been disturbed

Looks more like steel than brass to me but a magnet will tell.

neilc

I'm now seeing what you're (yous) are saying about swinging the Ptrol,
it's close,
How did it get on there to begin with?
and that mc looks shiny right at the box where someone would have to grab or push on it,
life's mysteries , , ,

Wes2

OK, I put a magnet up to the pigtail and the magnet stuck to the pigtail. So I presume that means the pigtail is NOT copper or bronze. I guess it must be steel and/or iron if a magnet stuck to it. Do you definitely recommend replacing it with a bronze or copper one?

I'll definitely stop draining and putting in water.

I'll also change the pressuretrol to the right settings. (The last repair person who came I saw adjusting the pressures, and I have no idea why he set them to those levels.) Maybe that will cause the system to need less water added and that in turn will cause less trouble with the pigtail and/or pressuretrol clogging so often.

ethicalpaul

STEAM DOCTOR said:

Make sure you have a brass pigtail

^^^

Wes2

Hi again. An update: I dialed down the pressuretrol considerably as advised: I set the pressure on the right (i.e., the main) to 2 and the pressure on the left (i.e., the differential) to 1. That caused the boiler never to turn on. So I bumped the pressure back up to the original levels (main 8, diff 2) and now the boiler is working again. Any thoughts as to what might be going on here?

Dan_NJ

It sounds like the pressuretrol is not properly calibrated. When you change out the pigtail you can add a low pressure gauge to get a better idea what's really happening. The differential setting on my 404a pressuretrol is off by 50% at its lowest setting of 1. I only know this because I added a 0-3 psi gauge on the pigtail.

Wes2

Well, there's a pressure gauge on the side of the boiler that and it shows that the boiler pressure is getting up to around 10 psi at which point the boiler cuts off.

Dan_NJ

10 psi is definitely higher than you want. The calibration on my original pa404a was screwed up such that if I set it to .5 cut in it would never cut in at all. Sounds like something similar could be happening with yours, the micro switch is not closing at the cut in pressure.

Fred

Dan_NJ said:

10 psi is definitely higher than you want. The calibration on my original pa404a was screwed up such that if I set it to .5 cut in it would never cut in at all. Sounds like something similar could be happening with yours, the micro switch is not closing at the cut in pressure.

There were a couple years on here where some DIY'ers thought stretching the springs was the fix for calibration. If that Pressuretrol was on the boiler when you bought the house, you don't know what someone else might have done.

Dan_NJ

I built a little rig like Gordo's here to test my own pa404a and calibrate it. Mine is still inaccurate but close enough I guess:
https://youtu.be/mE1-QuUx4_c

Dan_NJ

I knew I had seen this one also - you might find this Gordo test more relevant to your model - you could be having something like this going on.
https://www.youtube.com/watch?v=3AnN99dfxgY

neilc

Wes2 said:

Hi again. An update: I dialed down the pressuretrol considerably as advised: I set the pressure on the right (i.e., the main) to 2 and the pressure on the left (i.e., the differential) to 1. That caused the boiler never to turn on. So I bumped the pressure back up to the original levels (main 8, diff 2) and now the boiler is working again. Any thoughts as to what might be going on here?

is there any chance you took that Ptrol off, and checked the pigtail?
If these other guys are right about it not being possible to swing the Ptrol, maybe the service techs you've been seeing have been tweaking those Ptrol settings up every time, and the pigtail is never been checked or cleaned.
You would want to cut the pigtail free, and replace with new, and add some extra nipples and or elbows to gain clearance for future cleanings.
a union or 2 could save some unwiring in the future also.

Gordo

@Wes2: Hi! Based on what has been said so far, and your pictures, I would say that steel pigtail is clogged. Replace it with a red brass one.

"Yes, but how?"

Well, I'd remove the screws underneath the diaphragm of the pressure controller, disconnect the wires and remove the gray box.

Take it to place that handles mercury safely.

Spin off the diaphragm. Then, remove the steel pigtail.

Put them in recycling.

Install a red brass pigtail that has one end longer than the other. Install a 1/4" brass male tee on top of your new pigtail. Install a PA404 pressuretrol on the male part of the brass tee. The tee allows the installation of a low pressure gauge and a place to blow into and test the pigtail. Or, plug the outlet of the tee with a 1/4 plug for now.

I may have skipped a few steps, but that should put you on the road to happy steaming.

https://www.youtube.com/watch?v=JgdHYQsa5hg

Jamie Hall

Well... except I wouldn't get rid of the mercury pressuretrol. The things are bullet proof, which the microswitch ones aren't.

However. I hadn't quite realized that it was mercury. Those are extremely sensitive to being level -- or not being level. There are two ways to level them. One, most of them have a small pendulum arrow on the back. That must be hanging straight down. The other is to take a good short level -- 6" -- and place it across the top of the box and level that.

If the pressuretrol is even slightly out of level, it can be a few pounds off. Significantly out of level and anything's possible. Your description of when you turned it down and it wouldn't run sounds to me as though it's badly out of level.

Gordo

@Jamie Hall: I've tested quite a few of those Hg controls and that model is just simply not very good. Between that Hg model and the PA404a, the PA404a is FAR more precise. And you can adjust the PA404a for better accuracy. I have yet to figure a way to adjust that particular Hg control to get it to work below 2 psi. I've pulled a dozen or so of those controls and sent them to the Hg recyclers.

On top of that, the PA404a is not nearly as fiddly as a Hg unit vis-a-vis leveling, as you have quite properly pointed out

Having said that, I would heartily agree with you that the Hg vaporstats are another matter, as they seem to have been better made than the new micro-switch units.

https://www.youtube.com/watch?v=JgdHYQsa5hg

Gordo

https://www.youtube.com/watch?v=3w6-Ypn9_bs

EBEBRATT-Ed

Or hacksaw the pigtail and take it out in two pieces

Gordo

@EBEBRATT-Ed

ethicalpaul

And if putting down all the way to the right setting doesn’t work, at least try something more reasonable than 8, like 3

Also I agree with @Fred and @neilc that it’s a mystery how the tech has been removing it to allegedly clean it. I doubt they have been.

Is that a mercury one? It looks so new.

BobC

make sure the pigtail loop is not visible when looking at the face of the pstat or vstat, if you can see the full loop the movement is much worse. When leveling a mercury bulb pstat or vstat do it when the system is making steam because the pigtails move when they get hot.

I agree the mercury devices are much better than the microswitch equipped ones.

Bob

KC_Jones

Clogged pigtail, solution turn the pressure up higher. I doubt they have been cleaning it, but I bet they have been charging to.

As said if it’s not the pigtail, then the pressurtrol needs adjusted or replaced. All things the preofessional you hired should have known.

JUGHNE

I would saw it off, that will give you a good look inside.
Make sure the hole going into the boiler is clean.
Make sure the small inlet hole going into the control is clear, don't poke too hard.
Use a nipple and union then your new pigtail and retry the control you have.
You could put a tee under the control and branch a nipple and 90 over to install a new 0-3 PSI gauge.
Then leave the old gauge as is for comparison.

Could be a warm weekend project if you line up all the parts.
You could plug the new gauge hole until it arrives.

Lance

To set a pressure means you can accurately read a pressure. To set a pressure switch is to prove its settings to the pressures. Boiler new but are the returns? You started changing water to stop the once or twice season clog gauge problem? If so perhaps your returns need flushing or replacing. A return never flushed is a great place for sediment to eventually return to the water. One job I did was so bad, after 3 flushings; I had to replace the returns. Their insides looked like the Luray caverns.
A boiler is just a pot that boils water, the rest of all the pipes and controls is the heat system. All the preceding comments are good advice. Beware of using anything not rated for at least 15 PSI on this boiler.

Wes2

I'm going to leave an update as to the resolution of this issue, in case anyone comes across this post in the future. I found a different repair person and he identified the true problem: the pressuretrol wasn't working correctly, such that it would only operate if the pressure was set VERY high. He replaced it with a new pressuretrol and set the main pressure to a very reasonable 2 psi, and now everything seems fine. The steel pigtail didn't seem to be clogged but he replaced it anyway with a brass one.