Pigtail Clogged?

Ransomed_Chicago

I'm still learning about steam systems (I have one in my house), so hope this is not a dumb question. I have a six-year old system with both a Vaporstat and a Pressuretrol on it. the Vaporstat ceased working last year, and the repair guy "wired around" it, saying that having both the Vaporstat and Pressuretrol is redundant. That said, this heating season, I'm noticing that the pressure gauge that comes off the Pressuretrol and pig tail sometimes "pegs" all the way to the max when I have run the system for a long time (for example, in zero degree weather. But also noticing it sometimes when I am just heating up the boiler for 15 minutes or so to do a weekly flush. In those instances, the sludge valve has a LOT of steam built up---haven't noticed that before. Is it likely that the pig tail is clogged? Is it as simple as removing the fitting above it and running a small brush (or wire through it)? And is the sealant on the fitting anything special? Or can I just use regular teflon tape when I put things back together?

JUGHNE

That repair guy doesn't understand your boiler very well.
Yes the pressure control is redundant to the vapor stat, however the P-control is most likely set as a high limit safety control.
Your pressure should be controlled by the vapor stat.
You are lucky that whoever installed your boiler realized the importance of adding the vaporstat as they are probably not standard equipment.

What does the gauge peg out at?

If you post pictures of the controls and gauge area someone here will give you more advice.

The original installer may be your best bet for future repairs.

Jamie Hall

Good grief. @Steamhead has a saying for this, but it's an understatement.

Why did the vapourstat quit working? And he wired around it??? OK. Step 1. Clean out the vapourstat's pigtail -- that may be why it quit -- and wire it back into the system, in series with the pressuretrol. If it still isn't working, find out why and fix it. Step 2. Clean out the pressurestat's pigtail and reinstall it (ordinary teflon plumber's tape is fine for these connections) and make sure it's working.
Step 3. Take a deep breath and be happy that nothing worse has happened. Step 4. Take a look at the pressure gauge. It should never even get close to "pegging out" -- though it might show a pound or so when the vapourstat shuts things down.

Step 5. Find a good steam man (your original installer, perhaps, or you could check on here under Find a Contractor) and make sure that the idiot who wired around the vapourstat never, ever gets back into your house.

Ransomed_Chicago

Thanks, guys.

Here are four photos. The gauge pegs out (meaning it could not go any further---all the way around and down to the bottom) if the system runs for long periods of time.

ChrisJ

Your epair guy disconnected your Vaporstat.

If the pigtail was clogged the pressure gauge wouldn't work either.


You should be using both, it is redundant, and that's the point. The fact he disconnected the Vaporstat makes him a knucklehead in my opinion.

Ransomed_Chicago

Thanks... Would it be worth me reconnecting the Vaporstat to see what happens? I honestly don't now recall the problem that resulted in him "fixing it" by wiring around it. I'm not sure I remember which connectors the two wires were on to be sure it is wired in series. Can someone provide info on that? Thoughts?

ChrisJ

You may want to consult the data sheet for the Vaporstat, but I believe you want them hooked to these two screws. Won't matter which one goes where as it's just a mechanical switch.

Please be sure to shut the power off to the boiler before connecting the wires.

Jamie Hall

Do reconnect the vapourstat. And I think @ChrisJ is right on the connections, but if you have a multimeter you can easily check. The connection pair you want is the normally closed pair.

The pressures are set right on the vapourstat, or at least at a good place to start from.

If things don't work with the vapourstat connected, find out why -- don't just bypass it again.

Fred

The correct connections are the Top screw and the Bottom screw. The center screw is left vacant of any wires.

Jamie Hall

@Fred -- right you are. That's what I get for not reading the data sheet. Sorry...

ChrisJ

Fred said:

The correct connections are the Top screw and the Bottom screw. The center screw is left vacant of any wires.

I think Fred is correct.
It had to happen sooner or later given enough years.

I updated the picture above.

LionA29

That's quite correct @ChrisJ.
The service guy should've informed him of the problem and noted by HO!

JUGHNE

You have another gauge facing the other direction mounted directly into the boiler. It is probably the original 0-30Psi which on your system should never even register movement.

The fact of having a vaporstat, brass piping for it and a 0-16 OZ Wika gauge indicate you having a vapor steam system, something envied by many who visit here. And you were lucky to have an installer that 6 years ago or more understood your system. It is obvious the last person did not.

True, the vaporstat could have failed to close to start the burner.
But repair guy should have realized the importance of not running the pressure above 12 oz of pressure and replaced it.
After cleaning the pigtail and piping of course.

Ransomed_Chicago

Guys, thanks for all the good info. JUGHNE's comments causes me to vaguely recall that the furnace would not start one morning a couple of winters back, and the service guy said that problem was the Vaporstat (and thus wired around it). I'll reconnect it in the morning and see what happens. I assume if the furnace does not start, then it is a bad Vaporstat. Will let you know what happens. If it's a bad Vaporstat, then I'm gonna be asking you guys how difficult they are to replace; looks like it would be simple as long as I know exactly which model to purchase (and where). I assume the settings would be the same as the one in the photo.

j a_2

Hi step back and snap a picture of the boiler and near boiler piping....Let's see just how good the installer did

Fred

I doubt it needs to be replaced but if so, The model number you want is the same as is on that label, on the inside, side wall of the unit, near the wiring, L408J1009 and is available from Supplyhouse.com:
http://www.supplyhouse.com/sh/control/search/~SEARCH_STRING=Vaporstat
I more suspect the pipe it is mounted on may be clogged. Even though the gauge may be reading pressure, there could still be a clog in the small section of pipe above the Tee that the gauge is mounted on. Being straight up, crud can get pushed up that pipe and still leave the right section of that Tee open.
In any case, it is easy to take off and/or replace. Just use a wrench on the hex fitting under the Vaporstat and/or the pressuretrol to remove them to clean the pipe.

Ransomed_Chicago

Here are three pictures of the install. The original installer (by the way) was not the same guy who wired around the Vaporstat.

Ransomed_Chicago

Thanks again for all the good info...keep you posted.

JUGHNE

As Fred said the vaporstat inlet could be fouled. But if so could give you intermittent operation. 12 ounces would keep it off, that pressure could be "captured" in the control and prevent it from starting again.
It would be good to clean all piping that is connected to both controls and the gauge. There is a small pinhole going into both controls that could plug. No sharps into those holes though.
Prime the pigtail with water before reinstall of devices.
Especially check the opening into the boiler for sludge.
All of this may not have been cleaned since the boiler was installed.

How about pictures of main vents in the basement on the return pipes. A couple of radiators and valves from each end is always interesting also.

MilanD

For what it's worth: on the existing vaporstat (vstat) check also that the differential scale, the one on the left, is not stuck. I once had this exact unit not cut in when the pressure dropped. Had to knock on it to get it to engage. This lead me to move that set screw a few turns back and fourth. This fixed it and I had no issues since.

Whatever you do, first do check the pigtail, and while at it, as the vstat will be off, also that the membrane on the vaporstat itself is not blocked too. Look at it and clean if needed. Gently. Little brush at first, and then blow some air at it, like with that electronics compressed air duster can, or very carefully with an actual air compressor as not to accidentally damage the pressure membrane inside the vstat, but get out any gunk in there. If this doesn't fix it, maybe a new vstat will. It's super easy to wire in.

MilanD

Come to think of this a bit: your cut in is at 4 oz (12-8). With a clogged pigtail or even vstat, it's quite possible some pressure would stay in there and prevent the vstat to make on the pressure drop.

KC_Jones

The company that bypassed the vaporstat, is it the same company that installed the boiler? Just looking at the piping I would suggest you use the original installer as they appear to actually know what they are doing. The person who bypassed the vapostat....not so much.

Ransomed_Chicago

How do I clean/clear the pigtail? Just use a flexible wire? Do I have to take it totally off? I assume priming would just mean be sure it is filled with water then it is replaced.

Fred

It's kind of hard to get a wire around that loop and actually get it clean. If you can take it off and clean it, that is best but if you just take the vaporstat/Pressuretrol off and blow into the pipe, you will know right away if it is clear or if it is clogged enough that you need to take it off and really clean it out. It's really simple, not intimidating at all. Make sure you look into the underside of the control(s) as well to make sure the little orifice is not blocked. When you put it back on, use a little teflon tape on the threads but don't let the tape spill over into the pipe opening. Yes, Priming means add a little water into the pipe. When you hear it run into the boiler, your good.

Jamie Hall

Several thoughts. The fellow who did the original piping knew what he was doing -- congratulations to him! If you can get hold of him, make sure he's aware of the Wall. We could use him!

And the comment on the possibly stuck vapourstat. They do, usually if the pipe is gummed up (I've had mine do that). Cleaning the pigtail (and yes, a flexible wire is the easiest way to go -- and then to prime you pour water into it. It shouldn't back up at all!) is easy enough, but as has been said, clean all the other pipes there out too.

JUGHNE

For pigtails sometimes a long cable tie will make the loop. I like to flush hot water thru it as I run the tie at least part way thru from each end.
Your pigtail may be iron,(original to boiler). The brass ones stay cleaner and are easier to clean.

Koan

It is probably easier to replace the pigtail rather than clean it. I had two, one was partially clogged and I could not get it clean.

For $5.00 it may be worth it to replace rather than clean, this is the one I used:

supplyhouse.com/Jones-Stephens-G60-000-1-4-Straight-Pigtail

But I can see @Jamie Hall s point that brass might stay cleaner.

That looks like a "newer" vaporstat. I recall reading here on "The Wall" that they are more prone to failure than the older mercury bulb type that I have.

I would remove all the gauge and vaporstat plumbing and see if it is hard to blow air through it while having an extra pigtail on hand.

Like @Jamie Hall said, when reassembling, don't forget to fill the pigtail with water before sealing up the plumbing to keep steam from frying the gauge and vaporstat.

Ransomed_Chicago

All, thanks for all the great information. It's 12 degrees here today, so I'm gonna be smart and not start this little project on a day when it would be nearly impossible to get a repair person out here if I have to be bailed out. But I PROMISE I'm gonna follow through and tackle this job once we get thru this current cold snap. And I'll follow-up with you guys to let you know the outcome, etc. You've been very generous with your info, to say nothing of your time! Much appreciated...

Ransomed_Chicago

Hey, guys. The temps in Chicago finally got above 20 degrees (actually 45 today!), so I tackled the above project mid-day. So here's the update: the short story is that I wired the V-stat back into series with the Pressuretrol. And the system seems to be working fine with the v-stat back on line. Everything started up just fine, etc. (But I do have a concern below....)

But before noting the concern, let me recap what I did: Before restarting the system, I cut power to the boiler and meticulously went through all the steps you guys suggested---cleaned the pipes (nothing was obviously clogged, but there was some gunk--as expected). Blew through the pigtail, which didn't seem clogged, but who knows what I might have blown into the boiler. I did run an extra long zip tie through the existing pigtail (great idea) and poured very hot water through it; the pigtail seems to be clear as water readily ran into the boiler chamber. I primed the pigtail before re-assembling everything. I also checked the orifices and membranes on the v-stat and Pressuretrol--no evidence of any fouling. Also moved the left-hand screw discussed above on the v-stat (but didn't change the settings).

So, things started up just fine; sure felt relieved! I then set the thermostat up to 72 degrees. I ran the boiler for about 50 minutes. During that time, it would run for approx 15 minutes, followed by a couple of minutes off. Followed by another 15 minutes or so of running, then off for two minutes or so, etc. It went through about three such cycles. I THINK (not 100% certain) that this pattern is different than before I put the v-stat back online today. Before today, the system seemed to have cut on/off more frequently before today--nearly certain of it.

Today, when I started the boiler, the pressure gauge was at about 350 (not sure which scale to use; see photo). During the first couple of 15 minute cycles, the pressure went up to a little above 400 and pretty much stayed put. During the third 15 minute cycle, I noticed the pressure started increasing above 400 and it finally "pegged" at just about the end of the third cycle. Keep in mind that the boiler had run about 45 minutes (more or less non-stop) by this point.

As soon as the third cycle finished (and the couple of minutes down time occurred), I took the thermostat back down to 68, so things shut down as expected. The pressure went back down to about 400 or so. I am posting one photo showing the gauge pegged, along with the Pressuretrol and v-stat so you can see the settings (which I did not change during the above process).

SO: Does the above description of events suggest any problem? I am particularly concerned that the pressure gauge pegged. Otherwise, things seem perfectly fine.

THANKS SO MUCH again for all the good advice!

Jamie Hall

Nice gauge. Presuming it is accurate -- which it probably is -- the vapourstat should shut off the burner at around the 520 mark. If you get the chance, observe it some more.

Fred

@Ransomed_Chicago , That 400 looks to be about 9 ounces of pressure (the outside scale on that gauge. That is fine. Pegging is high because we don't know what the pressure was beyond 15 ounces. However, the boiler typically won't run for 45 minutes unless you use set-backs. In any case, it seems like the Vaporstat is working. Regarding the 15 minutes on and off, Do you have a Cyclegard Low water cut-off on that boiler that may be cycling the burner on and off at intervals? What other controls are on the boiler. If the boiler shut down on anything other than pressure, that should be understood too.
Edited to change Pressuretrol to Vaporstat.

ChrisJ

Fred said:

@Ransomed_Chicago , That 400 looks to be about 9 ounces of pressure (the outside scale on that gauge. That is fine. Pegging is high because we don't know what the pressure was beyond 15 ounces. However, the boiler typically won't run for 45 minutes unless you use set-backs. In any case, it seems like the pressuretrol is working. Regarding the 15 minutes on and off, Do you have a Cyclegard Low water cut-off on that boiler that may be cycling the burner on and off at intervals? What other controls are on the boiler. If the boiler shut down on anything other than pressure, that should be understood too.

@Fred
If the Vaporstar was working, the gauge wouldn't have pegged.


Either the Vaporstat isn't working, or it needs to be dialed down some. I would turn the "MAIN" scale down to 8 ounces or so, and see what happens. If the system still pegs the gauge, turn it down to 4 ounces, if it still keeps pegging the gauge something is wrong.

Another option, and the one I generally do is wait until the boiler is running, and is near the pressure you want to shut down at and then start lowering the MAIN scale until it shuts off.


If that 15 ounce gauge has been over-pressured like this a lot, I doubt it's accurate anymore. I believe that's a bourdon tube type gauge and they don't like that, it can permanently damage them. An easy way to find out, is remove the gauge from the boiler and see if it zeros. If it doesn't, try to zero it with the screw under the plastic lens, the plastic lens pops off by prying it off at the edge. If it can be zeroed, it's likely ok.

BobC

I believe that is a 15oz gauge, the vaporstat is set for 12 oz with a 8oz differential. If the boiler is shutting down that indicates the vaporstat works but he calibration of that vaporstat might be off.

Try adjusting the right hand scale to 8oz and the left hand scale to 4oz and see what the gauge reads when the boiler is making steam.

Does the boiler have a Cyclegard low water control on it?

Bob

Fred

@ChrisJ It is possible the Vaporstat is off a few ounces. Honeywell puts those slots on the scales so they can be slide a bit to line the scale up with actual pressure. I guess I would temporarily take the Pressuretrol offline and see if the Vaporstat shuts the boiler down.
Also, without seeing the wiring, it remains a question as to if the PTrol and Vstst are actually wired in series or if they are wired together, causing either device to complete the circuit.
@Ransomed_Chicago can you verify that you are sure these devices are wired in series? Each terminal on each device should only have one wire on it.
Also, my error above. I meant to say the Vaporstat seems to be working.

billtwocase

Not to switch gears here, but I would recommend replacing the drop for the relief valve with brass or copper. Black iron is a no no on the discharge side

ChrisJ

billtwocase said:

Not to switch gears here, but I would recommend replacing the drop for the relief valve with brass or copper. Black iron is a no no on the discharge side

Some places seem to allow it.
In my area, the inspector would fail it. He wants to see copper or brass with a union. I agree with the union, especially if it's threaded pipe otherwise it's a pain to change or inspect.

billtwocase

I have found them plugged with rust, and over 40 PSI on the boiler. There is a reason why non ferrous is a requirement

JUGHNE

Could you post a picture with the cover of the other pressure control removed. Your "fix-it" guy may have messed with the wires inside there also.

Ransomed_Chicago

Thanks all...will post a picture of the pressure control w/cover removed and answer some of your questions sometime after 7 pm CST tonight. Thanks...

Ransomed_Chicago

OK...to answer one impt question that was posed: Yes, there is a Cyclegard Low Water Cut-off installed. Regarding the gauge: When I read the gauge-related comments, a light bulb came on: I took pictures of the gauge, controls, etc. just after I reassembled everything, and the gauge CLEARLY was not at zero. In fact, it was somewhere up around 340 or so. Since I don't mess with these things, the thought never occurred to me that it should be at zero when it if removed from the unit----it was not. So I assume this points pretty clearly to needing to buy/install a new gauge. Can someone please point me to a web source? And, if possible, if a specific gauge to order? Again, I was a teacher, not a boiler guy!

As for the picture of the wiring: I am attaching to pix (two diff angles) of the PressureTrol unit. The BLACK wire coming into the box goes from the boiler (body) to the PressureTrol. The BROWN wire is running from the PressureTrol over to the v-stat. I'm not an electrician either: do these seem in series rather than parallel?

I'm going to wait to hear back from you guys before I mess with any settings on the v-stat or PressureTrol, especially since the gauge is likely needing to be replaced.

THANKS!

Jamie Hall

Wiring looks OK. There is quite a variety of 0 to 3 psi gauges; I use a Kodiak from Amazon, and others use other makes.