1 pipe steam system help. Boiler runs for long time. Return pipe leaking water

abinsapkota

Thanks in advance for any help.

I live in an old house with steam system that is probably 20-30 years old. Everything has been working fine till now but running into some issues since I turned the heat on this season.

It is a 1 pipe steam system with 4 radiators on 1st floor and 4 in the 2nd floor. Here is the issue I am having

- The boiler keeps running for a long time until the thermostat turns off the heat.
- The pressure gauge in the boiler says 10psi (not sure how accurate this is)
- The main vents (I am assuming this, they are on the smaller angled pipe going back to the boiler) keep hissing and releasing steam (after the radiators are all hot, 20-30 mins)
- Once the hissing starts, i can see water dripping from one of the joints on the same smaller angled pipe going back to the bottom of the boiler. Not sure it is because of loose joint or overpressure?
- The pressuretrol is set to .5psi for cut-in and 1 psi for diff but it never actually turns the boiler off. It is a Honeywell PA404A 1009 2. When I lift the bottom plate of the pressuretrol manually the boiler does stop running.
- The pigtail is connected to the top of the water level glass and it never seems to get hot to the touch farther than halfway. Not sure how the pressuretrol works

Please advise. Is this a bad pressuretrol, bad pigtail? Is the water leak because of overpressure? I have already had several plumbing companies come in and they all changes one thing or another but the problem is still there.

- 1st plumber said it was a venting problem and replaced all vents on mains and radiators.
- 2nd plumber adjusted pressuretrol and replaced a section of pipe saying it was corroded (pipe that goes from water supply into the boiler for a separate issue.)

Jamie Hall

It's unlikely that the pressure gauge is accurate. Howver, one needs a 30 psi gauge for insurance.

It is also likely that the pigtail -- despite its location -- is plugged, although the pressuretrol might be bad, too. So... what you need to do is to take the pressuretrol and pigtail off, and make sure the pigtail is open. Then you need to make sure that the openings on the gauge glass into the boiler are also open. Quickest way to do that is to watch the glass as the boiler operates. The water level should change as it heats up, and should not be steady when its running (not wildly unsteady, but not steady, either). If there's any question, you can remove the glass -- but carefully, it's fragile -- with the boiler off and check the openings. If there are blowdown valves on the glass, you can try them, too.

Then... get a low pressure gauge (0 to 3 psi) and T it onto the pigtail with the pressuretrol and watch the pressure.

abinsapkota

Thanks Jamie

I turned the heat on and observed the following:

- water level on glass gauge goes down and moves up and down a bit when the boiler is on.
- i can also see steam on the top of the glass where there is no water
- the gauge area get hot to the touch. the end of the pigtail (copper I think) gets hot where it connects to the gauge up to about halfway up the curve. But the end of the pigtail where it connects to the pressuretrol stays warm at most.

Maybe there is a clog on the pigtail. How do I take the pigtail off? Pics below:

ImYoungxD

I suggest adding more water to 50%-60% of the glass. Yours is around 40%.

As for the pigtail. See video. It's easy. Make sure you turn off the power on the boiler before taking the pressuretrol off. Take photos of the wiring incase you forget which one goes where.
https://youtu.be/yfVdd9NDn3w?t=131

Once it's off, see if you can run tap water through it, if not, it's clogged.

Add some vinegar inside, wait 5-10 mins, use a pipe cleaner to dig inside.

Run tap water through again and make sure water goes through and out with no blockage.

If it's blocked, repeat the vinegar steps again.

KC_Jones

It appears by those pictures that you would have to remove the gauge glass and fittings to access the pigtail for cleaning. The glass looks like it's either new or at least newer than the fittings so it might not be too bad, but I wouldn't do it when the stores are closed just in case something breaks (murphy lives in my house so I am paranoid).

By your description of the operation it sounds like a blocked pigtail, but there is really only one way to find out and that's to remove it.

JUGHNE

Show a picture of the location of the pressure gauge, please.

abinsapkota

Thanks I will try that. The pic was taken when the boiler was operating. Thats why the water level is lower. It goes back to that water level line when it is off.

The current one there is copper. Is it OK to replace it with a steel one if I break it? My local plumbing store only carries these

https://www.murraysupply.com/Product/88346

KC_Jones

I would never do steel, they tend to crud up more frequently than brass (what you have now). Steel would be a downgrade, honestly kind of shocking they only stock steel, if they only stock one the brass would be better.

abinsapkota

More pics:

- The last guy who came is replaced the safety valve since it was tripping. He also changed the glass on the gauge (said it was cracked and leaking)
- The gauge never goes below 5psi even when the system is off. Thats why I was questioning the accuracy of the gauge. It climbs to 10psi (5psi net I guess) when the boiler is on.
- The boiler never shuts off until the thermostat gets to the set temp and calls the boiler to shut. Takes 30-45 mins. I am assuming the boiler constantly running for 45mins is probably not normal, right?

Its hard to find someone who know steam systems. Any recommendations for the Boston area?

JUGHNE

This is a modification for that boiler type.
The gauge was removed and this installed.
The tee and plug allow you to clean that port into the boiler.
The double piptail was installed because this is a vapor stat with mercury inside and very sensitive to vibration.
You would only need a single pigtail.
The gauge is 0-3 PSI.
You can add another 1/4 tee and reinstall the old gauge.
Use brass or stainless steel for all of the 1/4" fittings.

You may have to saw off the pigtail about 2" out of the sight glass connection, unscrew the stub and plug that opening with a 1/4" brass plug.
That is not designed well to unscrew anything.

Note: BTY, not my welded header....however it works well.
This is a vapor system running 8-12 ounces or so.

abinsapkota

There is no space to turn any of the pipes. Wonder how they put this thing on. I think this is way above my comfort zone :-)

ImYoungxD

That gauge is broken. You would need a 0-3 or 0-5 psi gauge which can be attached with the pigtail.
Something like this https://us.v-cdn.net/5021738/uploads/posts/5871/P1030002.JPG

My boiler runs 60-90 mins non-stop from cold start. Once it reaches 1.5 psi, it stops for 5 mins then turn on again for 15-20 mins until the thermostat is satisfied. Not sure if it's an issue.

As for the water leaking from the joint, it could be overpressure or the joint needs to be tighter. if you can, take it off and add plumbers tape.

nicholas bonham-carter

That location for the pigtail, makes for a complicated removal, so I would put it back after cleaning with some brass fittings to make it easier for the next time. Come out of the gauge glass fitting with a brass street 90, then a long brass nipple up to the top of the boiler, a brass Union, and then the pigtail which screws into the pressuretrol. Putting a tee at the top with some more elbows, and nipples would allow for the installation of a 0-3 psi gauge, to verify the operation of the pressuretrol.
The problem with those pressuretrols is the possibility of the adjusting screw, and it’s linkage becoming disconnected when you dial the pressure down, leaving you with no upper pressure limit stop. A vaporstat would be more accurate, and reliably adjustable.
At pressures in excess of 3 psi, the main vents may have become damaged, so have a look at those and post pictures here.—NBC

abinsapkota

I tried tightening the joint but that didn't work. The pipe is leaking from the joint pictured below. Its unusual for it to leak from the top, no?

JUGHNE

The lack of turning space is why I recommend the sawing off, leaving a stub long and straight as possible to get a tool on for unscrewing.

The gauge can be unscrewed by lifting the top panel of the jacket and applying a wrench. I believe the one I pictured had a brass 1/2 x 1/4" bushing for the gauge. If the larger bushing will not come out then you can just use the 1/4" port.

abinsapkota

nicholas bonham-carter said:

That location for the pigtail, makes for a complicated removal, so I would put it back after cleaning with some brass fittings to make it easier for the next time. Come out of the gauge glass fitting with a brass street 90, then a long brass nipple up to the top of the boiler, a brass Union, and then the pigtail which screws into the pressuretrol. Putting a tee at the top with some more elbows, and nipples would allow for the installation of a 0-3 psi gauge, to verify the operation of the pressuretrol.
The problem with those pressuretrols is the possibility of the adjusting screw, and it’s linkage becoming disconnected when you dial the pressure down, leaving you with no upper pressure limit stop. A vaporstat would be more accurate, and reliably adjustable.
At pressures in excess of 3 psi, the main vents may have become damaged, so have a look at those and post pictures here.—NBC

Not sure I have any main vents. The only vents in the basement are these on the angled pipe. They are Vent-rite #33. Replaced last winter by the same plumber who changes all the vents on radiatiors with Vent-rite #1s (first floor dials at 7 and second floor at 5)

abinsapkota

JUGHNE said:

The lack of turning space is why I recommend the sawing off, leaving a stub long and straight as possible to get a tool on for unscrewing.

The gauge can be unscrewed by lifting the top panel of the jacket and applying a wrench. I believe the one I pictured had a brass 1/2 x 1/4" bushing for the gauge. If the larger bushing will not come out then you can just use the 1/4" port.

How do you remove the existing 0-30 gauge? Looks like your vaporstat is coming off the port where the built in gauge currently is.

KC_Jones

Those are your main vents and unless yours mains are about 3' long they are woefully inadequate.

Need the length and diameter of the mains and we could recommend how much main venting you need.

Where are you located? We may be able to recommend a contractor that actually knows what they are doing.

JUGHNE

That union might be fixed by just taking it apart and cleaning the joining faces and the threads on the ring and union body.
If the faces are grooved then it should be replaced.
Not a real difficult job.

abinsapkota

KC_Jones said:

Those are your main vents and unless yours mains are about 3' long they are woefully inadequate.

Need the length and diameter of the mains and we could recommend how much main venting you need.

Where are you located? We may be able to recommend a contractor that actually knows what they are doing.

I live in Medford, MA. A recommendation for a contractor would be great. Thanks

KC_Jones

abinsapkota said:

I live in Medford, MA. A recommendation for a contractor would be great. Thanks

Easy, if he's available @New England SteamWorks

https://heatinghelp.com/find-a-contractor/detail/new-england-steamworks

@Charlie from wmass may be another option if he drives goes that far.
https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating

Both are fantastic with steam.

ImYoungxD

I would suggest insulating the dry line with 1 inch fiberglass insulation. Helps lessen the boiler time and saves you money.

abinsapkota

KC_Jones said:

Those are your main vents and unless yours mains are about 3' long they are woefully inadequate.

Need the length and diameter of the mains and we could recommend how much main venting you need.

Where are you located? We may be able to recommend a contractor that actually knows what they are doing.

Sorry in advance for my ignorance.

- I have one big pipe coming out of the top of the boiler. It is 2.5" in diameter. Goes up 2.5' vertically
- This pipe then goes 2.5' horizontally. There is a T that goes to a 2" pipe to the LR radiator (closest)
- The same main pipe turns 90 degrees and goes 9 feet before going to another section of pipe (like a U) and then branching to three remaining radiators on the 1st floor.
- The same main pipe keeps going another 7' which branches to several 2" pipes that go to the SF radiators.
- So total of 21 feet in total
- There is also a 2" pipe next to it that is sloped down that goes back to the bottom of the boiler (this is the pipe that has the vents and is also the one leaking at the joint)

KC_Jones

Just guessing here, but I'd say the current boiler location was not the original boiler location in that house.

I speculate you have/had 2 mains and they were tied together on the last boiler install and the boiler was moved.

This is all judging by what presents as newer versus older pipe. I would guess that first tee to go to the radiator used to be attached to the one main and it was all reconfigured.

The mains should be separate to allow for the system to be balanced. I marked in red what would be considered mains with your current configuration.

abinsapkota

KC_Jones said:

Just guessing here, but I'd say the current boiler location was not the original boiler location in that house.

I speculate you have/had 2 mains and they were tied together on the last boiler install and the boiler was moved.

This is all judging by what presents as newer versus older pipe. I would guess that first tee to go to the radiator used to be attached to the one main and it was all reconfigured.

The mains should be separate to allow for the system to be balanced. I marked in red what would be considered mains with your current configuration.

Got it. That pipe is about 24 feet in length (adding the section above the main pipe) from the boiler. Thanks.

So a Vent-rite 33 is probably not enough venting?

KC_Jones

abinsapkota said:

So a Vent-rite 33 is probably not enough venting?

I don't think that is enough venting for any steam system. You have 2 main vents in the one picture so you would have to figure out how much pipe each one is serving. Measure from the boiler to those vents, the initial run of a single pipe to the "split" would be divided between the 2.

It's tough to say without being there, if you get the pro in there, they will be able to figure it out better.

abinsapkota

Thanks all. I will contact the pros you recommended.

All this is way over my head. Don't want to risk creating a bigger problem that it already is.

abinsapkota

JUGHNE said:

That union might be fixed by just taking it apart and cleaning the joining faces and the threads on the ring and union body.
If the faces are grooved then it should be replaced.
Not a real difficult job.

Did what you said about the union. Looked inside the pipe (as much as I could) and no blockages.

Fired up the boiler. Started leaking after about 35 mins of boiler running. No change on the 0-30 gauge (most likely broken).

Both the return main vents opened up and started hissing continuously as well along with some of the radiator vents.

JUGHNE

If the 2 inside faces are clear then sometimes I have used an 18" and 24" pipe wrench for tightening. You can put cheater pipes on shorter wrenches for added leverage.

Maybe an easy temp fix for the pigtail:
Take a picture of the wiring connections, sharpie marks help if all the same color or white tape also.
Unscrew the control with a wrench on the bottom flats.
Insert another wrench or hammer handle thru the loop of the pigtail to keep from putting strain on where it connects into the sight glass.
Do not remove the 4 screws on the bottom.

See if you can blow thru it. Something like a large nylon cable tie might make it around the loop.
You could use a little compressed air if you shut off the top sight glass valve to keep the air out of it.
Check the inlet of the bottom of the control, you will see a small pin hole in it. There is a diaphragm under that hole.....you do not want to puncture it.

If it is clear then pour water into the loop, you will hear it trickle into the boiler water. You need to prime it with water anyway.
That water is why the bottom of the loop is hot and the top is cool...…..open the sight glass valve if off.

ImYoungxD

The union or piping thread could be damaged.
The main vent shouldn't be hissing. Those needs to be replaced with big mouths.

Since the pigtail is clogged, you could be running over 3 psi which causes the vents to hiss cause there is a lot of pressure.

Fred

The fact of the matter is your boiler pressure is probably running much higher than it should and that likely means the pigtail (looped pipe) that the Pressuretrol is mounted on is clogged or the Pressuretrol itself has failed. The leak at the fitting, on the return pipe is likely the result of running at higher than normal pressures. A pipe that leaks at 10 PSI may well not leak at 1 or 2 PSI. Fix the pressure problem and I suspect the leak will resolve itself.

abinsapkota

Thanks guys for all the advice. Really appreciate it.