Steam Radiator PSI too high?

datawaym8

We have a Burnham steam boiler that supports 4 units. Each unit has 3-4 radiators.
I believe the current PSI is set to 3. Sometimes, the pressure can go as high as 10 according to the pressure gauge. See pictures for the PSI setting and gauge. Is this normal?

I also want to point out that a couple of our radiators air vent have been making hissing noises and one spits water. The one that spits water we intend to replace the vent. I also can hear water boiling sound in a couple of the radiators during the first 20 min or so when radiator kicks on.

This is my first home with steam radiator and it's driving me insane.

neilc

yup, 10 is bad,
Ptrol is set too high,
and pigtail is likely plugged,

dial the indicator to the bottom, counterclockwise on that screw head on top above the scale, gently,
don't go past the point of resistance or inside linkage may disconnect,
if by chance the boiler does not start, and after checking the pigtail, you may have to raise the indicator just a turn or 2 so burner will restart reliably,

under the grey cover there is a white wheel, it should be set to 1,

the pigtail is the looped pipe under the Ptrol,
your's looks to be steel, not ideal as they tend to plug more easily,
you need to check it that it is clear, and that you can blow thru it, all the way back into the boiler, so the Ptrol can see the boiler pressure,

turn the boiler off, remove the wires from the Ptrol, (take a picture of where they are landed),
using the flats under the Ptrol, unscrew from the pigtail, blow thru the pigtail,
can you?
if not, you need to poke, prod, snake, and remove the junk from the pigtail,
you may remove the pigtail and go at it from both ends,
or replace it with brass(best),
still need to blow thru to boiler, sometimes the connecting port will clog also,
before reinstalling Ptrol, prime the pigtail with a little water, 1/4 cup will do ya,

datawaym8

neilc said:

yup, 10 is bad,

In the meantime, can i still use the radiator until i fix it?

neilc said:

Ptrol is set too high,
and pigtail is likely plugged,

By Ptrol, you mean pressure/psi?
What do you mean pigtail is plugged.

Jamie Hall

Ptrol -- that's the pressuretrol, the grey box in the first picture. What is wanted is to dial that indicator on the front down to just barely above the 05 mark. It's set at about 3 now, which is too high.

The fact that the boiler gets up to 10 on occasion on the none too accurate pressure gauge indicates that the pressuretrol isn't seeing the boiler pressure and thus isn't able to control the boiler. It's also why the vents hiss and occasionally spit. Lowering the pressure should help a lot -- but, sadly, it is possible that running on such high pressure may have damaged them and they may need to be replaced.

The pigtail is the curly pipe to which the pressuretrol is attached. It's very likely to be plugged, and may well be plugged all the way back into the boiler. It needs to be really free and clear.

datawaym8

Thank you @Jamie Hall and @neilc. I will try and report back.

datawaym8

I took out the pigtail. There was nasty build up. Cleaned it thoroughly. There were also some build up inside the boiler pipe too so that was also cleaned. The PSI level was adjusted to just a bit above 0.5 and the white wheel is set to 1 as seen in the photo.

Two concerns.

1. The boiler was able to run fine for 30 mins then PSI went up to like 6-7. What else could be the problem?

2. Then the boiler stopped running like it had reached the target temperature but when I looked at the thermostat, it hasn't. Less than a min later, it started back up again. I don't know the time gap but it happened again later I went down to check on the boiler. Is this behavior normal?

neilc

#1
6 and 7 is still too high, you're aiming for 2, tops, 1.5 is better

Jamie is more conservative than I am,
and Ptrols are notoriously, not precise,
I see room to lower that indicator more, try half way more to the bottom,
is there any chance the differential wheel is spun past 5, and around to 1 again?
that math might get you up to the 6/7 range,
see if it turns straight to 5, the 4, the 3, , , , to 1,
don't force the wheel, there are definite stops on it,
BTW, that wheel, differential wheel, is the # added to the scale "cut In", to set your "cut out"

we all should have mentioned,
there's a small hole at the bottom of the Ptrol,
that can gunk up also, did you check that, and clean?

were you able to blow thru the pigtail freely?
including back to the boiler?

#2
might be ok,
if it's the Ptrol working for you,
while it was starting and stopping, did you notice any slight click at the Ptrol microswitch?

or is your stat or a low water cut off?
did you notice water leaving the sightglass and returning? the higher pressure may have pushed water out of the boiler

EBEBRATT-Ed

@datawaym8

The pressure controls job is to keep the boiler from building too much pressure. Steam systems like yours are designed to run at 2 psi maximum (a little lower is better)

The setting on the pressure control that says 'CUT IN" is the pressure the burner will start at when the pressure drops.. You want that set as low as possible but if you set it too low the boiler may not start so be a little cautious and adjust slowly 1/4 turn at a time. The scale on the control s are inaccurate

The differential is the white wheel inside which should be set to 1-1 1/2.

Example: If the cut in is 1/2psi and diff is 1 psi boiler will shut off at 1 1/2 psi.


Steam systems calm down and work better at lower pressures

datawaym8

neilc said:

see if it turns straight to 5, the 4, the 3, , , , to 1,

No, it won't let me turn that way so I just left it at 1.

neilc said:

there's a small hole at the bottom of the Ptrol,
that can gunk up also, did you check that, and clean?

Did not check that part.

neilc said:

were you able to blow thru the pigtail freely?
including back to the boiler?

I blew through the pigtail with a bit of effort but didn't try while attached to the boiler.
We made sure the boiler pipe was cleaned of obstacle before attaching.

neilc said:

#2
might be ok,
if it's the Ptrol working for you,
while it was starting and stopping, did you notice any slight click at the Ptrol microswitch?

or is your stat or a low water cut off?
did you notice water leaving the sightglass and returning? the higher pressure may have pushed water out of the boiler

This is making me a nervous because I don't think this was happening prior to today.
Half an hour in, the boiler turns off again without reaching the target. The pressure seems to be at around 6 before it shuts off and drops it to 4-5. Something clicked and then whoosh, a loud fire burning sound started. Two mins later, shuts off again and lowered the pressure a bit. Less than 30 seconds later, it clicked and then whoosh loud fire burning started again. This kept repeating. I turned the radiator off thinking it might be unhealthy for the boiler.

Can't really tell from the picture but I have turned down the PSI setting even lower this time.


This is the water level after radiator was turned off.

datawaym8

EBEBRATT-Ed said:

@datawaym8
if you set it too low the boiler may not start so be a little cautious and adjust slowly 1/4 turn at a time. The scale on the control s are inaccurate

The differential is the white wheel inside which should be set to 1-1 1/2.

Example: If the cut in is 1/2psi and diff is 1 psi boiler will shut off at 1 1/2 psi.

Currently, I set the wheel to 1 and lowered the PSI control a bit. It does seem to lower the pressure but also because it kept shutting off the boiler before it can go any higher. It runs for 2 mins and shut off and the lowered the pressure a bit and turn back on after less than 30 seconds.

neilc

if you leave the boiler off a while, and all pressure dissipates,
does your gage settle back down to zero ?

lower that indicator by a full turn, counterclockwise,
ok?
then do it again,
ok?
one more time,

seriously bottom it out and see where you're at,
you can always bring it back up if I'm wrong,

that sightglass,
water looks dirty, cloudy,
needing skimming, and a full flush and emptying,
and repeat,

the quick on and offs,
cycling on the Ptrol,
where do you stand on main venting?

datawaym8

@neilc
Sorry. It took a while. We did a lot in the past weeks base on what I read in the forum. But the problem with the pressure/short cycling still exists.

neilc said:

if you leave the boiler off a while, and all pressure dissipates,
does your gage settle back down to zero ?

Yes

neilc said:

that sightglass,
water looks dirty, cloudy,
needing skimming, and a full flush and emptying,
and repeat,

We emptied the whole boiler and it was nasty. But as soon as we ran the boiler again, water seems to be dirty again but not as bad as before. We tested the water quality a week later, only the water that came out the first few seconds were dark. Maybe the condensation pipe is rusty?

neilc said:

the quick on and offs,
cycling on the Ptrol,
where do you stand on main venting?

At the drip line toward the opposite end of the boiler, there was a Gorton C. Today, I just replaced it with two Gorton No 1. When the heat is running for maybe half an hour, I can hear slight hissing sound from the newly installed Gorton No1 just as it did with the previous Gorton C. I assume it has to do with high pressure.

neilc said:

lower that indicator by a full turn, counterclockwise,
ok?
then do it again,
ok?
one more time,

seriously bottom it out and see where you're at,
you can always bring it back up if I'm wrong,

I bottomed it all the way and the pressure still goes up around 25 min mark before shutting off at 5. It used to go up to 10 so at 5 is a big change.



Worth noting that our boiler is a 240,000 BTU Burnham. I am suspecting it's oversized?
Also our boiler doesn't seem to have an aquastat to control the water temp. Would installing an aquastat help by any chance? We also replaced a great majority of the vent valves but one is still hissing water.

Here's some picture of my boiler.

Jamie Hall

Your boiler water quality -- at least what I can see from the sight glass -- is fine. No problems there.

Have you taken the cover off the pressuretrol to see what the interior white dial is set to?

If we assume that that pressure gauge is accurate -- a none to safe assumption -- 5 is still much too high. Pressuretrols are pretty reliable -- but have you made sure that the pigtail is really clear, right through to the boiler (you can blow through it easity)? And the opening at the base of the pressuretrol is clear?

One other test: open the pressuretrol cover, and take one of the two wires inside off its screw (note which screw it is connected to). Do this with the power off. Turn the power back on and turn up the thermostat. The boiler shouldn't fire. If the boiler fires with the pressuretrol disconnected, you have a serious safety hazard and that must be corrected.

Bottom line here. Your boiler may be oversized -- many of them are. You may still be undervented. Without a truly reliable pressure gauge, I can't say. In any case, neither of those factors will cause the pressure to rise that way. Either the pressuretrol isn't doing its thing or the gauge is unreliable.

datawaym8

Jamie Hall said:

Your boiler water quality -- at least what I can see from the sight glass -- is fine. No problems there.

Have you taken the cover off the pressuretrol to see what the interior white dial is set to?

If we assume that that pressure gauge is accurate -- a none to safe assumption -- 5 is still much too high. Pressuretrols are pretty reliable -- but have you made sure that the pigtail is really clear, right through to the boiler (you can blow through it easity)? And the opening at the base of the pressuretrol is clear?

One other test: open the pressuretrol cover, and take one of the two wires inside off its screw (note which screw it is connected to). Do this with the power off. Turn the power back on and turn up the thermostat. The boiler shouldn't fire. If the boiler fires with the pressuretrol disconnected, you have a serious safety hazard and that must be corrected.

Bottom line here. Your boiler may be oversized -- many of them are. You may still be undervented. Without a truly reliable pressure gauge, I can't say. In any case, neither of those factors will cause the pressure to rise that way. Either the pressuretrol isn't doing its thing or the gauge is unreliable.

White dial is set to 1.
We made sure the pigtail and the pressuretrol is clear.
I just performed the test with one wire off. It made a loud click with no fire on.
Under vented in the sense I need more Gortons at the drip pipe? This beast heats up the unit above the boiler so quick, we had to downsize the vent to 4 and 5 Maid o Mist.

Thanks for the feedbacks.

Jamie Hall

Somehow I had missed that your "main" vent is close to the boiler -- and is thus quite totally useless. That could possibly be a part of the problem. If you don't have crossover traps, the main vents need to be at the far ends of any steam mains, and whether you have crossovers or not the real main venting needs to be at the ends of the dry returns before they turn down to the wet return.

Also, the test for the operation of the pressuretrol isn't complete. Yes, you need to hear the click, but you also need to be sure that the boiler cannot fire when the pressuretrol is disconnected at one wire.

neilc

datawaym8 said:

White dial is set to 1.
We made sure the pigtail and the pressuretrol is clear.
I just performed the test with one wire off. It made a loud click with no fire on.
Under vented in the sense I need more Gortons at the drip pipe? This beast heats up the unit above the boiler so quick, we had to downsize the vent to 4 and 5 Maid o Mist.
Thanks for the feedbacks.

just so we're all clear,
there was no fire in the boiler while the wire was off the Ptrol,
and you had switched the service switch and thermostat back on ,
correct ?

the click came from the Ptrol ?
I'm not sure how if there was no boiler firing,
unless,
the Ptrol was still dropping trapped pressure,
are you certain the pipe and elbow under the pigtail are clean and clear all the way back into the boiler ? (blow test)
(sorry to beat this dead horse)

Jamie Hall

Let me try -- briefly -- one more time here. Turn the boiler off and let it cool. Now disconnect one of the two wires from the pressuretrol. Turn the boiler power back on. Turn the thermostat all the way up so you are definitely calling for heat. The boiler should not fire. Now turn the boiler power off again, reconnect that wire (make sure it goes on the same screw) and without touching the thermostat or anything else, turn the boiler power back on. The boiler now should fire.

What I am trying to find out is not does the pressuretrol click, but is the pressuretrol properly wired into the burner control circuit.

If it doesn't pass both of the above tests, it's not -- and you need to correct that before you use the boiler.

datawaym8

Jamie Hall said:

Now disconnect one of the two wires from the pressuretrol. Turn the boiler power back on. Turn the thermostat all the way up so you are definitely calling for heat. The boiler should not fire.

Check. A loud click with no fire.

Jamie Hall said:

Now turn the boiler power off again, reconnect that wire (make sure it goes on the same screw) and without touching the thermostat or anything else, turn the boiler power back on. The boiler now should fire.

Check. Fire did turn on by itself after reconnecting the wire and turning on power.

Jamie Hall said:

Somehow I had missed that your "main" vent is close to the boiler -- and is thus quite totally useless

Must be confusion generated from my part. The gorton 1s are installed in the room at the far opposite side of the boiler room. They are installed on what seems to be the drip pipe(I might be referencing it incorrectly). If you see the diagram below, that's where my main vent and the gorton 1s are located. There

Jamie Hall said:

whether you have crossovers or not the real main venting needs to be at the ends of the dry returns before they turn down to the wet return

Unfortunately, ours seem to be installed at the top of the vertical wet return pipe just after the 90 degree turn. Do you think this is a major problem? It was like this when we got the place.

neilc said:

are you certain the pipe and elbow under the pigtail are clean and clear all the way back into the boiler ? (blow test)
(sorry to beat this dead horse)

Pigtail is clean. I wash it with water and blew it multiple times from both ends.
We cleaned the pipe connected to the pigtail. Initially there were large build ups but now they were gone.
We even used a hose and aimed directly at the boiler pipe. We did the blow test, it was able to to go through.

Would you guys recommend me replacing the pressuretrol to a vaporstat?
I am looking at this Honeywell Vaporstat Controller (Steam), 0 to 16 oz/in2

Jamie Hall

We're making progress! Thank you for running that little test -- that reassures both you and me that the pressuretrol is wired correctly. They usually are, but... sometimes it's worth checking.

And sorry about the confusion about the main vent location -- that's fine as you've got it. It's sometimes hard to picture things from words...

I suspect that the next thing to do is to determine what the system pressure really is when the pressuretrol cuts out. Both pressure gauges and pressuretrols have been know to be out of calibration -- sometimes by a lot -- and it would be nice to know. There are inexpensive 0 to 5 psi gauges available from Amazon, of all places, and with a bit of plumbing you could mount one on the same pigtail as the pressuretrol and see what it said.

datawaym8

What if the pressuretrols is indeed out of calibration, what should I do then?

pecmsg

datawaym8 said:

What if the pressuretrols is indeed out of calibration, what should I do then?

The dial on most controls are generally out of calibration. This is why you us an accurate gauge to check it. 

datawaym8

@Jamie Hall Got a 0-5 psi gauge. It's showing the actual cut off at around 3.5 psi.

Jamie Hall

If the pressuretrol you are using there is set at 0.5 cutin and 1.5 cutout, then... either it's out of calibration or the pigtail is clogged -- and if it's on the same pigtail it's out of calibration. That's why you get the gauge.

Oh -- and 3.5 psi is too high.

datawaym8

Jamie Hall said:

If the pressuretrol you are using there is set at 0.5 cutin and 1.5 cutout, then... either it's out of calibration or the pigtail is clogged -- and if it's on the same pigtail it's out of calibration. That's why you get the gauge.

Oh -- and 3.5 psi is too high.

What should I do in this case? Get a new pressuretrol or vaporstat?
Also the gauge was sitting on 0 PSI for a good 24 mins before it starts lifting. Is this normal?

Jamie Hall

datawaym8 said:

Jamie Hall said:

If the pressuretrol you are using there is set at 0.5 cutin and 1.5 cutout, then... either it's out of calibration or the pigtail is clogged -- and if it's on the same pigtail it's out of calibration. That's why you get the gauge.

Oh -- and 3.5 psi is too high.

What should I do in this case? Get a new pressuretrol or vaporstat?
Also the gauge was sitting on 0 PSI for a good 24 mins before it starts lifting. Is this normal?

Possibly, although I believe there is a way to adjust the calibration, and
Yes. Quite normal.

neilc

datawaym8 said:

neilc said:

are you certain the pipe and elbow under the pigtail are clean and clear all the way back into the boiler ? (blow test)
(sorry to beat this dead horse)

Pigtail is clean. I wash it with water and blew it multiple times from both ends.
We cleaned the pipe connected to the pigtail. Initially there were large build ups but now they were gone.
We even used a hose and aimed directly at the boiler pipe. We did the blow test, it was able to to go through.

ok, pigtail is clear, you blew thru both ends,
But, what about the 90 below it, and the nipple and port back into the boiler?
can you blow back into the boiler thru the assembled pigtail and 90 ?
can you post another picture showing that new gage, and pigtail and Ptrol once again,
(how that's all assembled)
it's nice to have a second gage on a different port, so as to check one gage to another, not exact psi, but if both move at all,