Water level in Sight Glass -Steam Boiler

kevinjames79

Recently i have noticed that when the boiler starts, after few minutes, the water level in the sight glass goes very low that i cannot see any water. At that time my low pressure guage shows me a pressure of a little above 1 PSI. After few minutes of running, pressure comes down and the water level comes back up.

This goes on for few minutes until the water level becomes stable at the bottom of the sight glass where i can barely see water in there. Remember that before the boiler started running, water was at the normal water line.

Could you please tell me whats going on here?

Thank you for the forum and all the wonderful people helping out.

ethicalpaul

Two things come to my mind immediately:

1. How is your main venting (is this a one-pipe system)?
2. How is your near boiler piping? It sounds like boiler water is getting thrown up into your main during part or all of your burn cycle. Please send some pictures of your boiler from a few feet away showing all the nearby piping.

kevinjames79

ethicalpaul said:

Two things come to my mind immediately:

1. How is your main venting (is this a one-pipe system)?
2. How is your near boiler piping? It sounds like boiler water is getting thrown up into your main during part or all of your burn cycle. Please send some pictures of your boiler from a few feet away showing all the nearby piping.

One Pipe System. Two mains with Bigmouths at the end of each main.

kevinjames79

ethicalpaul said:

Two things come to my mind immediately:

1. How is your main venting (is this a one-pipe system)?
2. How is your near boiler piping? It sounds like boiler water is getting thrown up into your main during part or all of your burn cycle. Please send some pictures of your boiler from a few feet away showing all the nearby piping.

What may be the reason of boiler water being thrown up into main?

ImYoungxD

kevinjames79 said:

ethicalpaul said:

Two things come to my mind immediately:

1. How is your main venting (is this a one-pipe system)?
2. How is your near boiler piping? It sounds like boiler water is getting thrown up into your main during part or all of your burn cycle. Please send some pictures of your boiler from a few feet away showing all the nearby piping.

What may be the reason of boiler water being thrown up into main?

Dirty or oily water - Did you install a new boiler, new radiator or replace pipes? New boilers, rad, pipes have oil inside them. You'll have to skim your boiler.

Bad piping - need pictures.

Are your valves on the glass fully open?

kevinjames79

I did install couple of new radiators.

It seems skimming is needed. and i don't even have a skim port. I may have to use the Pressure Relieve Value port.

ethicalpaul

It could be skimming and/or the other things still.

If they were really new, and not just new-to-you, then they could have had quite a bit of oil in them. My new one did.

If you send some pics, we might be able to help find a good place to port

kevinjames79

ethicalpaul said:

It could be skimming and/or the other things still.

If they were really new, and not just new-to-you, then they could have had quite a bit of oil in them. My new one did.

If you send some pics, we might be able to help find a good place to port

Koan

I will bet the nipple sticking out the top is the original location of the pressure relief valve (PRV) , and that the PRV is now plumbed into the skim port. You could probably easily relocate the PRV and have a permanent skim port where your PRV is now.

Fred

Skim the boiler. That will likely fix the problem. When oils lay on the surface of the boiler water, steam bubbles can't get through to release steam. It then starts to push the water out through the wet returns. As soon as the boiler ends a heat cycle, the water immediately returns to the boiler and the water level is back where it should be. A good, slow skim fixes that. It has to be a skim, not a drain and refill as the oils will cling to the sides of the boiler as the water is drained.

ethicalpaul

I think this is a peerless and the skim port is hiding behind (to the right of) the top sight glass port. The capped top port is a second steam supply, right?

My amateur eye is relieved to see what looks like good near-boiler piping, congratulations!!

Fred

@ethicalpaul , your eyes are better than mine. I didn't see that plugged skim port until you pointed it out.

ethicalpaul

I had to consult with the Peerless layout PDF to find it

kevinjames79

> @ethicalpaul said:
> I had to consult with the Peerless layout PDF to find it

Thank you guys. So all i have to do it open that plug and put a valve?

ethicalpaul

If you do a search on this site and/or on youtube you'll see a few descriptions and setups that will work for you.

On mine, I put a nipple to extend it away from the boiler, a full-port valve, and a Tee to let me watch the water flow out. Use pipe the same size as your skim port--don't reduce it

https://us.v-cdn.net/5021738/uploads/editor/es/9kswi70anqcb.jpeg

^^^ so much extra tape, plus the tape isn't even needed after the valve LOL I'll say I was practicing making joints

kevinjames79

> @Fred said:
> Skim the boiler. That will likely fix the problem. When oils lay on the surface of the boiler water, steam bubbles can't get through to release steam. It then starts to push the water out through the wet returns. As soon as the boiler ends a heat cycle, the water immediately returns to the boiler and the water level is back where it should be. A good, slow skim fixes that. It has to be a skim, not a drain and refill as the oils will cling to the sides of the boiler as the water is drained.

Skim started. I heated the water until steam was about to start. Then waited for 15 min and opened the port. Now water is slowly trickling. How much should i do this? Is 2 hours enough or more?

Fred

@kevinjames79 , two hours is a good start . You may have to do it a few times but just let it trickle as slowly as possible. The more calm you can keep the surface water, the better.

kevinjames79

> @Fred said:
> @kevinjames79 , two hours is a good start . You may have to do it a few times but just let it trickle as slowly as possible. The more calm you can keep the surface water, the better.

Thank you Fred. Doing it very slow

ethicalpaul

That was fast action on your part! Was there any gunk floating on top of the water as it flowed out? (although you can't always see the oil)

kevinjames79

ethicalpaul said:

That was fast action on your part! Was there any gunk floating on top of the water as it flowed out? (although you can't always see the oil)

lol. It was just scary seeing the sight glass completely empty when boiler was running. So wanted to do this as soon as possible. And all of you guys are so awesome here. Thank you for that.

So i did the Skimming part. I also spent an hour extra and emptied the boiler 3 times. Skimming took a long time I spent about 2 1/2 hours on it. The water in the first bucket of skimming did look thicker than normal. Is repeat skimming needed?

I also took apart the pigtail and verified that it was not clogged.

Here are the benefits i got of all this work

1) Water in the guage is now stable. No big movements. Water is also not disappearing from the sight glass.

2) Magically, my new Pressuretrol seem to be working. Although it may need some calibration. I have it set at 0.5 and cut off is 1. So technically it should cutoff at 1.5 But it does it at 2 (if i run the boiler long enough). But at least it does cutoff.

ethicalpaul

That's all great news!

I think if your waterline is stable, you've skimmed enough. If it acts up in the future, skim again, and you can collect some skim water (before it drops in the bucket) and boil it on your stove to see if it foams or makes bubbles. I've never tried this, only read about it. It should boil cleanly without foam.

I wouldn't worry about further calibration of the p-troll, they are notoriously course in their control, and that's because they are safety control where 1/2 psi isn't an unacceptable tolerance.

Does it get to 2 psi during a normal call for heat?

PS: IMO watch your system cycle a bunch more times to make SURE the p-troll is functional.

Fred

@kevinjames79 , glad the skim did the job! Also, if the Pressuretrol magically started working, my guess is there is a loose or broken wire that just happens to be making contact now. keep an eye on it (although that may be difficult given it only functions when pressure gets above the 2PSI). If it were me, I'd just replace the wire that connects it to your other safeties. Good Job!

kevinjames79

> @ethicalpaul said:
> That's all great news!
>
> I think if your waterline is stable, you've skimmed enough. If it acts up in the future, skim again, and you can collect some skim water (before it drops in the bucket) and boil it on your stove to see if it foams or makes bubbles. I've never tried this, only read about it. It should boil cleanly without foam.
>
> I wouldn't worry about further calibration of the p-troll, they are notoriously course in their control, and that's because they are safety control where 1/2 psi isn't an unacceptable tolerance.
>
> Does it get to 2 psi during a normal call for heat?
>
> PS: IMO watch your system cycle a bunch more times to make SURE the p-troll is functional.

When i boiled the water from boiler, i see white foam on top. Whay does this mean?

Fred

@kevinjames79 said: When i boiled the water from boiler, i see white foam on top. What does this mean?

It typically means there are still some oils in the water but if the water level in the sight glass is stable, probably not enough to be a problem. You may want to skim again at some time.

kevinjames79

> @Fred said:
> @kevinjames79 said: When i boiled the water from boiler, i see white foam on top. What does this mean?
>
> It typically means there are still some oils in the water but if the water level in the sight glass is stable, probably not enough to be a problem. You may want to skim again at some time.

> @Fred said:
> @kevinjames79 said: When i boiled the water from boiler, i see white foam on top. What does this mean?
>
> It typically means there are still some oils in the water but if the water level in the sight glass is stable, probably not enough to be a problem. You may want to skim again at some time.

Water level started going up and down again, so i am skiming again right now. I also installed the skim port with ball valvle for future.

Fred

Great. you will always have a need for a function skim port, albeit infrequently. Put a cap or plug on the end of the ball valve so that kids (both large and small) don't get curious and open it while the boiler is running.

kevinjames79

> @Fred said:
> Great. you will always have a need for a function skim port, albeit infrequently. Put a cap or plug on the end of the ball valve so that kids (both large and small) don't get curious and open it while the boiler is running.

Got it. I bought a plug too just for that 😉

kevinjames79

> @kevinjames79 said:
> > @Fred said:
> > Great. you will always have a need for a function skim port, albeit infrequently. Put a cap or plug on the end of the ball valve so that kids (both large and small) don't get curious and open it while the boiler is running.
>
> Got it. I bought a plug too just for that 😉

Fred..... I have another question for thw pros here. Plz take a look at the picture of the near boiler piping. I have one big pipe coming ng from the boiler. From this pipe, two main lines go to my house.
First lines comes from a tee from the boiler pipe. Second main line also comes from the same boiler pipe.

Does this mean that when the steam comes out, all steam goes to the first main line because it comes first. Second main line only gets the steam when thw first main line is full.

Is this true?

Fred

@kevinjames79 , What model is that boiler? It would have been nicer if they had used both riser tappings out of the boiler and if they had used a header that was one size larger than the boiler riser but if the installation manual says one riser is adequate and the diameter of the header pipe meets minimum requirements, it should be fine. Both mains will draw their share of steam.

ethicalpaul

Your near boiler piping looks fantastic compared to mine and so many others

The steam will go to where the pressure is lowest, which should ride a nice balance between those risers and would probably appear like simultaneous filling to any observer (depending on the vent situation on each main of course!)