Dirty water in sight glass, how to flush?

ChicagoDIYer

I forgot to get my annual boiler maintenance before the heat season started and now the boiler companies are too busy with more urgent service calls and won't be able to come until spring. The water seems pretty dirty, and there's some mild water hammer when the boiler fires up. The last time I got it serviced (April 2022) the technician said I should drain the water occasionally, but I was scared to touch it so I never did. Now I own my home so I'm trying to do better. So I am thinking I should try to flush the water now and get it running cleaner until I can get a whole checkup in spring.

I'm not sure which is the valve I should drain it from. Can someone look at the pic and give me a clue? More questions: Do I drain it while the system is running or shut it off first? Should I drain the sight glass too, separately? I turned the knob at the bottom of the glass a couple times and nothing happened so I tightened it back.

It's a Green Mountain steam boiler, with an automatic water feeder and electronic LWCO, installed in 2021, one-pipe radiator system in a 120 year old house.

Mad Dog_2

Can you post some pictures 📷 of the return piping below the water line and behind the boiler?  Thanks Mad Dog 🐕 

109A_5

Hello @ChicagoDIYer,
The Red valves at the Red arrows should both be open or turned and basically remain CCW (Counter Clock Wise) to constantly monitor the boiler's water level. There is usually a drain (may require tools) at the bottom of the lower sight glass valve at the Green Arrow to drain and flush out the sight glass. A service tech might just remove the glass tube to clean it but it can break, probably why it is so rusty now, no one has cleaned it.

The valve and cap in the Yellow square is the Boiler drain. I would shut off the boiler and let the boiler cool down quite a bit before draining and refilling it with cold water. There may be other drains not in the pictures.

The pigtail pipe, Orange arrow, should be kept clean inside too.

109A_5

Hello @ChicagoDIYer,
Could the water be relatively clean and the sight glass tube is just very dirty ?

neilc

and are we all SKIMMING over the skim port ?
what an opportunity , , ,

Neild5

@neilc, you beat me to it!  

Neild5

Could you get a picture of the top of the black vertical pipe and the header it connects to?  Also the pressuretrol, the box mounted on the pigtail.  If you could take the cover off for the picture it would show both of the control settings. 

ChicagoDIYer

Sorry for the delay, I didn't realize I had gotten replies! Just changed my notification settings to email me.

Adding pics of the pipes and pressuretrol 

ChicagoDIYer

ChicagoDIYer

@109A_5 thank you for the diagram and explanation! Super helpful.

Yes it could definitely be that the water is clean and the sight glass is dirty. In the small area where I'm able to look through the water, it is clear. I just figured it must be dirty for the sight glass to be so dirty. 

KC_Jones

The boiler piping is incorrect. If I'm reading the model correctly that is a GMGS187E (please confirm). If it is it requires both tappings be piped and that both be pipe full size (2 1/2" pipe). Even if it was a smaller one, the tapping is to be full sized, yours is reduced right at the boiler. If you are getting hammer, I would suggest that incorrect piping is a contributing factor. Also the header format is incorrect, though I would deem that a slightly lesser problem. The pinch point is right at the boiler and will impact overall performance and efficiency.

The incorrect piping can contribute to excess water carry over into the system and amplify any water hammer issues you are having, or could be the entire hammer issue you are having. For now you would need to use a level and string and check all pipes for proper pitch and use the string to verify you have no sags.

I also notice the water feeder is showing 444 gallons of water added, that's more than I would expect in the entire lifetime of the boiler and tells me you have either been removing a lot of water needlessly, or you have some very serious leaks. The excess water is a problem as it brings oxygen, leading to excess corrosion, and shortening boiler life. I have a boiler that is on it's 10th season and I'm at 52 gallons for reference.

I marked up a picture to show how it's supposed to look, and a screenshot of the manual. I highlighted in blue the part in the manual that doesn't show in your photo very well, that offset is important.

109A_5

Hello @ChicagoDIYer,

KC_Jones said:

I also notice the water feeder is showing 444 gallons of water added, that's more than I would expect in the entire lifetime of the boiler and tells me you have either been removing a lot of water needlessly, or you have some very serious leaks. The excess water is a problem as it brings oxygen, leading to excess corrosion, and shortening boiler life. I have a boiler that is on it's 10th season and I'm at 52 gallons for reference.

Yes, that is kind of crazy. It is like the CycleGard is telling the VXT to add water for the boiler continuously for 18.5 days. Although I believe that a continuous fill type behavior causes an error with the VXT.
The VXT is a timer that counts minutes. There is an orifice that at average municipal water pressure lets a gallon of water flow in a minute, so 1 gallon per minute. Could the magnetic valve of the VXT be plugged up ?

109A_5

Hello @ChicagoDIYer,
Where does this go ? Is it part of the wet return ? Could it be leaking underground ?

ChicagoDIYer

Oh ****.
So the number on the water feeder is the total amount of water that has been added over time?
That photo was taken Nov 2. Today the number says 457

@KC_Jones correct, that is my model number.

@109A_5 I don't know where that pipe goes! This is in the middle of my basement, so it's going somewhere underground?

Waitaminute - how does the water get added to the boiler? The water feeder connects to the pipe that's going into the ground on the right, and on the left there's a hump it would have to go over to get into the boiler.

Adding more pics below in case it's helpful, I'm starting to get an idea of what y'all are looking for.

ChicagoDIYer

ChicagoDIYer

oh also @KC_Jones about the piping, yeah the pipe coming out at the top (steam?) is 2.5 inches, but the one going in the bottom (water?) is 2"
I'm a little confused about what I'm supposed to check re: the pitch, but I will read more and I also looked up the manual.

KC_Jones

The pipe I highlighted red is 2” pipe (2 3/8” OD), I can see the two on the fitting, that is supposed to be 2 1/2” pipe (2 7/8” OD), and the connection on the other side of that boiler is supposed to be connected as well. Circled in blue is a bushing changing the size from 2 1/2” to 2”, and shouldn’t be there. Second picture I circled the plug that should have been pulled and piping connected.

You appear to have an underground return pipe going into the floor, and based on what I see it could be leaking, but I don’t live there so can’t say for sure. If you can’t find any other leaks of water or steam, that would be my first guess. If it’s leaking, that is a very big problem and will need fixed. Several options on that one.

First I wouldn’t think about going under the concrete again. If a new return is run it can be run at floor level, above the concrete. Another option if you have enough height (looks like you might) is run it as an overhead return that drops to the floor, straight down, near the boiler.

Your assessment of how water gets in is correct. It does go over the hump (Hartford loop) to get into the boiler. Pipe at and under the floor is the wet return.

109A_5

Hello @ChicagoDIYer,
I don't see a valve to totally shut off the water to the boiler only, just a valve to bypass the VXT. If you can totally shut off the water to the boiler and closely monitor how fast the water level drops, and if it stops dropping at the height of the Hartford loop.

Are there other pipes going underground in other parts of the basement or crawl spaces that would connect to the one coming up through the floor next to the boiler ?

ChicagoDIYer

@KC_Jones ok got it, pipes measured by internal diameter, thank you.

and @109A_5 I found where the pipe comes out!! it's about 10 feet away on the other side of the basement, goes along the wall and then behind the wall where it passes by a bathroom, then comes out and connects to the steam pipes that go up to the radiators. Pics below.

I haven't seen evidence of leaks anywhere in the house, so I think the underground pipe is a good bet. It could also be behind in the ~10 foot length that it runs behind the wall I guess. If the return can't be re-routed overhead, I'd be fine with it going across the floor in the basement.

109A_5

Hello @ChicagoDIYer,
Does water ever drain out of here ? Does the other drain pipe to the Right have anything to do with the steam system ?

ChicagoDIYer

@109A_5 You found something!! The pipe on the left is definitely draining, pretty sure it's connected to the steam system although I don't know what it connects to once it goes up into the wall. The pipe on the left is a little damp but not dripping. I took a video here, hopefully this works.

109A_5

Hello @ChicagoDIYer,
Your system sure has some oddities. I suspect the round device to the Left with the Hex shaped cap is a radiator steam trap being used like a Big Mouth main vent. It should be above the main so that very little condensate is lost. The other pipe to the right may be a return from a radiator on the floors above. If so it should be properly connected to the system so the condensate is returned to the boiler. Maybe they once were connected together ? So that was a steam trap for a radiator on an above floor.

All condensate should be returned to the boiler. Almost constant make up water will greatly shorten the boiler's life.

This little up hill piping is not helping either, a good place for mud to collect and restrict the wet return. That whole wet return should have proper valving so it can be flushed out as needed. Is the underground pipe all copper ? It looks like copper at the one end, it may have been replaced. Looks like the floor may have been repaired too.




Not sure why this check valve is needed here.



Where does this pipe go to ? Is there a main vent up there ?

Steamhead

KC_Jones said:

The boiler piping is incorrect. If I'm reading the model correctly that is a GMGS187E (please confirm). If it is it requires both tappings be piped and that both be pipe full size (2 1/2" pipe). Even if it was a smaller one, the tapping is to be full sized, yours is reduced right at the boiler. If you are getting hammer, I would suggest that incorrect piping is a contributing factor. Also the header format is incorrect, though I would deem that a slightly lesser problem. The pinch point is right at the boiler and will impact overall performance and efficiency.

The incorrect piping can contribute to excess water carry over into the system and amplify any water hammer issues you are having, or could be the entire hammer issue you are having. For now you would need to use a level and string and check all pipes for proper pitch and use the string to verify you have no sags.

I also notice the water feeder is showing 444 gallons of water added, that's more than I would expect in the entire lifetime of the boiler and tells me you have either been removing a lot of water needlessly, or you have some very serious leaks. The excess water is a problem as it brings oxygen, leading to excess corrosion, and shortening boiler life. I have a boiler that is on it's 10th season and I'm at 52 gallons for reference.

I marked up a picture to show how it's supposed to look, and a screenshot of the manual. I highlighted in blue the part in the manual that doesn't show in your photo very well, that offset is important.

This.