End of Main Vent pouring water

JS41190

Hello everyone. I am having a bit of trouble with an end of main vent dumping a lot of water while running.
The boiler was installed new in 2014 and has had minimal issues since then. The occasional end of main vent needed to be replaced but nothing unusual. According to the homeowner, the leaking vent has been worse than ever. 

Upon arrival yesterday (3/6/24) we found the pressuretrol to be leaking within, so we replaced with a new Honeywell PA404A1033 with the cut-in set to .5psi. The returns are all pitched correctly and clear. I took apart the return manifold and drops into the manifold to make sure they were clear. There is no surging going on in the boiler either. Nothing in the house has changed besides the end of mains. 

We were thinking the supply piping and equalizer are not correct, but again, it’s been fine for years. 

I am officially lost as to what could be the issue. I will attach pictures, and thank you in advance! (This is not my work so please don’t judge hahaha!)

ethicalpaul

It doesn't seem like you included a picture of the main vent situation.

But additionally, how do you know it isn't surging? That near-boiler piping is a surge generating machine

JS41190

Sorry, I guess I didnt take a close up. In the 4th picture you can see the coffee can over the end of main. It’s on the run of the tee with the bull facing up.

Also, I am just going by the sight glass as far as surging goes. 

ethicalpaul

I would ask for a closer picture, and without the coffee can on it, but it seems OK placement...how much water and when during the call for heat are we talking about?

So you are saying the water level stays constant in the gauge glass?

Jamie Hall

Realistically, let's think like water Just downstream from that coffee can there is what appears to be drip -- which is probably needed, if that main is pitched towards the boiler. If there's water coming out of that vent, there's water in that main. If there's water in that main, it should be going down the drip. Why isn't it?

JS41190

ethicalpaul said:

I would ask for a closer picture, and without the coffee can on it, but it seems OK placement...how much water and when during the call for heat are we talking about? So you are saying the water level stays constant in the gauge glass?

So the placement I believe is good. The air will release from the vent, as the return water comes back and all the air is released, the water will POUR out. From initial start up on a cold boiler, to the time the vent leaks is about 10-15 minutes. The water in the gauge glass will move, but not to the point where you can’t see if. I’d say it bobbs up and down maybe 1-2”, then again, the boiler will shut down around the same time it starts dumping water. 

JS41190

Jamie Hall said:

Realistically, let's think like water Just downstream from that coffee can there is what appears to be drip -- which is probably needed, if that main is pitched towards the boiler. If there's water coming out of that vent, there's water in that main. If there's water in that main, it should be going down the drip. Why isn't it?

I concur. I took apart the 1-1/4” union on that return main and ran a little snake up it, and down it, poured water and checked for any blockages. There was nothing in the line. It was surprisingly clean. I even took apart the 2” x 3/4” black bushing on the return manifold and cleared that out. I also filled the boiler with a washing machine hose connected to the same boiler drain on the return and saw it was filling in the gauge glass. Just so I know the Hartford Loop is clear, which it is. 

Steamhead

The steam piping leaving the boiler is wrong. Check the instruction manual for the correct piping diagram. Some water will always try to get out of the boiler with the steam, and the proper piping will stop this.

ethicalpaul

The air will release from the vent, as the return water comes back and all the air is released, the water will POUR out. From initial start up on a cold boiler, to the time the vent leaks is about 10-15 minutes. The water in the gauge glass will move, but not to the point where you can’t see if. I’d say it bobbs up and down maybe 1-2”, then again, the boiler will shut down around the same time it starts dumping water.

Several things in here caught my eye:

1. The water should be coming back way before the vent closes to steam (when the air is pushed out of the main) because the steam will start condensing from heating the main as soon as it starts being produced.
2. 2" is too much. You are probably surging (see @Steamhead reply above)
3. People always go to clogged pipes as a first thing, but it's almost never the thing. The normal condensate return is not very much volume of water. If vents are spewing (and not just an occasional drip), it is almost always boiler water from surging IMO
4. What did you mean by "then again, the boiler will shut down around the same time it starts dumping water"? Is this because the call for heat is satisfied? Or is it shutting down for some other reason?

JS41190

ethicalpaul said:

The air will release from the vent, as the return water comes back and all the air is released, the water will POUR out. From initial start up on a cold boiler, to the time the vent leaks is about 10-15 minutes. The water in the gauge glass will move, but not to the point where you can’t see if. I’d say it bobbs up and down maybe 1-2”, then again, the boiler will shut down around the same time it starts dumping water.

Several things in here caught my eye: 1. The water should be coming back way before the vent closes to steam (when the air is pushed out of the main) because the steam will start condensing from heating the main as soon as it starts being produced. 2. 2" is too much. You are probably surging (see @Steamhead reply above) 3. People always go to clogged pipes as a first thing, but it's almost never the thing. The normal condensate return is not very much volume of water. If vents are spewing (and not just an occasional drip), it is almost always boiler water from surging IMO 4. What did you mean by "then again, the boiler will shut down around the same time it starts dumping water"? Is this because the call for heat is satisfied? Or is it shutting down for some other reason?

So I am not sure why it shut’s down. It definitely isnt because the call for heat is satisfied though. I will add some Steam Clean to see if the surging subsides, unless there is another product you’d recommend. 

I advised the homeowner to have us repipe it correctly but obviously I can’t force them to do anything. 

I will try skimming/steam clean and report back. 

Jamie Hall

Is perhaps "pouring out" a little misleading? I can see a variety of reasons why a main vent might spit as condensate might not be able to make it down the drip fast enough, particularly on start up -- but pouring out is a different critter, and suggests to me that a) water is accumulating or being pushed up into that area of the main and b) the vent has failed so that it doesn't close on liquid water.

Now if it's annoying spitting, that's one thing, and I can think of two things which would help, as the problem would be condensate not being able to drain fast enough. The easy one is... are all the mains insulated? That would reduce the amount of condensate you have to deal with. If they aren't, they should be anyway -- and that is the place I would start. And it might be sufficient all by itself. Otherwise you could make that drip a bigger pipe size -- or relocate it so it is bigger (same size as the main) and placed before the vent.

JS41190

Jamie Hall said:

Is perhaps "pouring out" a little misleading? I can see a variety of reasons why a main vent might spit as condensate might not be able to make it down the drip fast enough, particularly on start up -- but pouring out is a different critter, and suggests to me that a) water is accumulating or being pushed up into that area of the main and b) the vent has failed so that it doesn't close on liquid water. Now if it's annoying spitting, that's one thing, and I can think of two things which would help, as the problem would be condensate not being able to drain fast enough. The easy one is... are all the mains insulated? That would reduce the amount of condensate you have to deal with. If they aren't, they should be anyway -- and that is the place I would start. And it might be sufficient all by itself. Otherwise you could make that drip a bigger pipe size -- or relocate it so it is bigger (same size as the main) and placed before the vent.

No it’s not spitting, it is literally filling a drinking cup in a matter of seconds. The vent is brand new, I replaced it. The return is 1-1/4” draining into a larger 2” manifold. Nothing is insulated on the return so I can try insulating that as well. 

pedmec

Well, from my point of view you have some issues with the near boiler piping. It's absolutely not correct but with you having said that it's never giving you a problem i'm going to give you the benefit of the doubt. i wouldn't add chemicals. I would flush the water out and start over. it won't cost you anything. you might have high levels of TDS in the water. By flushing the boiler you are removing the TDS and starting fresh. if that takes care of the problem then your in good shape. i believe it's going to be TDS because you can't see it and it will cause uneven water levels in your boiler. so it could be throwing lots of water and wet steam up the riser but with that bullhead tee its just causing lots of condensation.

ethicalpaul

Insulating the pipes won't help you.

As @pedmec said, forget the water treatment until you have it running well on just water.

JS41190

pedmec said:

Well, from my point of view you have some issues with the near boiler piping. It's absolutely not correct but with you having said that it's never giving you a problem i'm going to give you the benefit of the doubt. i wouldn't add chemicals. I would flush the water out and start over. it won't cost you anything. you might have high levels of TDS in the water. By flushing the boiler you are removing the TDS and starting fresh. if that takes care of the problem then your in good shape. i believe it's going to be TDS because you can't see it and it will cause uneven water levels in your boiler. so it could be throwing lots of water and wet steam up the riser but with that bullhead tee its just causing lots of condensation.

The homeowner drains down the boiler weekly he said, which I told him to stop doing. Also he mentioned, and showed me, he has a Talenti Gelato container about 1/4 full of metal flakes and debris from within the boiler from over the years. There are 3 or 4 of these jars with the same amount. 

So if I understand you correctly, you’re saying just remove all water from the boiler and add new to see if it helps? 

STEAM DOCTOR

I would put some eight way in there. Let it boil for an hour or so. Drained it out. Very very thoroughly. Meaning refill and drain a whole bunch of times. To make sure you really get everything else. See what happens