Header pitch? Rads filling with water

CaptSkinny

I have water sloshing into my radiators, especially closest to the boiler, on a one-pipe steam system. I'm using DH's book to troubleshoot, and when checking pipe pitch I noticed that the header piping is perfectly horizontal. Shouldn't it be pitched toward the equalizer? Could the lack of pitch cause water to be carried into the main and rads? If so, is there a fix other than replacing that piping?

The sloshing water starts when the boiler gets up to steam and continues for the duration of the cycle. It's a new problem this heating season. The only change I've made from previous seasons is to replace the stem packing on a few leaking radiator shutoff valves, including one of the two rads that tend to fill with water.

I should note that the house has been settling quite a lot over the last 2-3 years, so it's entirely possible that the header did have a bit of pitch (though it couldn't have been much) when it was installed about 8 years ago.

ethicalpaul

The pitch isn't great, but in my opinion, almost no water should be getting to the header anyway. And I can tell you from personal observation that in normal operation condensate will flow backwards down the risers even when the boiler is steaming (but i do see in your case that the pitch is toward the header so possibly not happening in your case)

If water is getting into your main, I would much quicker suspect the water quality. Anything that introduced oils into your boiler water could be a cause. A simple skimming may clear this up for you.

But I also wonder about these radiator valves. It could be condensation not draining properly out of the radiators. Are the valves fully open as they should be? Is it possible the valve seal has separated from the valve and is flopping around at the bottom of the valve, blocking the condensate? Those are common things that can cause water to build up in radiators.

CaptSkinny

@ethicalpaul - Thanks, I'll give skimming a try.

All the valves are fully open, except for one second-floor radiator that is fully closed (otherwise it still heats with the adjustable vent on 'off' or upside down). The seals disintegrated long ago -- there's nothing in the valve body but I suppose there could pieces downstream, in the riser or the main. I tried and failed to snake my el-cheapo Amazon inspection camera through the 90-degree fittings to look for obstructions.

pecmsg

When was that piping done?

CaptSkinny

@pecmsg - the near-boiler piping was installed in 2010 with the boiler.

pecmsg

CaptSkinny said:

@pecmsg - the near-boiler piping was installed in 2010 with the boiler.

So what changed to create the issue. Any other work done recently?

CaptSkinny

@pecmsg said:

Any other work done recently?

No other changes, just the stem packing replacement (steam had been escaping from the stem and condensing on the outside of the valve) and possible shifting of the floor joists from settling of the house (the pitch of mains and returns is still OK). I did notice that the boiler water was still awfully rusty after my annual cleaning at the start of the season -- I seem to remember that in years past it looked nice and clear, with a brand-new sight glass, when they finished.

ethicalpaul

Yeah speaking of rust, it would be nice if they put some treatment in your water to get the ph up to 10 or so to reduce some of that rust. But figure out the water in the radiator problem first. One thing at a time

Chris_L

You should also check the pitch of the runouts to the radiators. They need to be pitched back to the boiler--along their entire length (no dips).
You might also try lifting all four legs of the radiators that are sloshing, and be sure they are pitched back towards the valve.

kenlmad

By chance, while repairing some of the valves did you use any penetrating oil?

Is it possible the person you hired to do your annual cleaning left some type of "cleaning agent" within the boiler or forget to drain & refill? You did state that the water remained rusty when compared to previous cleanings.

As @ethicalpaul suggested, drain + fill + skimming should be done. Hopefully that will fix the problem or at least eliminate "water quality" as the root cause.

CaptSkinny

Thanks, @kenlmad.

kenlmad said:

By chance, while repairing some of the valves did you use any penetrating oil?

No oil, but when the steam first hit the new stem packing there was a bit of graphite+condensate solution oozing from the top of the valve stem. So there's a good chance it was dripping downward into the valve body, too.

kenlmad said:

Is it possible the person you hired to do your annual cleaning left some type of "cleaning agent" within the boiler or forget to drain & refill? You did state that the water remained rusty when compared to previous cleanings.

He definitely didn't drain and refill. I drew some nasty water off the bottom and from the returns when I saw the rusty sight glass, but just until it was relatively clear. I suspect he was making up time due to an unanticipated burner repair, or forgot to finish the cleaning after fixing the burner.

I also lose a lot of water (another problem to be solved), so the boiler has seen about 30 gallons of new water since then. I'll look for skimming instructions on HH (I'm sure I've seen them before) and give that a try this weekend.

Jamie Hall

Hmm... back to square one here. We have, apparently, water sloshing in the radiators. There are two ways -- and only two -- that water can get into the radiators: it's being blown in with exceedingly wet steam, or it is from condensing steam. Now... in either case, it shouldn't slosh. At worst, it should, perhaps, gurgle or even hammer and burp a bit at the valve. But it shouldn't stay there. The radiator should be pitched so it drains out.

So ... step 1 here is to check that the radiators are, in fact, pitched to drain. Not that they will ever drain empty -- there is space below the inlet; can't help that. But they should be pitched towards the inlet somewhat, and drain freely.

Second step has been mentioned -- the radiator valves are fully open and are valves meant for steam (it is possible to get radiator valves which are not for steam, but hot water -- and which don't allow the condensate to drain).

Then the next thing to do (we're going backwards here) is to think about excessively wet steam and its effect. Which translates into making sure that the pitch of any horizontal bits of runout very close to the radiator is correct, and that the runouts themselves have enough capacity. If there is a problem in this regard, it is much more likely to show up as a water hammer than it is to show up as water being retained in the radiator -- but steam never fails to surprise, and this could be a problem.

Then steam mains. Assuming they are insulated, they won't add much condensate, but if the steam is very wet from the boiler, there will be water in there which has to go somewhere. Again, proper pitch is the key.

It is not entirely clear from the description whether the problem has always been there, but has become a more of a concern recently, or if the problem is recent. It would help to know that.

ethicalpaul

> I also lose a lot of water (another problem to be solved), so the boiler has seen about 30 gallons of new water since then

oh man since when?

CaptSkinny

Jamie Hall said:

check that the radiators are, in fact, pitched to drain...

making sure that the pitch of any horizontal bits of runout very close to the radiator is correct, and that the runouts themselves have enough capacity.

The offending radiators are pitched with a vengeance -- it's first thing I wanted to rule out. I've even removed them and flushed out any sediment with a hose. The runouts all come up at an angle with no horizontal component, I'm guessing 22.5 degrees. They're all 1-1/4, the same size as the radiator tapping.

Jamie Hall said:

much more likely to show up as a water hammer than it is to show up as water being retained in the radiator

I do get a bit of mild water hammer in the radiators that don't fill up with water, for only a few minutes after the system gets up to steam. And, strangely enough, well after the cycle is over in one radiator -- usually when I walk on the nearby floor (this radiator has a separate return line -- could be filled with sedement).

Jamie Hall said:

It is not entirely clear from the description whether the problem has always been there, but has become a more of a concern recently, or if the problem is recent. It would help to know that.

It's possible that some water was being retained to a smaller extent last season, but I didn't hear unambiguous sloshing, or radiators draining at the end of a cycle, like I do now. Earlier seasons aren't much of a basis for comparison because the vents were different and not particularly good at venting, so the radiators didn't see nearly as much steam or condensate as they do now.

CaptSkinny

ethicalpaul said:

> I also lose a lot of water (another problem to be solved), so the boiler has seen about 30 gallons of new water since then

oh man since when?

Since October 2020, when he reset the meter during the annual cleaning. I'm planning to replace the stem packing on the rest of the shutoff valves (the few I did replace were leaking steam, and the packing had turned to dust). Not quite sure what's next if that doesn't help.

neilc

and what of the pressure?
what are you set to, and what are you seeing on the gage when the boiler is boiling?
is pigtail clean? has it been checked?
post a picture of the Ptrol, pigtail, and sightglass,

CaptSkinny

@neilc - Good call, the (brass) pigtail is full of rusty sludge. The pressure gauge inlet was gummed up and keeping the needle stuck at 5 (I had naively assumed the gauge itself failed), so it only makes sense the pressuretrol inlet is gummed up, too. I cleaned the gauge inlet but the needle gummed right up with sludge again and doesn't give a proper reading. I'll take the pigtail off this week and clean the whole thing, but I wonder how long it'll stay clean with the iron fittings between the pigtail and boiler tapping.

The cut-in is set to about 1 psi, and differential is 1. I just noticed a couple other of things, too:

• When the cycle ended I heard water moving in the return verticals for about 5 minutes, then a main vent very close to the vertical drop expelled a lot of air under pressure. I wonder if water is stacking up to a point before the vent, blocking it. See last image below. The closest upstream radiator using that return is one of the rads filling with water.
  
• The sight glass leaks when the boiler cools down, so that may be the cause of the high water consumption. I've never noticed it wet before (only signs of previous leaking), but I forgot to turn the power back on to the boiler after cleaning and replacing the pressure gauge. When I realized it 5 hours later and went down to flip the switch, I saw the leak. I wonder if it's just evaporating when the boiler doesn't get a chance to cool down so much, so it never appears wet.
  

The heavy rust stain at the bottom of the sight glass is on the outside








Blocked vent:

Jamie Hall

I wonder how high your pressure really was getting? The behaviour of that vent certainly suggests that water was stacked up above it -- and that could also keep water from draining out of low flying radiators.

Remember that you need 28 inches for every pound of pressure...

neilc

one more large picture of that whole control side of the boiler,
looks like your pigtail is coming off a low point drain, under the normal water line,
or is that your skim tap ?
if that's under the water line, that's trouble right there and should get relocated above the water line, higher the better,
even if it gets plumbed into a new tee under the safety valve,
picture of the topside also , , ,

neilc

the mild hammering,
is it maybe expansion contraction noise?
either, or, both the pipe thru the floor, and the rad feet on the floor?
pipe hole should be daylight loose around the pipe,
and the feet can catch and release as the rads heat and cool,
milk jug plastic makes a good slip for isolating slippery-izing mild knocks, thru the floor and under feet,
I think of this because you said as you walk across that floor, after the heat shuts off,
shouldn't really get hammering after the fire

CaptSkinny

@neilc, yep, the pigtail is coming off a low point tapping under the normal water line. I took a look at the manual and it seems the LWCO belongs there (it's currently in the skim tapping). There are two plugged holes above the water line for the pressuretrol and pressure gauge. I think I'll wait a month or two to change it around when the weather improves and I have a larger window for error.

Re the mild hammering: I think you're right, a lot of is expansion/contraction noise, especially the one that knocks when I walk nearby. The hardwood isn't snug against the subfloor in some spots. It always sounded like expansion noise but couldn't imagine what was moving to cause the metallic sound. Now that your comment forced me to think it through I realize it's the union between the radiator and shutoff valves. One problem solved!

neilc

I would still check and clean that pigtail now,
and be sure you're open all the way back thru the iron into the boiler,

later when you relocate you'll be changing the wiring there also,
consider placing the Ptrol and gage up high with the safety valve as I suggested,
best yet, leave the 30 down where the manual suggests, and add a low, 0-3, or 0-5, up with the Ptrol

looks like you're running new wires either way.

CaptSkinny

Much appreciated, @neilc. Will do that.

What's the reason behind getting the ptrol and gauge up high? Further away from surging water?

Jamie Hall

CaptSkinny said:

Much appreciated, @neilc. Will do that.

What's the reason behind getting the ptrol and gauge up high? Further away from surging water?

Partly -- if not mostly -- but also if the pigtail is connected below the water line, the pressure gauge and the pressuretrol will be reading and reacting to the pressure of the steam plus the pressure due to the depth of water at their connection point. For most systems, operating around 1 psi maximum, this isn't important -- but for vapour systems, operating at at most a few ounces, it can be critical.

neilc

yes, stay / keep away from the water,

and now as you mention surging,
I'm wondering what a bouncing waterline could do to that Ptrol assembly that you currently have,

how much bounce have you seen?
and did you do that skim? or 2 or 3?

that pig loop looks close enough to the waterline that you could be pumping skim scum / dirty waters into the loop (?)

ethical Paul should set up a clear vision demonstration

SteamingatMohawk

Can anyone explain why the LWCO would be located at the skim port instead of lower according to the drawing? The only thing I can think of is if the LWCO is higher on the boiler, the minimum amount in the boiler would be greater. Does it have anything to do with oil vs. gas? Depending on the amount of water the VXT injects, the level after LWCO action would be higher than if the LWCO is lower. If the water level after fill is too high, could that be contributing to the problem? I suggest you check the feed settings on your VXT. Here's the manual for one, make sure it's for yours

https://hydrolevel.com/wp-content/uploads/2020/11/VXT-120-Instructions-web-111020.pdf

Perhaps, making the boiler "like the drawing" can take care of some of the other suggestions made in this discussion.

Like relocating the LWCO can make the small ports available for the pressure gauge and pressuretrol.

CaptSkinny

neilc said:

How much bounce have you seen?

None at all, but I suspect the fitting at the bottom of the sight glass is at least as plugged as the pigtail. I'll clean it out when I do the pigtail and replace the glass on Monday.

and did you do that skim? or 2 or 3?

I haven't yet. From what I discovered this weekend it seems I have to remove the LWCO to access the water line, and that's half the work needed to move everything to where it belongs. Maybe I'll keep an eye out for a mild day and get it all done sooner rather than later.

neilc

SteamingatMohawk said:

Can anyone explain why the LWCO would be located at the skim port instead of lower according to the drawing?

did not RTM

neilc

CaptSkinny said:

and did you do that skim? or 2 or 3?

I haven't yet. From what I discovered this weekend it seems I have to remove the LWCO to access the water line, and that's half the work needed to move everything to where it belongs.

good point

SteamingatMohawk

@neilc My reference to the VXT manual is to show the switches for selecting feeder settings.

The drawing I referred to is posted between two views of the boiler.

ethicalpaul

CaptSkinny said:

I haven't yet. From what I discovered this weekend it seems I have to remove the LWCO to access the water line, and that's half the work needed to move everything to where it belongs. Maybe I'll keep an eye out for a mild day and get it all done sooner rather than later.

When you get the LWCO moved where it belongs and get a nice skim pipe on there you are going to be in really better shape, it's a good project

CaptSkinny

Update -- after some cleaning on Monday the system seems to be running much better. No water hammer or whistling wet radiator vents. Water still builds up in one radiator but not to the same extent as before.

• Cleaned the ptrol inlet, pigtail and attached iron fittings per @neilc recommendation, and did a quick skim through that lower port. The iron was full of black sludge and hard deposits.
  
• Replaced the leaking sight glass and cleaned those valves as best I could without removing them. A lot of rust and some black sludge. I can see the water bouncing around now, probably a 1/2" - 3/4" wave. My guess is it's a bit more turbulent than it should be but I don't have a good basis for comparison.
  
• Flushed each of the return verticals with a hose attached to the main vent ports. Lots of sediment removed.
  
• Attached a new 4" 0-10 psi gauge I had around. Had to put it in the same spot as before -- ptrol is still blocking the designated tapping and that safety valve isn't coming off to put a tee under it (the riser is in the way). The needle oscillates a bit now the water movement but it still doesn't move past the first mark (1/5 PSI = 3.2 oz).
  

Also worth asking -- when I fired it back up I took a look at the firefox through the inspection glass and noticed a dark spidering pattern on the back wall that looks suspiciously like cracking. Is that anything to worry about? Maybe just some kind of insulating material against the walls that is cracked?