Low Water Cutoff Makes Boiler Cycle every 3 minutes

levij06

Hello, steam heat elders,

100-Year-Old house with single pipe steam serving 13 radiators on 3 floors, Weil McLain EG/PEG 55 boiler in basement. We moved in 2 years ago and the heat worked fine - We had a bit of banging on one radiator, but nothing serious.

We got our basement finished this summer, and against my better judgment, I allowed the GC to have the plumber move a few of the pipes. Hard to describe exactly what he did, but I believe he moved a couple of the supply pipes higher (though they are still pitched correctly), changed the location of a vertical return from those supply pipes by a few feet, and put in a new vent (or maybe just replaced one that was at the corner of the supply pipe and the vertical return).

Now our system is not doing well. The main problem I think is that our system shuts off every 2 to 3 minutes due to low water cutoff. Then it stays off for like a minute and then turns back on. We do not have an automatic feed. I observed the water level surging a bit and rapidly going down through the sight glass. When the LWCO kicks in, the water level rises quickly in the glass, then the boiler turns back on within 30 seconds to 1 minute.

Other symptoms: 1) extremely violent banging in various parts of the system, 2) One of the radiators sometimes shoots Rusty water out of the vent on the far side of the radiator, and 3) at times, it takes hours for the furthest radiators to start getting hot.

I assume these other symptoms are actually just a symptom of the system cycling every 2 to 3 minutes. I figure the banging is the new steam hitting the condensate in the pipes that hasn't had time to return yet since the boiler was only off for a minute. And obviously, if the boiler is only on for 2 to 3 minutes at a time, I can imagine that would make it take a lot longer for the far radiators to get heat. Not sure about the radiator spitting water or if/ how that might be related.

Now I'm trying to understand why my boiler would be behaving this way suddenly. It may or may not be related to the work we had done this summer, so don't over index on that. Actually the system seemed to be working pretty well early in the fall, but as it's colder, it seems to be getting worse and worse.

I had an hvac company come out about the banging, and they studied the system for a few hours and told me my return lines were clogged. Then they sent someone else out who studied the system for another few hours, and they told me that that actually the problem is my near boiler piping is all wrong. (This was not changed by the basement guys). They told me I need two 3-in pipes coming up from the boiler but I only have one. They want to charge me $11,000 to fix the near boiler piping and they say this will prevent the low water cut off from tripping every few minutes because it will Make it so the steam leaving the boiler is at lower velocity and doesn't take so much water with it.

However, when I look at the manual for my boiler, it recommends a single 3-in pipe. I'm very skeptical that it's a good idea to pay $11,000 in order to change something away from the recommended specs.

I don't understand any other reason why my boiler is suddenly behaving this way.

Would love any help, and or recommendations for knowledgeable steam heat experts near Essex county New Jersey.

Thank you!

pecmsg

levij06 said:

Hello, steam heat elders,

100-Year-Old house with single pipe steam serving 13 radiators on 3 floors, Weil McLain EG/PEG 55 boiler in basement. We moved in 2 years ago and the heat worked fine - We had a bit of banging on one radiator, but nothing serious.

We got our basement finished this summer, and against my better judgment, I allowed the GC to have the plumber move a few of the pipes. Hard to describe exactly what he did, but I believe he moved a couple of the supply pipes higher (though they are still pitched correctly), changed the location of a vertical return from those supply pipes by a few feet, and put in a new vent (or maybe just replaced one that was at the corner of the supply pipe and the vertical return).

Now inform the GC you're going to hire a Steam contractor to repair all the mistakes and he gets to pay the bill!

neilc

can you show from your header, to the ceiling, so we see the mains,
you said counterflow,
show from the header, to the mains at the ceiling, and to the counterflow drips,
the drips don't seem to show in these pictures

Chris_L

I observed the water level surging a bit and rapidly going down through the sight glass.
Did the contractor skim the boiler after doing all the pipe work? The top of your sight glass looks filthy.

I'd suggest starting with the easy (and cheap) stuff first to see if that solves your problem.

ethicalpaul

Yeah if they did new piping they probably introduced oil into the system and now the water is surging (frothing during boiling basically, forcing water out the steam supply). I agree with @Chris_L, skim it.

JUGHNE

Can you show the pipes that were relocated?

You may not have a counter flow system as there are 2 wet returns on the floor.

Ironman

This is who I’d highly recommend that you contact: @EzzyT.

EBEBRATT-Ed

I agree send @EzzyT a message or call him.

You may have some skimming to do or not. The plumber probably screwed something up.

Your piping isn't great, it looks messy more than anything else, but it should work it worked before.

EzzyT

Along with skimming the boiler boiler might need a flushing of sludge along with standard annual service.
The banging noise could be caused by pipe not pitched right & or lack of insulation. @levij06 the best way to reach me is at 2018878856.

BobC

The boiler worked ok before you had the work done so "they" caused the problem. You have a choice, do I get the problem fixed or do I embark on what could be a very long pissing contest,

I don't see a skim port in any of your pictures so I doubt it was skimmed after all that pipe rearranging. Before re-piping anything install a skim port and give it a good skim. Only then will you find what really has to be done with the piping.

If your smart ypu'll just get Ezzy in and let him set it right, that would be a great Christmas gift for the whole family.

Bob

levij06

@neilc - Here's a pic of the mains. Yes I do have wet returns, so apologies. I suppose I don't have a counterflow system. Pardon the noob mistake.

@JUGHNE - also attached a few pics of the relocated pipes. The ones under the stairs is where they added a vent. The other pipes they just moved up to be out of the way.

Thanks for the recommendations, all! Skimming sounds like a good first step.

@EzzyT I will give you a call after Christmas.

neilc

yeah, I don't see counterflow from here,
and if you're calling Ezzy in then you don't need my help,
agreeing with everyone else, Skimming will be key.

EBEBRATT-Ed

I am not seeing much pitch.

109A_5

Hello @levij06,
Is there other access to the vent for future diagnostics and / or replacement ? Or is the game plan to repair the dry wall every time ?

reggi

109A_5 said:

Hello @levij06, Is there other access to the vent for future diagnostics and / or replacement ? Or is the game plan to repair the dry wall every time ?

I was thinking he was lucky the ceiling wasn't finished yet .. 

levij06

ya, we're not planning on finishing the ceiling, and don't mind removing that drywall under the stairs either.

just an update - a different plumber came out (forgot i had already scheduled them before i posted here), and they drained the boiler and cleaned the LWCO (apparently there was a bit of buildup on it). This seems to have solved all of our problems (we're 1 week in at this point) for $, instead of the $ the other contractor wanted to charge me to change the near-boiler piping.

Did a bit more research and learned that if the problem was oil from the new pipes, we still might need to skim if the problem comes back, since draining still allows some of the oil to stick to the sides of the boiler. But for now, so far so good. Appreciate the input from everyone on here.

JIMMYSTEAM

It is good to hear that your problem seems to be solved. I have always had an issue with manufactures showing that one pipe is A-OK when you read Dan's book "The Lost Art" page 48 discusses what can happen inside a boiler when we come out of just one tapping. I also enjoy page 42 "question of velocity" and have taken to heart Mr. Daniel's words of wisdom "not to exceed over 15 feet per second" bringing us back to page 39 "always question existing piping". An EG-55 has a DOE heating capacity of 166k btu page 46 helps make sense of how fast 166k leaving 1 tapping in a 3" riser (0 psig steam having 27 cuft/lb) it is over by about 70%. The contractor may have been trying to make sure that they listened to the dead men and get your system working as they once did slow and quiet. One of the thoughts I have had and expressed to people when they say it worked fine before is it may have worked but it probably could have worked a lot better, like having a car with the tires under inflated, yes it starts, yes you can drive it but what a change in gas mileage, & handling just by adding the proper cold fill pressure. Good luck and I hope that it does stay "fixed" for you.

ethicalpaul

You can believe the manufacturers, they know the velocity of the steam their boilers produce.