Pressuretrols, & Syphons, & Pig's Tails, oh my!

mrmikesimons

Let me start with that I have read Dan's book, seen him speak, listen to his podcast (love it), and have scoured the forums but still(!) I can't get my boiler to cycle on pressure and not solely on temperature.

This all started when I went down into my basement and saw the internal syphon (not to be trusted) pretty much max out. I have seen the numbers be negative when the boiler isn't running and also at 15psi again when the boiler hasn't been firing. But seeing it climb and climb and climb, when I jack up the heat is a bit disconcerting.
***side note some of the radiators upstairs are rather noisy, with each having their own menagerie of sounds.

So I dropped the pressuretrol to .5 with a differential of 1 (as I am told to do), and there was no change in the boilers operation. The thing will just run and run and run until the thermostat setpoint is reached.
***I then read that the pig's tail is the likely culprit, so I had my plumber put on a new brass one (I couldn't remove the steel one) and crossed my fingers, but still no change in performance. (If I trip it manually it shuts down the system. so I know that it was wired correctly)

Next up, I think it must be a faulty (poorly calibrated) pressuretrol, so I ordered a new one and put it on just now. Still no change in performance (I didn't get electrocuted, blasted with steam, or blow up the house--so even though it doesn't work, it feels like a personal victory). For example the Internal syphon started at 10 when I pulled off the old one, and climbed to 28psi before the house hit 75 degrees (all the columns on the radiators were all hot)
***side note, all the radiators are pitched well, and appear to have fully functional thermostatic vents. I also had the main vent replaced when my plumber changed the pig's tail.

With staring at my boiler's piping (and fantasizing about how steam and water move) my next guess is thinking that maybe the pig's tail is installed in an incorrect location. With looking at other photos of steam systems the pig's tail is far above the water line but mine is more or less level with it. I'm thinking of draining off some water so it is clearly below it and see if that solves it? Maybe it is just reading the water pressure and not steam pressure?
Any help and insights would be amazing.

EBEBRATT-Ed

You have a bad gauge. Replace it with a new one. Some install a tee on the pigtail under the pressure control and install a 0-3 or 0-5 psi gauge.

But here's the thing.

Your boiler Does Not need to build pressure to heat the house. Not building pressure in a residential boiler is completely normal.

If the boiler is sized correctly you won't build pressure usually.

Most of the discussions on building pressure are a result of a poorly piped boiler or one that is way over sized.

SteamingatMohawk

Where is the 15psig relief valve?

mrmikesimons

@EBEBRATT-Ed would you believe it to be a useful exercise to adjust all the Vent-Rite #1 vents to the lowest setting, and see if that would cause the pressuretrol to trip? Like I would have a lot more peace of mind knowing that it is communicating someway with the boiler.

mrmikesimons

@SteamingatMohawk it is on the other side of the boiler. I have never tested it when the system is firing... The steam boiler is also tied to an indirect storage tank (not sure if this matters) which also has one. I have tested the one on the DHW.

SteamingatMohawk

I agree the gauge is probably bad.

If the pressure in the system got to 15 psig, the relief valve should have lifted and you would definitely know that.

Depending on what, if any, maintenance has been done on the relief valve, you might want to check it or replace it. It's a small cost to ensure safety functions actually work. Don't economize on one if you do replace it.

mrmikesimons

@SteamingatMohawk okay I just check the relief valve with the system first firing. It very gently spills out steam, would it be useful to check it again after the system has been running for a while and see whether it shoots out with a lot more pressure? Would that be helpful in any determination of whether there is something wacky with the pressuretrol communicating with the boiler?

EBEBRATT-Ed

@mrmikesimons

Your relief valve is ok. Checking it once a year is plenty. Playing with it can cause it to leak.

If you can trip the pressure control manually with the burner running and it shuts the burner down you are ok as long as the pigtail and the gauge glass connections into the boiler are clean,

Clean the pigtail, make sure the opening into the low water cutoff isn't plugged, And blow down the water connection on the low water cutoff occasionally. This will prove the connections are clear

EdTheHeaterMan

So let me get this straight.
You have a perfectly good working boiler that is heating the home properly.
You decide that is not good enough so you have a plumber install a new pigtail and the boiler still heats the house just fine
Then you buy a new pressure control and the boiler still heats the house properly.
Now you are going to get 2 new gauges and install them so that you know that the boiler is working properly... even though the boiler is heating properly.

And the one thing that you should do every year, if not more often, is to operate the relief valve to be sure it is working properly.

I that about right?

I'm guessing that you flush the LWCO at least once a month during the heating season.

mrmikesimons

@EdTheHeaterMan
Hi Ed. Haha thanks for your concern.
A few notes here, we just bought the house this past August-- the original footprint of the house heated by steam is about 2,000 sqft with a small addition on the back that has a separate hydronic boiler. The original distribution system has had at least two radiators pulled off of it, and the variety of noises on the upstairs radiators are annoying enough to wake you up from a comfortable sleep. The previous owner's spent nearly a $1000 in gas this past January for heat.
After having the house completely weatherized (we're still dealing with some single pane windows + storms) our gas bill for November was still close to $300.
I have pitched all the radiators that weren't pitch correctly. Got the mud out of the system (see how good the sight glass looks). Been keep up with flushing it.
The house is comfortable with steam, but the noise and excess cost, and hearing what Dan writes about made me think the pressuretrol wasn't speaking the boiler, especially with seeing the pressure rise and rise and rise on the internal syphon. Like even if it isn't calibrated correctly it was rising when the system past all the limits of the pressuretrol.
Just having the bad internal syphon, doesn't address the cost + noise, so I then thought the pressuretrol (which on this forum has examples of ones that are far from accurate + fail, may be the culprit).
As for operating the pressure relief valve, yes, duh, I should have done it. To be honest, thought it would be rather and violent head of steam that was going to shoot out of it. I saw this at a trade show before and I think that was why...
(https://www.youtube.com/watch?v=ovFq-RPdK1M)

EdTheHeaterMan

Now I know the "rest of the story". (I was a Paul Harvey fan)
So you have experienced high fuel costs and want to be sure the boiler pressure is not at 28 PSI like your gauge indicates.

You can check that with the new gauge, That would have been my first step in the diagnosis process. Get a "Known Good" pressure gauge and attached to the gauge port. A Tee with a right angle pigtail trap can accommodate the 30 PSI gauge required by code and a gauge that measures in Ounces PerSI maybe up to 5 PSI https://www.amazon.com/Ashcroft-14902-5-Dual-Scale-Low-Pressure-Gauge/dp/B00NG3FUXU/ref=sr_1_1_sspa?crid=1BVZD6RRYJRZM&dchild=1&keywords=low+pressure+gauge+0-5+psi&qid=1609890840&sprefix=Low+pressure+gauge,aps,268&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFKVEQ3N09QQ0hMVFomZW5jcnlwdGVkSWQ9QTA4NjA3MzczUzBIU0RZTDVCOFU2JmVuY3J5cHRlZEFkSWQ9QTEwMjg2MzAzMzNJSFVQVDQySThEJndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ== Then figure out if the other parts are operating properly. If the pressure never gets to 12 ounces PerSI then the control won't shut the burner off.

An Ethnicity deleted apprentice carpenter said "This board is too short! And no matter how many times I cut it, It is still too short!"

EBEBRATT-Ed

Jamie Hall

On the fuel costs... are you a newish homeowner, @mrmikesimons ? If so, welcome to reality. Your system seems to be running well, from all the above comments. While you may -- with considerable effort and capital outlay -- improve your fuel use by perhaps 5 percent by working on the heating system, you'll not get farther than that. The best bang for the buck is working on the envelope -- storm windows, fixing leaky windows, draught sealing, insulation, that kind of thing, and from some of you comments I gather that at least some of that has been done as well.

mrmikesimons

@EdTheHeaterMan thanks for that Ed. I work for a company that is quote/unquote "data informed" but I think that I keep forgetting about that in my personal life! I'll send an update once I get the new gages on.

SteamingatMohawk

This may be overly obvious, but I assume your statement about the relief valve "very gently spills out steam" means that you have operated the valve, not that it spills out steam all the time there is any pressure in the system.

One of the downsides of doing maintenance is doing too much and making problems instead of preventing them. I agree with @EBEBRATT-Ed EB

mrmikesimons

@Jamie Hall while a new homeowner, I have been working in residential efficiency for the last 10 years, and have seen a lot of homes and a lot of heating bills pre and post weatherization work. I think part of the reason I was thinking something was "up" with the distribution system is there wasn't as much of a impactful difference between our bills to the previous owner's, after having a significant amount of weatherization work performed. (Maybe when I have a few more months of usage, I'll have a better idea also I don't know if they were keeping the heat at 60 or 72 or somewhere in between) Appreciate the comments, and insights

EdTheHeaterMan

@SteamingatMohawk & @EBEBRATT-Ed have it correct. the tag on a new relief valve saysREADS "operate once a year" Any more than that is asking for premature failure IMHO

Yours Truly,
Mr.Ed

Had to change so no one tells me that "tags can't talk"

mrmikesimons

@SteamingatMohawk thanks for checking, and it turns out that an English degree from a state school isn't doing me much good.
Yes it only spills out when operating the valve.
While I thankfully haven't yet done any harm (I believe) this has all been a great learning experience!

EdTheHeaterMan

@mrmikesimons Is your English degree in Farenheight or Centigrade? (or should I say Celsius to be politically correct?)

Zipper13

Not sure what gas costs for you, but for reference my most recent bill from two days ago is for 160 therms on a 1,550 sf, 1.5 story cape, insulated (but poorly). 100 year old home with 10 moderately drafty original windows still remaining (these have storm windows, and the others have been replaced by previous owners).
Since we've been working from home we've kept it at 68. Though last year we ran a three degree setback at night and during working hours at the office. I'm no mathimagician, but taking a look at the heating degree days and billing records from last year, I'm not sure the setback saved us all too much money but this year for sure feels more comfortable in the house just running it steady!

I'm not sure if it's been established if this is a 1 pipe or 2 pipe system we're talking about, but it might be relevant. I was really proud for a while since installing a low pressure gauge I saw that we never got higher than 3oz of pressure on our two pipe steam system! But this year I realized that all of the traps are failed open, so there's nothing to build pressure against. turns out that's likely why my boiler never cycles on pressure. I suspect that adds up to wasted money for me...and maybe you too?