60+ year old two-pipe steam boiler

DML

Hi there,

As the subject indicates, I have a very old steam boiler. Moved into this house nearly 4 years ago and it’s mostly worked fine, though had some issues consistently over the years. 

Our current issue is that the water in the sight glass is surging up and down … a lot. It means the system is constantly turning on and off, never heating well, and costing me an arm and a leg in gas costs. (This system costs a boat load in gas costs already, so it’s now past the point of ridiculous). Also, many of the radiators now make a weird noise when the boiler is running - it sort of sounds like water is running through them and “cranking,” even though of course no water is. 

There is a lot more data I can share, but not sure what will be relevant. Brought in a plumber who says he knows steam well and he immediately pushed me to just replace - said fixing it wouldn’t be financially worth it. He may be right, but I’m not yet totally convinced. 

I took a video of the surging here: https://streamable.com/3k2zyi

Any and all help would be appreciated. 

DML

I should add - the surging issue started a day or two after the plumber added a bottle of boiler cleaner that he said would eat at any rust. Could this have caused the issue?

I’m a novice on all of this, so direction as to fixing, if possible, would be so appreciated. Happy to post additional pictures or videos if helpful - just let me know what you need to see. 

WMno57

DML said:

Happy to post additional pictures or videos if helpful - just let me know what you need to see

Yes, please post pictures. They don't need to be videos.
Please stand back from the boiler so your picture includes the near boiler piping.
Please post the pictures here on this site. Easiest way is to cut and paste. Ctrl-C and Ctrl_V.

Jamie Hall

"I should add - the surging issue started a day or two after the plumber added a bottle of boiler cleaner that he said would eat at any rust. Could this have caused the issue?"

It surely could have. In fact, it probably did. Best course now is to turn the boiler off, let it cool, drain it out completely, fill it about half way, drain it again, and then fill it with nice clean water and restart it.

Sometimes a very limited amount of a pH stabilizer and corrosion inhibitor is warranted -- but only rarely, and in very small doses. indiscriminate adding of boiler cleaner or even supposed water conditioners never works out well.

DML

Here are two. Let me know if you need more, and of what specifically. 

Jamie Hall

Have you drained it and refilled it yet? Just do it.

DML

Jamie Hall said:

"I should add - the surging issue started a day or two after the plumber added a bottle of boiler cleaner that he said would eat at any rust. Could this have caused the issue?" It surely could have. In fact, it probably did. Best course now is to turn the boiler off, let it cool, drain it out completely, fill it about half way, drain it again, and then fill it with nice clean water and restart it. Sometimes a very limited amount of a pH stabilizer and corrosion inhibitor is warranted -- but only rarely, and in very small doses. indiscriminate adding of boiler cleaner or even supposed water conditioners never works out well.

Helpful, thanks. This was a few weeks ago already and it has been running on and off since. I’ve tried to rely on my mini splits instead of the boiler given the issue, but it’s been so cold here I’ve needed the boiler at times, too. 

Does this change your recommendation at all?

Also, and apologies for the truly dumb question — other than draining the boiler like I do every week, but leaving that valve open until nothing else comes out — is there something else I must do in order to “drain it out completely?”

I’ve read about skimming - is this something I need to worry about? (I’ve read directions on here but have no idea how to follow them. True novice!)

STEAM DOCTOR

Drain from the bottom, not the LWCO. Might take more than a few times to get that chemical and the junk out.

Jamie Hall

STEAM DOCTOR said:

Drain from the bottom, not the LWCO. Might take more than a few times to get that chemical and the junk out.

This. There must be a drain valve down at the very bottom. That's the one to use. You need to get all that chemical and junk out, as @STEAM DOCTOR said.

DML

Is there an indication that it’s all out? I’ve done it twice now and on the second round the water came out perfectly clear. 

neilc

we should also see a pressure gage there somewhere,
what do you see on it? picture?
pressure when firing and the water drops out?
and a closeup on the Ptrol,
have you or your guy checked that pigtail?
it needs to be free breathing all the way back into the boiler / LWCO

DML

The pressure gauge on this machine hasn’t worked since I moved in. Attaching a picture. 

What is a Ptrol? Pigtail? (I’m a novice!)

after filling and draining a few times, I currently have the system running. About 50 minutes in, and so far no major surging and the boiler has run consistently without turning off. 

neilc

OK, so, bad pressure gage,

on top of your LWCO is that looped pipe, (it looks like a pig's tail),
the Ptrol is the pressure regulating / safety device on top of the pigtail,
I haven't seen that one before,
a close up picture please,
and a second one with the cover off if your comfortable, (shut off the service switch)

consider adding a tee under the Ptrol and adding a second gage there,
low pressure, 0-3, 0-5, and add a ball valve to isolate the 2nd gage,

if it's running now, don't fix it, right?
except you should know the Ptrol is working for you,
and the LWCO also,
the bucket says you've been doing blowdowns, correct?
and do them while it's firing, it needs to shut the burner off as the water drops out,

there's a website store here which sells books, great reads for novice and pro alike,
We got steam is easy reading, and written for 1st timers,

https://www.heatinghelp.com/store/detail/we-got-steam-heat-a-homeowners-guide-to-peaceful-coexistence

BobC

I would look at two things. First would be the pressuretrol which is usually a grey box sitting on top of s curly pigtail pipe. That box wants to be set low (1 to 2 PSI on the main and 0ne on the little white wheel inside the box) Those can get gunked up and then the pressure gets to high because that pressuretrol has no idea where the boiler is sitting pressure wise. You have to unwire the pressuretrol and spin it off that curly pipe - MAKE SURE POWER IS OFF. Make sure the pipe is clear and look at the base of the pressuretrol (inside brass fitting) and make sure the little hole is clear. Once you know everything is good, put it back together and wire it back up. Next I would grain the boiler completely a couple of times and fill it back up to the normal level. Steam does not like dirty water which can cause it to surge.

This picture shows my old boiler with a vaporstat (a more sensitive version of a pressuretrol) sitting on a pigtail, it also shows the 0-3 PSI gauge I added near the vaporstat.




Turn the boiler on and see if it acts any better. That old gauge may not be working right, you might want to add another 3 or 5PSI gauge up beside the pressuretrol so you know what pressure your running at. If cleaning the water helps but the boiler starts to misbehave in a few days it means there is oil in the water and the boiler has to be skimmed. Thats simple if the boiler has a skim p[ort not so simple if it does not.

Bob

EBEBRATT-Ed

Your probably going to have to skim to get the junk out of the boiler. The plumber never should have put that in. Where are you located? Check find a contractor on this site and post your location someone may know someone in your area that knows steam.

WMno57

I like your boiler.
I don't see a power switch on the boiler or 120v wiring going to it.
You may have a boiler that can heat your home without grid electricity, backup generator, or solar panels. As long as the gas stays on, you have heat. This is called a PowerPile gas valve. Heat from the pilot light makes a small amount of electricity which is used by the thermostat.
Example of PowerPile valve, not necessarly an identical swap for yours.
https://www.supplyhouse.com/Resideo-VS820A1047-Standard-PowerPile-Millivolt-Combination-Gas-Valve-1-2-NPT-x-3-4-NPT
Although parts are still sold, these boilers are no longer sold.
Be sure and invite the green know it alls over to your house during the next power outage.
Your boiler will blow their minds.

Jamie Hall

I'm glad you can report you have it working more properly again. Nothing like clean water, eh? The other comments on the pressuretrol and pressure gauge are somewhat less urgent -- although they probably do need attention. But if the poor old thing is working smoothly enough and without indigestion, you can -- and should -- take your time to learn as much as you can about the system and find someone who really does know what they are doing to help you with it.

DML

Thanks to all for this helpful information. Truly amazing how much goes into these machines!

After draining a few times, the boiler ran for about an hour and reached the thermostat’s set temp without issue. The water in the sight glass was brownish about 30 min after it stopped running. I drained a bunch again and added fresh water to “top it off.” A lot of what came out was brown. I assume more gunk in the boiler? Or maybe coming back from the pipes? Either way - haven’t run the system again yet. I’m hopeful this was it — a really easy fix. But it’s an old boiler that I doubt was well maintained over its life based on other things in this house that we’ve discovered, so probably won’t be fixed on this alone. 

As for pressure — is it unsafe not to have a working pressure gauge? No plumber or hvac company has ever commented on it to me, and I’ve had a few come by over the four years I’ve owned this house. 

I do blowdowns weekly to get gunk out, sometimes with the boiler running and sometimes off. The fire turns off when I open the valve to blowdown. It turns back on after I close the valve and a few seconds later hear a little “click click.” The LWCO absolutely works, that I know, as well. What does the ptrol actually do? Could I know it’s working without taking the cover off?

I hope I don’t have to skim, as I’m not sure I’d have any idea how to do it, even with videos I’ve watched assisting. Where would I find if there is the proper hole for that?

I'm located in Westchester, NY. Bummed the plumber put the chemicals in, now that I know what they caused…

I do believe the boiler can run without power. There’s no C wire to the thermostat, that I know.

Based on the googling I’ve done with the info from the below picture, I’m estimating this boiler is from the early 60s. But I welcome a closer estimate from those of you who know what you’re talking about!

delcrossv

Having a working pressure relief valve is the necessity. A low pressure gauge is a good diagnostic tool. 

With a boiler that old, you'll always get some rusty water from the bottom tap.

DML

delcrossv said:

Having a working pressure relief valve is the necessity. A low pressure gauge is a good diagnostic tool. 

I presume I have a working pressure relief valve. Is it visible from the outside? If the boiler is functioning, any reason to suspect I have an issue with that?

WMno57

DML said:

Is it visible from the outside?

Coming out the top of the boiler cabinet. Left Rear corner, first picture.
That boiler is worth taking care of. Would you be interested in having a steam knowledgeable contractor look it over every Fall?
@Mad Dog_2 Do you service the Westchester area?