Noticed some oddities with my 2 Boilers

jcullina · January 14

I have a 2-family house with two Burnham steam boilers and have recently started paying attention to them because I had a bad tuneup experience so I finally read “You Got Steam Heat” and noticed that the two guys sent to do my recent tuneups either made mistakes or overlooked apparent mistakes made by others before them. The pigtails on both systems are not perpendicular to the boiler, as recommended. I placed a level on each and - lo and behold - they are not level. (Plumber said that’s not a problem!) The pressurtrol settings on each are also funky. Unit 1 is set at 7.5

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psi but it is ironically always running at 0 psi. From what i see, Unit 2 usually runs at 2.5 psi and gets as high as 5 psi at times (I’ve checked patterns a bit and this is usually when the tenant’s thermostat settings ask it to jump a few degrees after being down lower at night or during the workday). The 5 psi has me worried. Of course, the guys say they did not check the high pressure valve (said it might not have closed again if they’d tried to). Unit 2 has the DIFF set higher than the MAIN. Isn’t that backwards from the norm? I’m like, why the heck did nobody ever mention these strange things my furnaces are doing? I lived in the house until 5 yrs ago, and the system has functioned but i want to maximize it and focus on which components need upgrading, and in what

And why is there only one main vent on the return but none where the steam travels out and upwards?

EdTheHeaterMan · January 14

First of all… what problems are you actually experiencing? Just because you now know where the pressure settings are on the control does not make it operate differently.

Are any of the radiators getting too hot or not hot enough? Is there any banging or noise that you need to address? Are you experiencing unbalanced heating from one area to another area served by the same boiler? And they are called boilers, not furnaces. A furnace heats air and your boilers heat water.

So to cover one point that many people misunderstand about limit controls. Those controls LIMIT the maximum temperature or pressure or humidity or water level. The don't make the appliance get there. They make the appliance stop if it gets there. On your steam boiler that is set at 7.5 and operates at zero. that may be that your boiler is the perfect size for the connected radiation. It puts out just enough heat to make the steam get to all the radiators without ever going above a few ounces of pressure. That is a good thing.

If the pressure always stays below the 7.5 setting and you are getting heat then I would not worry about the pressure gauge reading of zero. If you need to know you need to add a second gauge that measures pressure in ounces per sq in. The zero to 30 PSI gauge is like using the odometer on a car to build a home. The measurement increments are way to large to make precise measurements. You need a ruler that measures down to the fraction of an inch to build a home.

The zero to 30 PSI gauge is a code requirement, not something you actually use to see what the boiler is doing. A second gauge that measures from zero to 2 PSI in increments of ounces is what you need to see what is going inside that boiler if you really need to know. 2 PSI gauge 0 to 32 ounces/SI

patrykrebisz · January 14

Here is a video i've made that shows why you don't want any pressure (or very little pressure) in your steam heating system:

https://www.youtube.com/watch?v=lRzrCievDUI

jcullina · January 14

Hi Ed, After the tuneups I noticed the water was more than 3/4 up on unit 2 (the one that hits 5 psi at times), so i let some water out but v the water actually rose in the tube when i did that. That puzzled me. At that point it was up above the high sharpie mark you see (i’ve texted them to ask why they put the mark up there but have not heard back). So when it went higher, it was near the very top of the tube. Checked the next day and it was a bit lower, and lower again the next day. Delayed response to the water I’d taken out? If so, why the delay?
I began doubting the sight tube, which is a spot i don’t want to be in. So I’m visiting to look at it every day now.
Or i thought maybe a leak would explain how the water level resettled to such a lower point over the few days i watched it do that.
There are no problems with any radiators heating up and no spitting vents or leasing radiators. The water has settled more or less around the halfway mark for now (see the tape in the pic, which some other plumber put on there in some long ago era ), so i feel better but i know the system needs some attention as it is 22 (?) yrs old and the guys i had in just did a basic cleaning. (And left the pigtails on sideways..).

They said it works as well as it should “for an old system like that.” Ugh. I want it to last and they want me to chuck it out the window.

How much should the water level vary (the top to bottom differential) when looking at the sight glass?

jcullina · January 14

Hi Patrick,

I love your drawings. I wish I’d happened upon such great visualizations a lot earlier in my boiler-owning lifetime. I grew up with steam and have had it in practically every place I’ve ever lived but never thought about it before!

So is the 2.5 - 5 psi level on unit 2 because there is no main vent i can see except on the return? Where exactly is the “end of the main” if we were to have one installed? I see all pipes lead up into the basement ceiling and upwards with no vents on any of them.

And is it common for a plumber to set the DIFF higher than the main? I understand it should be set at around 1.5 since the MAIN is at 2. (The psi setting for the DIFF is on the far left, right?). (I know these aren’t as sensitive as vaporstats, but..)

The other one is set at 7 psi which is weird. Glad it runs at 0 but am skeptical that’s accurate as both systems have the same limitations. Worth noting we have no insulation in most of the pipes and no main vent on that side either.

Can i have the pressurtrols and sight tubes tested for accuracy? One tenant is now worried and that’s why I’m learning all i can. Maybe i need a ‘diagnostic checkup’ of sorts to keep this system alive and happy? On top of The $400 we just paid for the tuneups…
Joanne

patrykrebisz · January 14

your pressureyrol should be set to 2psi on main (this means ptrol will cut power to burner when it reaches 2psi) and 1.5psi on differential (this means pressure will drop 1.5psi before power is restored). This is IF your pressuretrol is working correctly. yours have mercury inside so maybe they are more precise. Those with brown switch are notoriously badly set from the factory and often NEVER work. the easies way to check is to add T between pteol and pigtail and mount 0-5psi gauge.

jcullina · January 14

Patrick, that’s what I thought. I’m wondering what the system itself makes of the fact that it is set with the DIFF above the MAIN so that it is being asked to only cut in at a negative psi(!). Odd way to set it, and i have no idea who did it or why. Most recent guys just said they left everything as they’d found it.
I’m afraid to reset this myself, though i know it only requires a screwdriver to do so, because i don’t know why it was set that way. Ditto for the other system that is set for 7 psi.

Could the crazy DIFF settings on the unit that gets up to 5 psi at times be responsible for the higher pressure readings? Or is it more likely that the lack of insulation and of a main vent in the basement or some other issue causes it to stay between 2-5 psi at all times?

patrykrebisz · January 14

pressuretrol are stupidly simple devices. inside you just have 2 springs.

it seems 1 of your ptrols is set up 2 main and 2 diff. this is ideal. (translate: shut off when pressure reaches 2psi and thrn on when all pressure disapears).

on another ptrol it looks like main is set at 7 and diff at 3. just screw both screws so main is 2 and diff is 1.5. and if u have issues you can always gi back to ref photo you took.

(i have a bunch if new videos specifically related to ptrols coming out after the weekend)

jcullina · January 14

thanks, patrick. The DIFF is set above 2 psi. On my pressure the psi scale is to the far left and the other scale under the DIFF side is for kg/cm2. On that scale it is just under .2, which is about 2.5(?) psi.
Sounds like the pressurtrol is a really basic device, but what happens when the DIFF is higher that the MAIN like this?
I assume i should also add a main vent or two in the basement for each system, but especially the second floor system? It appears there are two vents heading from the system toward either end of the house, with one main feeding five radiators, and the other feeding two small ones.

Clearance is tight, though. Are the main vents always installed vertically on a pipe?

patrykrebisz · 1:00AM

generally, each main needs a main vent at the end of the pipe.

yes, the are all installed with opening pointing up.

TonKa · 1:17AM

Older, mercury type pressuretrols must be level if you want the settings on them to actually mean something when compared to a working, low pressure gauge.

Noticed some oddities with my 2 Boilers

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