Steam Pipe Insulation

denkelly

As my first post, I am going to open myself up to ridicule and ask a true noob question. Thing is, I know I need to insulate the pipes, but I guess I need that little bit of convincing to get me over the hump to spend the money and get covered in fiberglass....

House was built in 1938, attached house in Queens NY. I have owned the house since 2015. The boiler is a Weil-Mclean that is roughly 12 years old at this point. I flush it annually.

Regarding the pipes, one set of pipes goes almost straight up from the boiler to the kitchen and the second floor. The other runs the length of the house, about 35 feet to feed the living room, and second floor. The lack of insulation keeps the finished basement toasty.

I have changed most of the air valves as there was no heat to the front of the house when I got here. The system works well and is nicely balanced. I do hear the main valve at the front of the house does not seem to be closing, so that needs to be changed and I do have to add water about 2x's a week now. This is new, but I am reticent to change it until the winter is over for fear I will break something and create an emergency plumbing need that I cannot afford.

What am I doing wrong?

Jamie Hall

I dare say that the uninsulated pipes keep the basement warm. Unhappily, that also means that you are not getting the heat you are paying for in the rest of the house -- neither as much, not as fast. Applying fiberglas insulation to the pipes is neither hard nor messy. The stuff comes in preshaped sections, sized to the pipe, and simply gets snapped around the pipe and taped shut. You want 1 inch thickness. There are a number of sources for it.

As to the water loss. That is generally regarded as excessive, and I'd go looking for vents which aren't closing tightly, or valves which are leaking a little around the stems, or if you have wet returns (basement floor level) if any of them show signs of leaking.

Hap_Hazzard

Is your boiler atmospheric? If it is, a lot of that warm, toasty air is going up your chimney. Even if you have a flue vent, the boiler is using the air from your basement to burn the fuel while it's running, and if you don't, that warm air is rising up the chimney 24/7 and pulling cold air into your house through every leaky door, window and fireplace to replace it.

Before I insulated my pipes, my basement was so warm I used to think about putting sand on the floor and having beach parties down there. My wife wouldn't let that happen, so I figured I might as well insulate those pipes. Now the basement is still the warmest floor in the house, but it's not tropical anymore. Your mileage may vary, but you can always just keep adding insulation until its just reasonably warm.

Hap_Hazzard

Regarding your main vent, sometimes it's hard to hear them close, especially the bimetal strip variety. I have to hold a lit match next to mine to see if there's air rushing out. If you see the boiler pressure start to rise at about the time your radiators start getting hot, that means the vents are all shut. You can't build pressure in an open system.

If the vent isn't closing it could be related to the lack of insulation. Uninsulated pipes add to the radiant load. They use up steam. If you're using up all the steam before it reaches the vent, the vent won't close. If it's just passing air or panting, that's what it's supposed to do. You can only blame the vent if it's leaking steam, and in that case, it may account for the water loss.

The loss of water could have many causes: bad vents, leaky returns or a leak in the boiler itself. Weil McLain boilers use elastomeric seals between the sections, and they can fail. Sometimes this can be caused by bad piping, but sometimes it just happens with age. If the boiler is leaking internally, you'll usually notice a big white cloud coming out of your chimney.

denkelly

Thanks for the info everyone.

I will look for puffy white clouds out my chimney, but I also just changed the main valve at the front of the house and no more hissing. Fingers crossed.

In the process of this, now I am noticing that my pressure is running between 3 and 4 psi. I didn't watch the valve the whole time, but the burners stays on until 4 psi and kicks off and then it drops to 3 and the flame kicks on again. The Pressuretrol is set foe the lowest possible cut in and the cut out wheel is at 1.

I've been reading about how thew Pressuretrol kinda stinks, and wonder if it's time to get a vapor stat? If I have a Honeywell 404A Pressuretrol, what vaporstat so I need?

Money is also tight, and I've also read about calibrating the 404A. See the picture, is that the set screw that you can turn to try to get this thing working better? I don't understand cut out and cut in, and that screw is supposed to calibrate cut out I think.

ethicalpaul

Can we see a pic of the front setting?

Cut out is the pressure at which the ptroll switch opens to kill the burner.

Then Cut-in is the psi at which the switch closes again to allow the burner to fire again.

Your PTroll is “additive”. The cut-in is on the front and then you add the value on the wheel inside to get the cut-out. Set the front setting as low as it goes without disconnecting the linkage inside.

Your white wheel should be 1. I can’t quite tell cuz you drew your arrow over it.

denkelly

Here is a pic of the front setting. The wheel is on 1.

when you say set the front setting as low as it can go without disconnecting the linkage, that means keep turning even after the indicator is already at .5?

ethicalpaul

Where you have it is about as low as it goes.

What I meant is pretty much what I said: if you keep turning the screw after the indicator bottoms out, you will unscrew the spring linkage inside and it’s fiddly to reattach so you don’t want that. But you do want it as low as it will go generally.

I’m not a fan of messing with that internal tiny setscrew.

Your pigtail line to the pressuretrol may be blocked and in need of cleaning. The ptroll you have there is usually not amazingly accurate, but it’s usually more accurate than you describe. But it can only act on the pressure it “sees” so check the lines leading to it.

Although if you are nervous of things going wrong I’ll tell you that my pigtail’s fitting broke off from rust when I first removed it and I had to scramble to Home Depot to restore things. It helps to mess with stuff on a lazy Saturday after a successful call for heat warms the house

Do you believe your gauge? Is it a 0-30psi? Your ptroll may be more accurate than the gauge.

It is very educational to watch the gauge through an entire heating call. For example: is the boiler shutting down on pressure then starting up multiple times to satisfy the thermostat? How long does it take to build up pressure? Etc

Hap_Hazzard

If you do see those puffy white clouds coming out your chimney, you're definitely going to want to keep the pressure as low as you can get it and still heat your house. The higher the pressure gets, the more steam you're going to force through the crack, because it's the only way steam can escape when the vents are all closed.

denkelly

I'm a bit reticent to mess with that screw too... if something breaks I have to scramble to get the heat working. That would be less fun than a high heating bill....

I have no idea if the gauge is accurate or not. I've read a bunch of places that a lower psi gauge is better, but is a $30 5psi amazon gauge any more accurate than what I have? That's an answer I don't have. You have any experience with that?

I will look into checking the pigtail. Thanks.

I will watch gauge through a cycle. I can tell you that it does shut down on pressure and cycle multiple times until the house warms to the set temperature.

ethicalpaul

> @denkelly said:
> I've read a bunch of places that a lower psi gauge is better, but is a $30 5psi amazon gauge any more accurate than what I have? That's an answer I don't have. You have any experience with that?

Yes, I do. Yes, it is almost certainly more accurate than a 0-30 gauge of unknown age and condition.

> I will watch gauge through a cycle. I can tell you that it does shut down on pressure and cycle multiple times until the house warms to the set temperature.

OK, that’s good to know. But I reread your thread. Is your main vent still not closing? You really should fix that.

But if your system is shutting down even with a leaking main vent then that doesn’t speak well to its size being appropriate. And if you insulate your mains it will make your EDR even less, amplifying the possible size issue

denkelly

Regards the gauge, my gauge is a back mount. I assume I can't mount a bottom mount sideways, can I? I need to get pipes to make the gauge be upright?

you say it's good to know that it shuts down and cycles, so that's how it's supposed to work?

I replaced both main vents yesterday. That issue is resolved.

I think this boiler was installed after the asbestos abatement and maybe they sized it for the exposed pipe? I guess I have to do some math to try to figure that out, huh?

Hap_Hazzard

Leave the original gauge where it is. A 30 psi gauge is required. (God knows why.) Mount the low pressure gauge on a tee off of the pigtail so it reads the same pressure your pressuretrol sees.

ethicalpaul

denkelly said:

Regards the gauge, my gauge is a back mount. I assume I can't mount a bottom mount sideways, can I? I need to get pipes to make the gauge be upright?

A lot of people will leave that one in place and put the low pressure gauge on a Tee with their pressturetroll

> you say it's good to know that it shuts down and cycles, so that's how it's supposed to work?

No, but it's very common. The correctly-sized system will create steam at a rate that is more or less matched with the radiators' ability to condense steam (expressed in EDR). The PressureTroll is really meant as a safety control they tell me, it's not supposed to be activating generally. But again, lots of them do.

> I replaced both main vents yesterday. That issue is resolved.

Nice.

> I think this boiler was installed after the asbestos abatement and maybe they sized it for the exposed pipe? I guess I have to do some math to try to figure that out, huh?

Don't give them that much credit. In the old days they reportedly made the boilers large because of the Spanish Flu (google it LOL). Then over the decades as the boiler was replaced, it was common for the guy to say "that size worked OK but it won't hurt to go to the next bigger one" and that may have happened a few times. It's all too uncommon for contractors to actually size the radiators. But the contractors who hang out on this forum are the happy exception.

Also in the 70s the homeowner might have installed better windows and maybe even filled the voids in his walls with insulation (!!!) which further reduced the BTU needs of the living space. Now faced with blazing radiators, they might have removed some, worsening the oversized state.

For you, just measure your radiators and add up the EDR and match that against "Net EDR" on the boiler to see how they compare. Don't worry about the mains too much. Insulate them sometime, don't add EDR for them, Net EDR is already padded for them.

denkelly

Thanks to both of you for your input on this.

My gauge is already on a T with the PTrol. I assume I can come off that T and add both gauges to that? Is that too rigged?

I hear you about the oversizing possibilities. Sounds entirely too plausible. Just FYI, the house is attached on both sides with these old steel fin type radiators No insulation, all brick with original leaded front windows with an inner storm window. New windows will be a big expense.

I guess I can just estimate those fins to be the same EDR as baseboard radiators?

So to sum this all up:
1) No rush to insulate the main pipes, but do the EDR calc to see if (or rather how much) oversized the boiler is)
2) put on the low pressure gauge
3) if the pressure is actually 3 to 4 psi then I should take some action to remedy that?

ethicalpaul

"Too rigged"? What's that LOL

But seriously, post a picture of the front of your boiler and we'll see how rigged you can go.

That radiator makes me wonder. I was assuming you had single pipe but that's my fault. I wouldn't expect to see that vent on it. It looks like a new addition?

I like your summary

denkelly

That's not a pic from my house, but I have the same type of radiator. Mine is single pipe.

I'll send a pic when I get home, but the boiler is an EG-50 Weil, and if I did this correctlyhttps://weil-mclain.com/sites/default/files/field-file/Weil-McLain_BoilerReplacementGuide_WM1905-web.pdf then my heat loss is 67,000 and the gross output of that boiler is WAY OVERSIZED.... Holy smokes. What do I do now?

Hap_Hazzard

What you've got there is a fin-tube convector. They pack a lot of EDR into a small package. They heat well, but they don't stay hot for long when the steam shuts down, and they don't work very well with one-pipe steam. Because of the high EDR, they consume a lot of steam and return a lot of condensate, and the supply fittings are often too small to allow for that.

ethicalpaul

It’s not necessarily too oversized. You have to compare it to the EDR of your radiators, the BTU needs of the house aren’t directly related. Don’t panic anyway, lots of systems are oversized.

denkelly

I'll keep trying to figure out the BTU output of my system, but that seems to be an exercise for a man with more free time than I have! LOL. I'll have to find a reliable EDR chart for the fin tube. I do get some noise in the living room radiator, which has the fin tubes stacked, but only on initial system heating. Once it's all up to temp it stops. No idea how to remedy that. I have everything pitched. I set that up when I had someone replaced the leaky valve on that radiator.

In other news.... I watched my system cycle (it wasn't first run of the day, had been sitting about 90 minutes since last run). I'm going out on a limb and saying my pigtail is not clogged and my gauge is accurate enough. Here's why:

Minutes. Description
0:00 Call for heat and damper starts opening
5:30 Main rear riser(?) vent closes and is at temp
9:00 Front main vent closes and is at temp (35 foot run)
10:00 Start seeing pressure in system ~1.5 psi (see pic)
All radiators in house are warm.
12:30 Boiler hits 4 psi and flame turns off
13:45 Boiler cycles back on (cycle take 1.5 minutes)

picture of gauge at 10 minutes


picture of boiler


Pigtail Pictures

ethicalpaul

First, that's a great timeline you made!! You are going to know so much about your system! One thing you left off-- how many cycles did it take before the thermostat was satisfied, and had you moved the thermostat or did you just catch a normal call for heat?

It does seem from your timeline that pressure is rising and cycling, regardless of what that pressure is. If it were me (and it was a year ago) I would still get a 0-5 gauge to make sure. You do want to try to get the cut-out to 1.5 or 2.

Second, you have bad near-boiler-piping. On your "rear" riser, do you imagine how steam and water droplets are barreling along from the supply horizontally to the rear? Then due to the shape of that rear Tee, both will get carried up to your rear riser and you will get a lot of wet steam or even actual water in your rear main. This isn't great.

You will want to do everything you can to make sure the steam production is as dry as possible in the boiler (clean water, not too much chemical additive, no oils on the water) to try to minimize the water getting carried into that rear main.

denkelly

Thanks. I had raised the temp on the thermostat 1 degree to call for heat. I did not count how many cycles, but it was 10-15 on a guess.... I'll check that later after the temp comes down in the house.

From what I am gathering, I need to get the low pressure gauge, BUT I also need a new way to control the pressure, which means a vaporstat, no? Seems like I should see less burn time on the boiler and some savings if I can manage that pressure better (which will help me keep the steam dryer and mitigate my bad piping issue as well)? Is that correct? I would install that with the low pressure gauge off the existing pig tail.


Also that rear main (the one to the left in the photo) leads to the front of the house where I do get water hammer in my first radiator, so that may be the cause of that.... I assume this wet steam happens even at lower pressures?

And how do you keep the water clean? I flushed the system completely at the beginning of the heating season and there are currently no chemicals in at at all. Any suggestions there?

pecmsg

Remember Code requires a 0-30# gauge as well.
Install a T and valve for the 0-3# gauge

ethicalpaul

Yes, if you determine that your pressure is going up to 4psi then you will want to either get your ptroll working or replace it. You don't really need a vapor stat IMO--a working ptroll should be fine. Others might chime in about that. This will reduce the time that your boiler is needlessly (and in fact harmfully!) raising its pressure.

It may result in even more cycles overall, but I consider that the lesser evil. Once you size your radiators' EDR and compare it to your boiler's EDR we can better understand why it's cycling. I think you have stated this before, but both mains have working main venting, correct?

Yes, water getting thrown into a main can definitely cause hammer and other problems like heat not getting to some rads, and spitting rad vents. The wet steam can happen even more at low pressures since the steam is rushing with little resistance to the lower pressure areas. Once the system is all pressured up with most/all vents closed, the steam velocity seems like it would slow.

That's good about the water. The only thing left to check would be the presence of any oil floating on it. There may not be any but if there is, then draining the boiler doesn't help because as the water drains the oil gets deposited on the sides of the boiler. The way to clean the floating oils is by "skimming". If you do some searching you can see what that's all about.

(I do like minimal water additives just to get the PH up to reduce oxidation, but too much causes foam or rough boiling)

denkelly

pecmsg said:

Remember Code requires a 0-30# gauge as well.
Install a T and valve for the 0-3# gauge

Thanks, and yes, my Picasso drawing keeps the 30psi gauge. There is a T behind it that I would build the top off of that holds the other 3

denkelly

ethicalpaul said:

Yes, if you determine that your pressure is going up to 4psi then you will want to either get your ptroll working or replace it.

but both mains have working main venting, correct?

The way to clean the floating oils is by "skimming".

(I do like minimal water additives just to get the PH up to reduce oxidation, but too much causes foam or rough boiling)

Other than fiddling with that set screw, how can I get my Ptrol working? Also your experience is that a working Ptrol will give me the pressures I seek?

Yes, both main vents are brand new. I tested them with a lighter this morning, pretty cool how fast the air vents!

so I don't seem to have any skimming piping.... I would need to have an outlet near the water line on the glass, correct?

Hap_Hazzard

denkelly said:

Other than fiddling with that set screw, how can I get my Ptrol working?

Other than making sure the pigtail isn't blocked, there's not much you can do. If it's shutting off the burners, but not at the right pressure, you need to re-calibrate it, i.e. fiddle with the set-screw. If, on the other hand, it's "seeing" pressure but not interrupting the burners no matter how high the pressure gets, the microswitch could be bad or there could be a mechanical issue. Try pushing up on the right side of the rocker and see if the switch clicks. Then try it with the burners on. If it clicks but the burners stay on, or if it doesn't click at all, the switch is bad.

denkelly said:

Also your experience is that a working Ptrol will give me the pressures I seek?

If the pressure you seek is 1.5 psi cut-out, .5 psi cut-in or greater, then yes.

ethicalpaul

I probably shouldn't answer about how to get a Ptroll working, but yes a working one should cut-in at the pressure on the front and cut-out at that pressure plus the internal dial indication. And lots of them do.

Vaporstats seem to be more highly regarded, but there was a batch of those that went out apparently with pressure problems too, so it's hard to point at them without question too. Regarding your drawing, you would probably replaced the possibly faulty Ptroll with its replacement vstat or Ptroll.

The skimming port is typically at or a little above the top of the sight glass.

Page 10 of the pdf below shows your ports. The skim ports are labelled "S"

https://www.weil-mclain.com/sites/default/files/field-file/eg-peg-egh-series-4-manual_1.pdf

denkelly

ethicalpaul said:

I probably shouldn't answer about how to get a Ptroll working,

Aw come on! Please! I won't do anything stupid. If my heat stops working my wife will kill me. Also I have a plumbing supply 3 minutes from my house, if I break it I can run over there and buy a new one.

Thanks for the info on the skimming, I'll look for a valve I can fit to that to get that done.

Thanks to everyone for your info. This forum is fantastic.

ethicalpaul

The set screw method at least is documented on this forum in several threads. I would have a new low psi gauge on hand before I did any work on the ptroll. No sense working on it if you can't then verify its behavior

denkelly

I just ordered a 3lb gauge. I should get to installing that next week and then I'll let you all know how it goes.

Thanks!

denkelly

On another note, I just ran another 1 degree increase cycle. My earlier estimates were off by a bit.

Cycles are 2 minutes on until 4 psi and 2 minutes off to 3 psi and repeat.

Total time to heat was 26 minutes and after the initial burn the boiler cycled on and off 5 times before satisfying the thermostat.

Don't know if this is good or bad....

ethicalpaul

It’s not optimal but it’s not world ending. I look forward to seeing how it does with a 1.5 cutout.

And also what your radiated EDR is

BobC

I saved the procedure to calibrate pressuretrols but I did not save the name of the gent that developed the procedure. You may have to apply a little heat to get that hex screw to turn.

Bob


Pressuretrol Calibration:

If you see the pressure on the low pressure gauge go much over 1.5 to 2 lbs follow this procedure to re-calibrate the Pressuretrol:

Inside the Pressuretrol, right below the micro switch, there is a pivot arm. At the end of that arm you will see a screw pin that is activated by the diaphragm at the bottom of the Pressuretrol. If you look very carefully at that screw pin, you will see it actually has a tiny (I mean tiny) hex head on it. It takes a .050 hex wrench and you can turn it clockwise (Towards the bottom of the Pressuretrol to decrease the Cut-out pressure or counter clockwise to increase the cut-out pressure (which none of us want to do but who knows, your Pressuretrol may be really screwed up!). Turn the power to the unit off first. You may find the first attempt to turn that screw a little bit stubborn (relatively speaking) because it has some Locktite on it but it does turn. Don't turn too much, a tiny fraction of a turn goes a long way towards getting it adjusted where you want it (maybe 1/32 inch turn to start with) . You may need to play with it to get it exactly where you want cut out to be.

denkelly

Radiated EDR:

I'm having trouble finding the EDR of fin tube rad's that I have, but the pics in this thread https://forum.heatinghelp.com/discussion/144118/help-calculating-edr look exactly like what I have. so based on the info therein, and honestly an estimate of sizing (I didn't measure each section of radiator), but I estimated given the sizing of pipes in the thread and have 90% confidence in my estimates.

8 Feet Cast iron Baseboard - (3.4 SF per foot) = 27
(5) Fin Tube 5-1/2 x 2 x 18 (18 EDR each) = 90
(1) Fin Tube 5-1/2 x 2 x 36 (40 3/4 EDR) = 41
Total is 158.

I read to estimate pipes you multiply total (158) by 1.33 = 210

Total EDR is 210+158 = 368. Right?

I think EDR = The net steam SF of a Boiler rating. That is 521 for a Weil EG-55 https://www.weil-mclain.com/sites/default/files/field-file/WM1802_BRO_036 EG Web.pdf

So I have 521 but only need 368.

Did I estimate too much for this to be even remotely accurate?

acwagner

The boiler net steam rating actually already includes an allowance for piping. So, just compare your calculated radiator EDR (158) to the chart directly.

Piping and pickup is a 33% increase, if using your numbers it would be 158 x .33 = 51 SF for piping, or 210 total (piping and radiators).

So, yeah, your boiler is more than double what it needs to be.

denkelly

I have installed the 3psi gauge (and confirmed that the pigtail is not clogged) and I am wondering if my next course of action is messing with the pressuretrol or just getting a new one. As is evidenced below, the p-trol is set for a 1psi differential but the actual differential seems tone greater than 1.5. hard to tell as maybe I should have gotten a 5psi gauge....

I will also say that I am considering a vaporstat, as I think that I get heat in my furthest radiator before 1 psi, so having a greater level of control is something I am considering. I am imagining that since my boiler is too big, it might be best to keep the pressures as low as possible. I am looking for some input on that as well.

With the new gauge in place I have recorded my pressures.

The boiler flame turns off at just less that 4lbs. The 3psi gauge us pinned and the 30psi gauge (which shows to be fairly accurate) shows just below 4psi.

At about 2.25psi the boiler gets the call to turn back on (indicated audibly by the auto damper beginning to cycle)


This fiddling is very addictive....

ethicalpaul

> This fiddling is very addictive....

Tell me about it!

But this is good information. So you have lowered the pressuretroll to as low as it will go without the screw coming out of the spring bracket thing?

Next you could try the set screw, or buy a new pressure troll. I don't really see the value of a vaporstat for your system. Either way you want it to cut out at 1.5-2 psi and you sure don't need a vaporstat for that.

What kind of fine control do you think the vaporstat will give you that a working pressuretroll won't? (this isn't a challenge, but rather, an honest question to make sure I'm not misunderstanding your desires)

PS: 1/4" brass is better for steam than steel. Steel will gunk up faster. Someone (me included) should have remembered to mention that to you. But steel will work fine for the short term, or with attention to cleaning.

denkelly

Well, I just lowered the p-trol like you said and now everything is up by .5psi... whoops! I guess I had it at some magical setting. It's getting too hot in my house so I'm going to stop playing with this today....

My thoughts on the vaporstat are that if my furthest radiator gets hot at say .75psi then I would have the fine control to stop at that pressure and then I'm not burning gas another 3/4 or 1psi and wasting that gas. I would think it should be cheaper to run the boiler, possibly have fryer steam in the system? Then again this could be addiction talking....

I thought steel would be OK because the T on the p-troll and the original gauge was steel.... Is this really a big deal? What do you mean by "attention to cleaning"?

ethicalpaul

I would say that if pressure is building to .75 then it is a short trip to 1.5, especially with an oversized boiler, and so the operational difference between the two devices will be nearly zero. But I'm willing to be swayed!

Never trust existing conditions of your boiler, surely you must have learned that from your time here

I mean that the steel pigtail will clog quicker and so it's even more important to make sure it's clean more often than if it were brass which should be OK for annual checking. But honestly if you check either kind annually you'll be way ahead of the curve.

denkelly

You make a solid point and I have no expertise at my disposal to sway you with.

I just found a 404A 1033 on Amazon for $100 I have a 1009. I think that's the best move at this point. The set screw is caked in loctite and I think the differential is off too.

I can't honestly say I will flush those steel pipes every year, but I do flush the boiler every year so there is a chance....