Steam boiler start of season maintenance questions.

jtor1134

In addition to dealing with a leaky valve I know I need to do some sort of maintenance on my boiler before I fire it back up this weekend. Some background info, I moved into this house last December, and the boiler worked flawlessly all winter. I did flush it a couple of times to get some of the sediment out, because I don't know when it was last serviced. Once the summer came I made sure it was full, closed the valve to the automatic feeder, shut the switch off and turned off the gas supply.

Now the summer's over and I'm ready to bring it back into service. Aside from maybe changing the water in it again (I was manually filling it while draining it into a bucket) what else am I supposed to do before lighting the pilot light? Here are some pics of the boiler itself.

It seems it was serviced by the gas company according to the sticker some years back, which brings me to another question. What exactly do they do during a "tune up" or "pm check"?





Also another question. This boiler is from 1989 I think? How long can I reasonably expect it to last? I know it's going to cost a fortune to replace, and I'd like to at least prepare for the eventuality.

HVACNUT

I believe your boiler is newer than 1989. There should be a white or yellow sticker with a CP#. That's the serial number. You can call WM to check the age using that.
You shouldn't be changing the water. A quick flush every couple months to get the muck out because you have a probe LWCO not a float type.
You should have a pro check the boiler annually, or get a maintenance agreement. Getting someone there at 3:00 A.M. in February when you have no heat isn't exactly fun when they tell you contract customers are priority and maybe we'll get there next Tuesday.

jtor1134

Hah. You’re right. It’s actually from 1991. Good to know about not changing the water, that’s something I’ll stop doing.

My question is what is a pro going to do as a part of his annual check?

nicholas bonham-carter

Is this a 1-pipe system? Find your main vents on the returns, and send us a picture of them, as well as the front of the pressuretrol, so we can see the settings.
Don’t change the water, as it does not wear out, although it can be contaminated with oils left over from the installation, even years later, (see skimming). These oils cause the boiling to be erratic, and inefficient, if still present, due to an improper initial cleaning.
Clean the sections of the boiler, to clear them of any dust, and check the combustion with a device known as a combustion tester.
Check your chimney by looking up from the cleanout door, to make sure it is unobstructed, and change the batteries of your CO detector!—NBC

jtor1134

Yes, this is a 1-pipe system. I have a picture of the pressuretrol on my phone so here it is.


I’ll take a pic of the main vents later when I get home. I do have a new CO/smoke detector installed about 5 feet away from the boiler.

BTW this brings me to another questions regarding the boiler’s behavior. I believe it’s “short cycling” if that’s even a valid term here. Basically the boiler will run until the pressuretrol cuts it off at 2psi, and then after several minutes the pressure will fall and the presssuretrol will fire the boiler back up again, 5 minutes later it reaches 2psi again, shuts off, and then rinse and repeat until the thermostat is satisfied. I’m assuming it’s not supposed to work this way.

Temporarily re-arranging my automotive technician neurons, this is telling me that one of these things are happening:

- Pressure is set too high (even though 2psi sounds like nothing to me).

- Boiler is too big.

- Something is leaking.

None of my vents are leaking/hissing constantly. And i would expect some pressure drop as the steam cools as the radiators...umm... radiate.

My theory about the boiler being too large are based on the fact that I have a 122k BTU boiler in a 1200 sq ft house. According to supplyhouse.com’s boiler size calculator, it should be more like 55k BTU. Now I now an online calculator is no replacement for doing it properly but that’s a huge discrepancy. If the boiler’s too big then it only needs to run for a very short time to fill my small system with steam, whereas a smaller boiler would need to run more or less constantly to maintain pressure without the pressuretol kicking on and off constantly. Am I on the right track here?

Jamie Hall

The pressure cycling which you mention is just what you think it is -- the boiler is bigger than it needs to be. Probably quite a bit bigger. To compare it to your automotive technician neurons -- suppose you have a 230 hp engine in a little compact -- say a Civic -- and the throttle only has two positions -- full on or idle. The only way you can control the speed is to alternate between the two. That's what your boiler is doing. Not ideal. Changing the pressure setting won't help. If you get a low pressure gauge (say 0 to 3 psi) and put it on there, and check it from a cold start, what you want to see is the pressure rising to about half a psi or so and then nearly plateauing for a while, then rising again to where the pressuretrol cuts out. This can tell you a lot. If the plateau region is much over that half a psi or so, you need more main venting. Then, the run time after the plateau isn't helping a bit, so you can set the pressuretrol down -- carefully -- to about as low as it can go (careful doing this -- there's a linkage in there which can and will disconnect itself if you try to go too low, which is a pain).

jtor1134

Thank you for the information and confirmation of my suspicions. Well unfortunately there’s not too much I can do about the boiler size right now.

Here some pics of my main vents and the piping side of the boiler. Can you tell by the numbers what size they are and what might work better?

JUGHNE

Any other info printed on the steam main vents?
They remind me of hot water vents...…

What are the lengths and size of the main steam lines.
And back up and more pictures of the vents and their location would help.

JohnNY

That boiler is installed completely wrong and those vents aren't for the type of system you've got. They're not for steam at all. You've got some work to do there.

JUGHNE

Installing steam main line air vents is the low hanging fruit here.
Length and size of steam main pipes would give us a good indication of needed vents.
More venting would cut down on the short cycling somewhat.
If boiler is massively oversized you will still have short cycling but the vents would lessen that and improve steam delivery.

The boiler and radiators should match in EDR sizing.
This size is determined by the coldest day of the year (perhaps with some windows open) and so most of the time the boiler is too big.

We need those pictures of vent locations and how the piping is for them.

Fred

You should leave the pilot light on during the off season. That helps to keep the burners and other components dry and free from moisture/eventual corrosion.
Start up Maintenance:
- Test the Low water Cut-off to make sure it shuts the boiler down when the water level gets below the probe or float.
- Test the Auto water fill to make sure it adds water when the boiler is low and that it shuts off when the Normal water lvel is reached
- Take the Pressuretrol off and remove the pigtail (looped pipe) and wash it out. They will get clogged and the Pressuretrol can't actually see the system Pressure.
- Run the boiler a couple cycles and make sure all the radiator and Main vents open and close properly. Make sure your Main vents are large enough to vent the mains efficiently.
- While you are checking the Main Vents, walk the perimeter of the basement (around your Mains) and make sure there are no obvious leaks.
- Check your Wet returns for any leaks and, if you have drains on those wet returns, open them and flush the crud out of the wet returns.
- Oder a bottle of Steamaster Tablets and add one or two tablets (no more than that) to your boiler water. Add them to any opening you have to the boiler block (Skim Port, opening where Pig Tail is installed, when you have it off to wash, Pressure Relief Valve opening)
- Test and/or replace the Pressure Relief Valve. If you test it and it continues to drip after the test, replace it. (Make sure you are aware that steam will blow out of it so be very careful and only open/close it very quickly.
- If the burner hasn't been tuned in several years, get it cleaned and properly adjusted by a professional, with the proper equipment Combustion Analyzer) to make the adjustments.

Sounds like a lot but there really isn't much time involved, maybe a hour or two at most (plus the Professional Burner cleaning and adjustment)

jtor1134

Just measured them. The main steam pipes (the fatter ones) are 2.5” OD, the smaller return pipes are 1.35” OD. By length, do we measure them for the whole house? Meaning the horizontal part in the basement and then all the way up the the 2nd floor? The basement is partially finished but I’m going to assume they run to each end of the house.

> @JohnNY said:
> That boiler is installed completely wrong and those vents aren't for the type of system you've got. They're not for steam at all. You've got some work to do there.

Oof. What else do you see wrong aside from the incorrect vents?

Oh and some more pics. This is the best I can do as it’s a small room.

Fred

The near boiler piping is just all wrong. How does it run? Is there a lot of banging/hammer when it runs? Does the house heat evenly?
The things I can immediately see wrong with the near boiler piping are:
- There is no header
- Since there is no Header, the Equalizer doesn't run off of the end of the header, instead, it is tied into the riser to the Mains
- There is a Bull Tee at the top of that riser where the Mains run in opposite directions, off of that Tee. Each of those Mains should drop down into a properly installed Header.
- Those dry returns that are Tee'd together above the boiler water line should drop to the floor and then tee'd together rise back up into a Hartford Loop. That will keep the lower portion of both returns filled with water and prevent steam from entering the Returns, causing water hammer.
- As has been said, those are the wrong vents. It sounds like you have 2" and a 1.25" mains. (ID). How long are they? That will determine the size vent you need. Just measure the length of the actual Main, in the basement, not the individual radiator Run-outs (those are vented by your radiator vents). If there is a main riser that goes up to the second floor and the radiators branch off of it, that riser should also be measured and vented. If the risers are individual and run to each second floor radiator, again, the radiator vents will handle those.

Having said all that, if it is running ok and isn't hammering a lot, given the age of the boiler, you may want to wait and have all of that corrected when the boiler is replaced. The vents need immediate attention.

jtor1134

Honestly it works just fine. No banging/hammering, and in fact it doesn't make a peep. Heat seems pretty even. The only thing that made me think something was wrong is listening to it short cycle since my office is in the basement I get to listen and observe it a lot.

As far as measuring the mains, I honestly have no idea where it goes but I'll try and investigate. I'm assuming there's a riser that goes to the second floor. There would have to be one wouldn't it?

BobC

Each main will run from the boiler to the last radiator takeoff (could be 1st or 2nd floor radiator) and then back to the boiler where the vents are. We need to know how long the run from the boiler to the last radiator takeoff is and what size pipe is being used for the main. This measurement does not have to be exact.

Bob

jtor1134

Ok so it seems one main is 120 inches, and the other is 123 inches (not including the return pipe).


This is a finished basement but it fortunately does have a drop ceiling so I can see some parts of it. I can see the pipes for the individual radiators on the ground floor, but there is one take-off on each main that that I cant identify. They go up through the floor and since there's no radiator in that location on the ground floor I can only assume they go upstairs to the 2nd floor. One probably is for the master bedroom, and on the other side would be for the bathroom and 2nd bedroom. What do you think?


PS. Thank you for this!

jtor1134

Oh one other thing. It just occurred to me to look at the tops of the main vents for further info.



This appears to be a Taco 418 and according to this, it's not suitable for steam heat. https://s3.amazonaws.com/s3.supplyhouse.com/manuals/1346680696961/78511_PROD_FILE.pdf

Dave0176

@jtor1134 those vents are for a Hot Water heating system. Look at Gorton steam vents you need either a number 1 or a number 2. You can also look on Amazon for Barnes & Jones Big mouth air vents, these are probably the best vents you can buy.

Fred

Those are fairly short Mains. A Gorton #1 on each main would be fine. The two pipes going to the second floor are technically radiator run outs to the second floor radiators and the radiator vents on those radiators should be fine. If those radiators are slow to heat, you could put a vent on the pipe before it goes into the radiator but it isn't necessary unless you aren't happy with the way those radiators heat.

jtor1134

Awesome. Thank you guys very much. I'll order the new vents.

Next question. I just fired up the boiler for the first time since the winter and tested things. LWCO is good. Auto feeder only runs until the LWCO is satisfied so it's not good for filling it up to the water mark but I assume that's how it's supposed to work since the feeder is powered by the LWCO. Pressure relief valve is good. Cut out pressure as it was is 4psi, and it kicks back on at around 1.8 psi. I adjusted the pressuretrol to cut-in .5 psi and diff of 1.8 or so. We'll see how that goes.

Only issues I found are that one of the radiator unions is leaking like a sieve, but I already knew about that. It's worse than it was though so it needs immediate attention.

The other issue is I have a small leak at the boiler's lower nipple where it looks rusted out.



There's no way in hell I'll be able to replace this myself so I'm probably going to need to call someone. I'm wondering how labor intensive this is going to be though since it seems like all of that **** needs to come apart, but I'm no plumber so maybe it's easier than it looks.

Fred

That Radiator union probably just needs to be tightened up a bit. They will sometimes work loose with all the expansion/contraction. That nipple at the boiler is going to take a little work. Are there any unions anywhere near it that will let you take the union apart and take piping loose back to that nipple? That may be a job best left to a professional.

I'm guessing that you will see a noticeable difference in the short cycling when you get the correct vents on the system. In any case, don't turn the Pressuretrol back up to where it was. That's too high and, though it may seem counter intuitive, Steam moves slower at higher pressures. which makes the heating cycle longer and that contributes to the short cycling by the time the thermostat is satisfied.

jtor1134

What about if I JB welded it for now? It can't hurt I think, and if it doesn't work the nipple still needs to be replaced as well as the elbow it's screwed in to.

Dave0176

jtor1134 said:

What about if I JB welded it for now? It can't hurt I think, and if it doesn't work the nipple still needs to be replaced as well as the elbow it's screwed in to.

That may work, I’ve seen it done however you don’t want corrosion to get any worse and start corroding the boiler, so it’s best to have the piping replaced now while it’s easy.

JUGHNE

As far as your new steam main vents, it is recommended to not install them at the end of the return as they are now located.
Imagine a slug of water and steam rushing to the end of the pipe and hitting that 90 elbow, (AKA water hammer). Water and debris would hit the wall of the fitting and possibly shoot up into your new air vent.

The easy way to avoid that is to put a 90 with a 6-8" long horizontal nipple and then a 90 going up maybe 6" or so to the air vent.
That gives you some cushion between your air vent and the large 90 where the water hammer might happen. Easy to do, just be sure the horizontal pipe will slope to drain back to the large piping, avoid any water pockets.

jtor1134

Seems easy enough. My question is how do I introduce a slope? Is it sufficent to just do this? (Picture taken from Dan Holohan’s book).



Can I just use 45 degree elbows instead (assuming I have the ceiling height).

gfrbrookline

It looks like you would have enough clearance if you use a big mouth. It cost the same as the gorton #2, vents almost twice as fast, and is built like a tank. I have 6 of them on my much larger system. I would install a 1-3 psi gauge next to the required 0-30 which code requires but is useless. This will confirm if the pressuretrol is working correctly. If you experience any short cycling on pressure add more than one vent on each main to reduce back pressure and make the system heat more evenly and efficiently.

Fred

gfrbrookline said:

It looks like you would have enough clearance if you use a big mouth. It cost the same as the gorton #2, vents almost twice as fast, and is built like a tank. I have 6 of them on my much larger system. I would install a 1-3 psi gauge next to the required 0-30 which code requires but is useless. This will confirm if the pressuretrol is working correctly. If you experience any short cycling on pressure add more than one vent on each main to reduce back pressure and make the system heat more evenly and efficiently.

You need to make sure the tapping(s) on each main is large enough to let the air flow be equal to or greater than the vent(s), otherwise, you're just wasting money on vents that are limited by the tapping on the main.

gfrbrookline

I agree, I have two mains on my system, both 2" and approx 60' long. The vents are on the dry returns, 3/4 tapping, so 3 big mouths massed out the venting capacity of the tapping according to the venting charts in LASH. Increasing the vents cut my boiler run time by 1/3rd so I was able to recoup the investment in one heating season. Money well spent.

I started with one on each main and worked my way up watching the pressure drop with each additional vent and checking to make sure they were heating equally.

JUGHNE

The picture from the Dan book is the "textbook" example of installation. The air vent looks to be 16" back from the drop elbow where the water hammer could occur.

You get the same protective effect by bring a separate pipe off your elbow and relocating the vent away from that elbow.

You establish the slope by using a 90 off the top of your existing drop elbows. The new horizontal pipe would be parallel to the return pipe and point in the uphill direction that the return does.
That should give you the same slope of the larger return pipe.
Just enough slope on your venting piping so as to not hold water.

You want your new air vents very near vertical so any water in them will drain back down during the off cycle.

jtor1134

Right, but what I’m asking is how to physically create that slight slope. Bend it?

JUGHNE

Do your return pipes show any slope with a level?

jtor1134

I havent checked but I would imagine so. The thing is I’m not sure that would even apply here. One vent is already mounted on a 45 degree elbow to clear an unrelated duct, and the other is on a tee fitting and not on the return pipe itself. There may or may not be a slope there if I were to put a horizontal pipe on the end of that tee. That’s why I was wondering if I could either just bend the 6” or so nipple up slightly to introduce that slope, or if I could just use 45’s and make a huge slope.

JUGHNE

Both of these are "dry returns", that is to say when the system is off and cold these pipes should have drained down back to the boiler.
They most likely are doing that now or you would have water hammer if any fair amount of water stayed in the dry returns.

The left one in the picture, IIWM, I would remove the 45 elbow.
Replace it with a 90 and point it to the left.
Get or build a 12" long nipple, install into the 90 so it is running parallel to the left dry return. Your new nipple would have the same draining slope as the return pipe. Add a 90 pointing up, to the end of that new nipple. Raise your new air vent up as high as practical with vertical nipple.

For the right one, remove the coupling, install a 90, add a close nipple and another 90...….this gives you a "swing 90".
With that you can add your horizontal 12" nipple headed in any direction and adjust it with a bit of slope to drain. Add the 90 to the end with the necessary nipple pointing up for the new air vent.
Keeping just enough slope on the horizontal will result in your vent on the 90 being almost vertical......close enough.

Please post pictures when done. Thank you.

You don't want to try to bend a nipple that is screwed into either of those cast iron tees...…...they can crack....I know this.

jtor1134

Hey just out of curiosity, how much force should I have to use to loosen these fittings. I just tried to use a 14" pipe wrench to loosen the 45 on the left one and it doesn't want to budge. I didn't give it all I had and I also have a 24" wrench I can use but I'm being cautious. Definitely don't want to break anything.

Fred

It can take some persuasion, for sure. Always Use two pipe wrenches, one to hold the section of pipe you don't want to remove (below what you are trying to remove) and one to turn the fitting/vent/valve you are trying to remove (opposing directions on the wrenches)

jtor1134

Yes I'm definitely using 2 wrenches, I just don't want to go full gorilla on the thing if there's something else I should be doing instead. If this was a car I would take a torch to it but I don't feel that is a good idea here.

Fred

You can always soak it with a little Kroll or other penetrating oil and let it soak in for a day or so, tapping it occasionally to set up a vibration.

jtor1134

Ok that wasn't too bad. My local plumbing supply said they had the Gorton valves in stock but when I went to actually buy them he said that they only have Maid-o-mist. I would have preferred getting what was recommended here but according to him it's the "same ****" so I ended up buying them as well as the needed pipe fittings.

How'd I do?





I wanted to use another nipple to extend the height of the valve but I just didn't have the ceiling height. Even with a 3" nipple the valve would have been mooshed into the insulation. I think this should work pretty good no? I was certain to make sure they're on an incline so the water can drain back.

Now I fired the boiler up and so far so good. No leaks. I'm not sure if I can tell a difference but it seems that it takes longer for the boiler to reach the 2psi pressuretrol cutoff, and (most) of my radiators are good and hot before it happens. I'm not sure how to tell if the vents are working, because you can't hear them and even if I put my finger over the hole on the top I didn't feel any air coming out. All I know is that while the boiler was running the piping and vent went from cold to hot as hell not gradually, but all of the sudden, so I'm guessing that's what's supposed to happen.

Next thing I noticed, which may have been the case before, but might have been made more obvious with the new main venting is that a few of my radiators seem to take a looooong time to heat up. We're talking still ice cold while the one in the room next to it is already cooking. So I'm guessing those are going to need better vents. Currently they have varivalves like most of the house does but I've heard they have a pretty high failure rate so I'm guessing I should change them.

Fred

What is the number on those new Maid-O-Mist vents? We suggested the Gortons or the Bigmouths because of there venting capacity. Those MOM's may not be any better than what was already on there.
Once we are sure the Mains are properly vented, you can begin to balance the radiators. Varivents are problematic. They tend to vent so fast that all the radiators may not get steam because others are hogging all the steam. They are also not the most reliable.

jtor1134

It's this one. Supposedly it's roughly equivalent to the Gorton #1.

https://www.supplyhouse.com/Jacobus-Maid-O-Mist-J1-1-3-4-x-1-2-Main-Vent-Valve-3563000-p

Are you supposed to hear/feel them venting?

Fred

That Maid-O-Mist #1 is exactly the same size as the Gorton #1, which is only .33 CPM. With Mains that are only 10' long, they should be OK. You probably won't hear them venting but if you hold a tissue up to the vent port, when steam begins to move into the mains, you should see the tissue flutter a bit.