Improperly Piped Steam Boiler

cheezhd · October 2017

Hi,

I'm looking for some advice with a dilemma I'm having. I inherited a residential steam heating system with an improperly piped boiler--there's no header, the riser connects directly to the steam main (pictures below). I lived with the system last winter. It did its job of warming the house in a reasonable amount of time, but the heating bills were high and the radiator vents were noisy. I could see steam coming out of the vents, so I'm guessing the improperly piped boiler is producing wet steam. The radiator vents are old, have been painted over, and probably need to be replaced. The boiler is also significantly over sized at 128,000 BTUs when my EDR calculation suggests I only need around 57,000. Other than all that, the boiler itself seems to be in fine shape and not in need of replacement in the immediate future--I believe it has been in service for about 5 years.

So I'm wondering the following:

(1) Is it worth it to have the boiler re-piped properly now or does it make sense to just wait for the current boiler to need replacement in say 5 years and then get everything done right when I replace the boiler?

(2) Will it just be a waste of money to replace the (old) radiator vents because the wet steam from the boiler will cause them to hiss and clog regardless whether they're new?

Thanks in advance for any wisdom you can provide.

markdelzell · October 2017

Since the radiators are oversized for the heat load convert the system to hot water. Remove orifices in traps you only need 1 gpm to get 10,000 of heat to radiator. May not need pump looking at piping.

ChrisJ · October 2017

I would certainly get the piping fixed and good tech may be able to downfire the boiler some.

It's only 45% too big, and most recommend a 33% pickup factor so you only need to drop 12% to get to that point. I'm assuming you used the DOE output vs your EDR?

cheezhd · October 2017

Thanks for the reply ChrisJ. I used I-B-R. DOE is 171,000.

gerry gill · October 2017

Repipe the boiler.

Danny Scully · October 2017

Where are you located @cheezhd?

cheezhd · October 2017

Okay, you have convinced me to re-pipe. I'm located in New Haven, CT.

Steamhead · October 2017

Don't even think about converting that system to hot-water, unless you like living dangerously. First off, the much higher pressures involved with hot-water- at least 12 PSI as opposed to ounces of steam- will do a great job of creating leaks if there are any weak points in the system.

Also, the OP says "The boiler is also significantly over sized at 128,000 BTUs when my EDR calculation suggests I only need around 57,000." So this is a case where the boiler is oversized for the existing radiation. No mention was made of whether the existing radiation is oversized for the house. Since a hot-water radiator of a certain EDR will only emit roughly 2/3 of the same rad on steam, converting to hot-water would likely produce a system that falls short on really cold days.

So don't do it.

That boiler looks like the Smith clone of the Peerless 63 series. These are quite well-made and should last a long time with proper care. I'd say repipe that boiler and down-fire it as much as possible while still maintaining good combustion, as measured with a digital combustion analyzer. Also replace the leaking radiator vents and add or upgrade main vents as well.

@cheezhd , are you located in Wisconsin?

Fred · October 2017

I agree. Keep the steam, re pipe the boiler, add good main vents and replace the radiator vents. Look in the "Find A Contractor" Tab at the very top of this page and enter your zip code. Most of the Steam Pros listed will do a great job for you and, as has been said, properly maintained, that boiler should last another 15 or 20 years. Post the name of the contractor you find on here and we can validate that we have seen and are familiar with their steam skills.
Many of us have boilers that are well over-sized for the connected radiation and we make them work beautifully.

cheezhd · October 2017

@Steamhead Really appreciate the thoughtful reply. My house is over 100 years old, and I'm not inclined to see whether the old pipes will hold up under increased pressure. You're also correct that the existing radiation is well-sized for the house. The boiler is a Smith GSX 206.

I'm in New Haven, CT. But family is from Wisconsin, hence the cheezhd handle.

cheezhd · October 2017

@fred I didn't see any contractors within an hour or so of New Haven using the "Find a Contractor" tab. Someone offline recommended Bruce E. Stevenson III to me. He is the third generation of family plumbing and heating business.

Fred · October 2017

@cheezhd, have him show you some of his steam installations and, if you can post a couple on here. We can tell you quickly if he knows what he is doing, as it relates to Steam installations. At a minimum, make sure he installs it per the Owner's manual. Those are minimum standards. If he could install a Drop Header, that would be a plus. Make sure he doesn't use smaller diameter piping just because he can't cut or thread the correct size. Make sure he installs good quality and adequate capacity venting at the ends of each Main. You can change out the radiator vents yourself, just don't buy cheap or Chinese ones. They don't last. I like the adjustable ones like the Hoffman 1A or the Vent-rite #1. Good quality and you can use the same vent on each radiator and adjust them to vent faster or slower, depending on how much heat you need/want in each room. Don't skimp on the installation. It is as important as the equipment itself. Once it's done right, do the annual maintenance. That too will ensure you have that boiler for many years to come. Minimize the amount of fresh water that gets added to the system. If fresh water has to be added often, there is a leak somewhere that needs to be addressed pronto. Large amounts of fresh water is probably the biggest enemy for a steam boiler. It will rot the boiler out in less than half its normal life.

MilanD · October 2017

As the other guys said - repipe. Make sure also your operating pressure is low. Using vaporstat is the best way to ensure low pressure (with a clean pigtail). This may be why your rad vents are leaking - excessive pressure. Any system needs only 1oz per 100ft of pipe. That's ounces. While at it, add a 3 psi gauge to your controls cluster. Good job on the big mouth vent.

And one last thing, I see you have a cst gas line - make sure it's bonded to the ground bar on your electrical panel. There should be a clamp on it right by where it turns cst, and at least a #6 wire to bond it with.

Steamhead · October 2017

cheezhd said:
@Steamhead Really appreciate the thoughtful reply. My house is over 100 years old, and I'm not inclined to see whether the old pipes will hold up under increased pressure. You're also correct that the existing radiation is well-sized for the house. The boiler is a Smith GSX 206.

I'm in New Haven, CT. But family is from Wisconsin, hence the cheezhd handle.

OK, we use the IBR Net rating when discussing steam systems. That's 533 square feet EDR/128,000 BTUH for the GSX-206. This rating has the 33% pick-up factor built in so we don't need to figure it in when sizing a boiler. In some cases a smaller pickup factor might work, but the built-in one usually works well. Also, in some cases a larger pick-up factor is needed, such as on a system where a lot of radiation has been removed.

Jamie Hall · October 2017

One further thought (echoing @Steamhead particularly, and others). First thing you can do -- and you can do it tonight -- is go to the basement, take a look at the old beast, and make sure the pressuretrol (which I don't see in any of the pictures, but it must be there somewhere...) is set properly. If it is a pressuretrol -- most likely -- set it to cut out at about 1.5 psi. That will help everything...

BobC · October 2017

I agree with @Jamie Hall about making sure the pressuretrol is set as low as it will go. Getting that boiler repiped is not going to be cheap but there are things you can do to improve the systems performance while waiting to have it repiped. How many steam mains do you have and what size main vent is on each steam main? First buy a copy of Dan Holohans "The lost Art of Steam Heat" (you can buy it on this site or Amazon) it's the best investment you can make.

Next draw a rough diagram of your steam piping showing each radiator and how it connects to the steam main. That diagram should show the EDR of the radiator, the approximate length and diameter of the pipe that connects it to the main.

Once the steam pressure is as low as it can go start replacing the radiator vents, the information you get from doing the drawing could in theory, allow you to plan what size vent goes where. From a practical point of view it's easier to use adjustable vents like the maid o mist 5L (with 5 orifaces0 or the ventrite 1a; with these you can dial in the correct venting. I n general you vent the radiator slowly and the steam mains fast. Start with all the radiators being vented at the lowest settings and then slowly increase the vent rates for any that heat slower than most. The goal is for them all to heat at about the same time.

Bob

nicholas bonham-carter · October 2017

Replace the main vents first, with adequate capacity.
Check the pressure with a good low pressure gauge, (0-3 psi), from the gauge store. If the pressuretrol cannot function, get a vaporstat.
At least the original installer left you 2 risers out of the boiler with which to install a drop header, and you might consider doing that yourself.—NBC

Improperly Piped Steam Boiler

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