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old house steam questions (18 Posts)
old house steam questions
- Background: My
husband and I own a large brick house in upstate NY. The house was built
in 1865 and has 3 floors, approx 7000 sq ft. It is separated into
apartments at this time. Ten years ago we had a new Weil MacLain boiler
installed to heat the whole house, replacing a similar sized unit. Our
plumber (who installed the boiler) has maintained and serviced to boiler
each year and so we were shocked to recently discover that the boiler
is almost completely ruined from leaking and rusting, only 10 years
after installation. We have sent photos of the damage to Weil MacLain
and they do not have any clue as to what may have caused the leak or the
damage except to say that it is not a gasket.
We are now faced with replacing this unit but we have some changes that
we would like to make - and herein lies my questions for the experts;
the current system has never been easy to regulate - if we turn up the
heat to get the top floor a livable temp, the bottom floors are hot hot
hot. Yes, we have tweaked and tweaked the system, tipped the rads, moved
the thermostat - it is just not capable of providing even heat. This is
understandable given the size of he house and the age of he system. We
would like to try to improve this situation by installing a smaller HVAC
in the top floor apartment, using the attic for vents, and use the main
boiler to heat just the 1st and 2nd floors. We are hoping that this
will make all the tenants more comfortable and will perhaps allow us to
run the boiler at a lower, more affordable temp setting. Here are my
1) if we take the rads on the 3rd floor out of commission and install
ceiling vents, can we downsize the boiler to heat only the 2 floors?
2) are minisplits a possible solution to the 3rd floor heating? will
they be able to heat the space (approx 1750 sq ft) in the coldest
3) what conditions could have possibly caused a 10 year old boiler to leak and become useless?
Thank you in advance for any help.
- Background: My
SteamWe see a lot of leaking Weil McLain boilers. It is very hard to get them to admit to anything wrong with their boiler. But, a rotted boiler is usually caused by adding an excess amount of fresh water during the winter. Fresh water contains oxygen which will rust the cast iron. This can be minimized by boiling the water any time it is added. And by keeping a close watch on the water usage, and repairing any steam leaks in the system.
Is there any copper on the supply side of the boiler? Copper will destroy a boiler within a few short years.
i would keep steam throughout the whole house. The system is not the problem. The people working on it are the problem. You need a stem expert, not just a plumber. It sounds like you have a major distribution problem that can be solved by taking the time to analyze each floor and radiator, and balancing each room with proper radiator venting. The whole system should be assessed for any improper installation practices.
Where in upstate NY are you? We may know somebody who can help.- Joe Starosielec
Guaranteed performance. Guaranteed energy savings.
Serving all of NJ, NYC, Southern NY State, and eastern PA.
locationThank you! We are in Newburgh NY - I would love to hear your recommendations as we are fast approaching the cold season and our boiler is in rusted heap in the basement!
Joe it is not the boiler from what I seeIt is always always always a bad installation. This goes for Burnham, Buderus wall hungs, and every other boiler I see that is getting a bad name.Cost is what you spend , value is what you get.
cell # 413-841-6726
Even heatingWe have a similar system with 55 radiators, and after balancing have no problems with hot spots. we do not use night setback which can waste fuel, and cause unevenness of temperature, and we keep the pressure down to 8 ounces maximum. Is your system 1-pipe or 2-pipe?
Post some pictures of your boiler and it's piping. 10 years is an abnormally short life-span for any boiler. Jstar is correct in his assumption that excessive makeup water is probably the culprit here. Is there an auto feeder? Does the boiler ever overfill?
Our last boiler gave us 35 years of service before rotting out. When talking about the replacement,boiler, make sure the heat value of the radiators is measured (EDR) and from that the new boiler can be sized (don't assume the old boiler was the correct size).--NBC
Knowledge is powerAlso suggest you buy the steamy deal of books from the shop here, so you will have more understanding of these wonderful systems. You will be more able to understand what the installer suggests (and spot the Knucklehead)!--NBC
In additionto the great advise above I would like to add a couple of things.
Uneven heat is often attributed to bad venting, for best operation you need to vent the steam mains fast and the radiators slowly. The slope of all mains should be checked to make sure they are correct. That should allow all the radiators to get hot at about the same time. What kind of main vents do you have and what kind of radiator vents?
I know there were a lot of boiler failures between Boston and Providence cause by chlorides in the water. i have not heard of this problem being a problem in NY but I would ask about it and check with homeowners in the area to see if they have had similar problems.
Make sure the installer you select to replace this boiler knows steam systems, there are not a lot of good steam men out there but most of the good ones belong to this site so the advise you get here really is the best available. Buy the books so you will know enough to ferret out the good installers.
BobSmith G8-3 with EZ Gas @76,700 BTU, Single pipe steam
Vaporstat with a 12oz cut-out and 4oz cut-in
3PSI gaugeThis post was edited by an admin on September 6, 2013 7:41 AM.
Old Steam SystemsHi- It might help if we knew more about your present system. Is the boiler gas or oil and if oil, is natural gas available? Pictures of your present boiler would be also a help. Take the pictures from farther back so they include the piping attached to the boiler. This way we can trace out the piping and determine if there are problems with the piping configuration.
What typically happens with these old steam systems is that the original installers knew what they were doing and installed a perfectly working steam system and then over the years other people (who didn’t really understand steam) have done maintenance on the system and their “mickey mouse fixes” have disrupted the system so that you get problems like uneven heating.
The solution is to remove the remove the “mickey mouse” and restore the system to its original configuration. To do this you need to find a “steampro” and learn about steam yourself. Competent steampros aren’t that easy to find. Many people in the heating business think that they understand steam but surprisingly few do. Most steampros are good plumbers, however, few plumbers are good steampros. This is where reading Dan’s steam books comes in. I would start with one called “We Got Steam Heat!” It’s available from the Shop section of the Heating Help website. Here’s a link to it:
All Dan’s books are easy reading and written so that the homeowner, new to steam, can understand them. A few evenings of reading will put your knowledge of steam heating light years ahead. “We Got Steam Heat!” is a good introduction to steam heating and one of the important things you will gain from reading it is the knowledge to be able to decide whether the heating professional you are talking to really understands steam heating.
I see others have recommended “The Steamy Deal” http://www.heatinghelp.com/products/Steam-Heating-Books/25/129/A-Steamy-Deal
This is the complete set of Dan’s books on steam. All of them are good reading and basically go into steam heating in greater depth than does the introductory “We Got Steam Heat!” If you are replacing a boiler the whole set would be beneficial to have.
Switching away from the steam books, are you familiar with TRVs? These can be used to control overheating. They are also beneficial in that they allow you to shut down parts of your house in winter. I have a 3 story house in central Maine and use TRVs to save fuel by turning down the heat in the rooms my wife and I aren’t using. Rather than shutting the radiators in those rooms completely off, the TRVs keep the room at around 45 degrees so that the pipes in the walls and the plaster doesn’t freeze.
Let us know what questions you have. The Pros and the homeowners on this site are very helpful.
This post was edited by an admin on September 6, 2013 11:19 AM.
wow!My husband and I have read your replies with keen interest and we just purchased the Steamy Deal books - THANK YOU so much for your input! We are starting to see a light through the trees. I will post pictures on the rusty, dismantled boiler now.
Boiler PipingHi- Thanks for posting the pictures. They are a big help. In looking over your photos it would appear that you have some serious problems with your boiler's piping configuration.
Having the Steam Riser Pipe attached to the Header Pipe so that it is located between the attachment of Boiler Risers “A” & “B” is a BIG “NO NO”! Having the piping this way produces very wet steam. Wet steam is inefficient and uses more fuel. (See attached diagram)
The elbow connecting the Header pipe to the Equalizer should be the same size as the Header Pipe and not reduced in size until on the vertical otherwise water is trapped in the header and doesn't completely drain. (See attached diagram)
The pipe nipple connecting the Return piping to the Equalizer piping should be a close nipple otherwise water hammer (“banging”) can occur. The “Mickey Mouse” return piping needs to be straightened out also.
Here's a video of Dan's on the importance of proper boiler piping configuration:
Glad to hear you are getting the steam books. One of the benefits in you having them is we can answer your questions by referring you to a certain page in the book where Dan explains the answer farther better than we can.
Let us know what questions you have and we'll do our best to answer them.
- RodThis post was edited by an admin on September 6, 2013 2:39 PM.
The Steam Train and Wet SteamHi- After further thinking over your situation, I would suspect that "Wet Steam" may be the root of your system's problems. In a large house where steam has to travel up 3 floors it maybe that due to the steam being wet, that the majority of the steam condenses in the piping before reaching the third floor radiators. Having to run the system for a long period of time so that the top floor radiators are finally getting hot (while the lower floors are roasting) would seem to be a possible indication of this.
I've attached a PDF on "The Steam Train" which gives a better explanation of this. I wrote this up back in August to explain it to another homeowner.
Wet SteamYou're absolutely right about wet steam being the crux of the distribution problems, but it also might be partly responsible for the failure.
Steamhead has said that the leading cause of failure in the boilers he's replaced--and boy has he replaced a lot of boilers--is a fluctuating water line. He mentions leaks, below, which cause long-term fluctuations, as the water runs low and has to be topped up continually, and also leads to the problems that JStar discussed above, but wet steam causes short-term fluctuation by loading the system with water that gradually returns, loaded up with rust, during the off cycle. The wet steam also contributes to the system leaks Steamhead mentioned by corroding pipes and radiators and damaging vents and valves.
I suspect the swing-arms beings so short might also be a factor, although my boiler lasted almost 30 with no swing-arms at all. If this model had elastomeric gaskets instead of steel push nipples between the sections it would be more susceptible to being pried apart by the piping.1983(?) Peerless G-561-W-S
3" drop header, CG400-1090, VXT-24
The way that boiler rotted outtells me that system has some leaks, and the resulting hole in the boiler section is probably right above the waterline. I bet when that boiler comes apart you see something like the one in this thread:
or this one:
or this one:
You get the idea. Check all the valve packing nuts and air vents for leaks- I think you'll find a lot of them! Also if you have any underground return lines, they're probably leaking too.
When you replace the boiler, make sure the contractor installs properly-sized main vents too. This will reduce the boiler's running time by speeding up steam distribution."Reducing our country's energy consumption, one system at a time"
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Baltimore, MD (USA) and consulting anywhere.This post was edited by an admin on September 6, 2013 6:27 PM.
thanks to allThank you Rod, JStar, nbc, BobC, HapHazard, Steamhead - thank you all very much! We are moving forward armed with your excellent advice!
2-stage gas valveOn some boilers, of the size your's must be, there is an option for a 2-stage gas valve. Therefore when the boiler fires up from cold (0 pressure), the fire is high. As the pressure rises to 2 ounces, the controlling vaporstat will signal the valve to drop to low fire, just maintaining that low pressure. What is essential, although somewhat costly is adequate main (not rad) venting, verified by a good low-pressure gauge (0-3 ounce--gauge store.com),, next to the code required 0-30(useless for our system diagnostics).
This would be worth looking into. I wish I had such an option, but it was an expensive afterthought on my 1,000,000 BTU.--NBC
with knowledge comes more questions!Thanks in advance everyone for all your help. I'm dozergrrls husband. We have Dan's books (they arrived today) and have spent lots of time mulling over our predicament with all the new info you all have given us. Here is the latest question, we are thinking we may have a wet steam situation (based on system performance, not corrosion). We're wondering could we have a wet steam problem without hammering? We have never noticed hammering/banging in the house and have never received reports of such behavior. As we get into the books the answer may be there but what do you all think?
Wet Steam & Water Hammer in a Steam SystemHi - Glad to hear you got the steam books as they will be a great help to you.
Wet steam doesn’t necessarily produce hammering (noise). In a steam system loud water hammer (banging) only occurs when a large bubble of steam gets trapped with condensate (water) on both sides of it. When steam collapses (condenses) it instantly reduces its volume by 1728 (1 cubic foot of steam to 1 cubic inch of water.) This creates a huge vacuum void and water (and water droplets) rush in from all sides of the void to fill the void. The noises you hear are from the collision of water crashing together in the void. Large bubbles of collapsing steam produce a “Bang” and small bubbles produce a “Click”
Here’s a link to a good video that shows collapsing steam and the noise it produces, (Be sure your audio is on) http://www.kirsner.org/pages/WaterCannonVideo.html
Water hammer in a steam system is usually the result of improper piping configuration or something like sag in the piping that would cause water to “pool”. Condensing steam doesn’t necessarily produce noise. In a properly working radiator steam is collapsing constantly yet you normally won’t hear any banging. (In fact most of the noise produced is from condensate (water) running down the inside walls of the radiator.
The ultimate goal is having a system that produces dry steam.
This is accomplished by:
1. Having a good steam /water separator - this is the header pipe and the properly configured boiler piping. As your present system near boiler piping is configured, as I mentioned in a previous post, with the opposed boiler risers , it has to be producing a lot of wet steam.
2. Having good boiler water quality - Reasonably clean water and low surface tension.
This is accomplished by the occasional cleaning of the system and a thorough skimming of the surface of the boiler water to remove contaminates like oil.
Attached are some pictures by Noel Murdough of his boiler, with glass piping, in operation. The picture labeled "Dry Steam" is how dry steam would normally look. He then added a tablespoon of oil to the boiler water and the results are water/steam output you see in the picture labeled "Wet Steam". The adding of the oil was to show the different of steam quality on a boiler that has boiler water contaminates and hasn’t been skimmed and a boiler that has good boiler water quality. The adding of the oil increased the surface tension so that now the steam has to gather in larger bubbles in order to break through the water’s surface. This violent break through causes water droplets to be carried along with the steam and up into the mains. With good quality boiler water, the steam bubbles produced are small and “fizz” to the top like the bubbles in a glass of champagne.