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Steam

Steam 121 Articles

  • Vacuum Pumps and Common Sense

    *Many big buildings in our older cities use vacuum pumps to create a negative pressure in their condensate-return lines. This below-atmospheric pressure, which averages around 5.5 inches of mercury, lets the Empire State...

  • Reflective insulation behind steam radiators

    Reflective insulation behind radiators makes steam-heating systems more efficient.

  • Piping Past Obstructions in One-Pipe Steam Heating Systems

    Here’s how you’d pass a steam main over a steel beam: piping around steel beam The pitch is in the direction of the flow. The steam goes over the beam through a...

  • Watch an infrared film of a steam radiator getting hot Video

    Reinvent is the nickname of one of the members of The Wall. This is a time-lapse film that shows how steam is lighter than air and will go to the top of...

  • Do I need to flush an old radiator from time to time?

    No. Hot water radiators operate within a “closed” system where there’s little or no corrosion taking place. Flushing these radiators will only cause you to add more water to the system, which will...

  • Where does the air vent belong on a cast-iron steam radiator?

    If it’s a one-pipe steam radiator, the vent belongs on the side of the radiator that’s opposite the pipe. Because the lighter-than-air steam will head first for the top of the radiator, you...

  • Does a two-pipe steam radiator have to have a steam trap?

    No, but it has to have something to keep the steam from entering the condensate return lines. That “something” may be an internal orifice, a tiny check valve you can’t see, a hidden...

  • What’s the difference between a steam and a hot water radiator?

    It’s the way the radiator sections go together. They may be nippled together at both the top and bottom, or just at the bottom. Older steam radiators have nipples across just the bottom portion...

  • The best place to install a cast-iron radiator

    *Q: If I decide to move a cast-iron radiator, where should I reinstall it?* *A:* Ideally, a cast-iron radiator should be under the window (that’s where the greatest heat loss is), and it should...

  • What’s the best way to disconnect, move, and reconnect radiators for floor repairs?

    First, take care with those old pipes. Make sure you’re using two wrenches when you’re loosening the union connections. Assume the position, and then turn one wrench while holding back with the other....

  • Can I successfully cut down the size of an antique cast-iron radiator?

    Maybe. It all depends on how the long-gone manufacturer assembled the radiator. A cast-iron radiator goes together in sections, like a loaf of sliced bread. Each section attaches to the next with round...

  • Rethinking TRVs for Steam Systems

    *In 1992, I wrote a book called, The Lost Art of Steam Heating. I did okay with that one. People still buy it.*             I have a section in there about using thermostatic...

  • Tips on Steam Heating Systems

    Dan Foley shares expert tips from his work with steam heating systems.

  • Best WiFi Thermostat for Steam Heating?

    *A question asked on The Wall:* *What WiFi Thermostats work best for steam?* Hi, guys. Im getting lots of requests for wifi thermostats. Which ones work well with steam? I can't seem to glean that info from...

  • How to Remove an Old, Threaded Fitting Video

    A Wallie, *Bio*, posted this video as a part of a great thread that *Delta T*, another Wallie, started. He posted: Thought I would share this trick for getting an old threaded fitting...

  • Cast-Iron Radiator Restoration: Removing old pipe nipple to make way for new fittings Video

    Bob "Hot Rod" Rohr of Caleffi shows how to remove an old pipe nipple to make way for new fittings when restoring a radiator.

  • Foaming and Priming in Steam Boilers

    *Dry steam is steam with very little liquid water in it. For heating systems, the goal has always been to have 98%-quality steam leaving the boiler*. This means that there's not more than...

  • Dan Holohan's Dead Men's Steam School Seminar Video

      Here is an excerpt from Dan Holohan's Dead Men's Steam School Seminar. *Click here to purchase this course.* This all-technical, three-hour-and-18-minute video seminar will make you familiar with the many types of old...

  • How to Fix a Leaky Cast-iron Radiator

    J-B Weld Company of Sulfur Springs, TX (903-885-7696) told me that the City of Dallas, Texas used their product to repair a cracked Caterpillar engine block. That sure got my attention! They also...

  • How to Size a Boiler-Feed Pump

    *When it comes to boiler-feed pumps, the two important variables are the amount of water in the operating range of the boiler, and the steam-to-condensate time lag across the system.*             The operating range...

  • Discovering Water Hammer

    *Discovering that water hammer has moved into any hydronic system, be it steam or hot water is never fun, but finding the cause of it sure can be. Hey, you get to...

  • Steam Boilers for Breweries

    Here are some excerpts from my new book, *Lessons Learned: Brewing with Steam*. I wrote it to help you design, install, and maintain steam systems used in the craft brewing and distilling business. Craft...

  • Radiator colors

    Ever wonder why so many of the old radiators you see are painted silver? Back in the day, they were mostly plain grey metal, but then the Spanish Influenza arrived during the winter...

  • Old Radiator Ratings

    If you're replacing a steam boiler, there's only one right way to size that boiler, and that's to measure the radiators. If you're replacing a hot-water boiler, you'll do a heat-loss calculation on the...

  • Low-Pressure Steam vs. High-Pressure Steam

    Low-pressure steam travels faster than high-pressure steam. Here's why.

  • “Vacuum Boost” for steam heating system pdf

    Igor Zhadanovsky is one of the brightest people I have ever met. This paper is one you should read if you're involved with buildings that have steam heat, regardless of the age of...

  • Balancing Steam Systems Using a Vent Capacity Chart pdf

    This booklet is the work of Gerry Gill and Steve Pajek, two very knowledgeable contractors from Ohio. You can learn more about them HERE. Gerry and Steve did this exhaustive, original research on...

  • What is a thermostatic radiator valve?

    A thermostatic radiator valve enables you to control the temperature of that specific radiator, thus giving you greater control of the temperature and comfort of that room or space.

  • Boiler Replacement: Always Question the Existing Piping

    Here’s a war story for you. I stood with a guy in the basement of a small commercial building on Long Island a few winters back. Several weeks earlier he’d attached a brand-new...

  • A New Look At Vacuum Heating

    Igor converts a steam heating system to a vacuum system in this unique retrofit.

  • Why steam boilers short-cycle

    Wander and wonder. If you were air, could you get out? Answer that question and you’ll cure just about every short-cycling burner problem you’ll ever meet.

  • The Dangers of Raising the Water Line

    Like near-boiler piping, you have to consider low-water cutoffs and automatic water feeders a part of the boiler nowadays. Install them where the manufacturer tells you to install them. If you have to submerge a tankless coil in the summertime, do it by hand. There’s no way around that. Steam heat is strictly a hands-on proposition.

  • Steam radiators make a popping noise. What to do?

    A visitor to the Wall asks, "I'm getting expansion noises from a cast-iron radiator and trying to figure out where it coming from." "Maybe the pipe that comes through the floor is hitting wood?...

  • Steam boiler water-feed issue Video

    Gerry Gill is brilliant when it comes to solving steam- and hot-water-heating problems. Learn more about him HERE.  

  • Mouat water-seal explanation Video

    Gerry Gill is brilliant when it comes to solving steam- and hot-water-heating problems. Learn more about him HERE.

  • Air locking of a two-pipe steam system Video

    Gerry Gill is brilliant when it comes to solving steam- and hot-water-heating problems. Learn more about him HERE. 

  • Testing of the Mepco Main Steam Vent Video

    Gerry Gill is brilliant when it comes to solving steam- and hot-water-heating problems. Learn more about him HERE. Gerry is co-author of Balance Steam Using a Vent-Capacity Chart, which is some of the...

  • Hybrid cast iron radiator on steam mini-tube Video

    Gerry Gill is brilliant when it comes to solving steam- and hot-water-heating problems. Learn more about him HERE.

  • Steam mini-tube general overview Video

    Gerry Gill is brilliant when it comes to solving steam- and hot-water-heating problems. Learn more about him HERE.

  • Washing Out a Steam Boiler Video

    Gerry Gill is brilliant when it comes to solving steam- and hot-water-heating problems. Learn more about him *HERE*. 

  • Steam unit heaters can present a challenge

    They built the place in the 1930s and heated it with steam. It's always been a commercial building - part office, part factory. They heat the offices with one-pipe steam radiators and the factory...

  • How they piped coal-fired steam systems.

    The basement was as musty as a used bookstore and the shadows thrown by the single 100-watt light bulb hung like old clothes against the walls. I felt as though I'd walked back...

  • How They Rated Radiators

    So go look in a radiator catalog and you’ll see the EDR (that’s Equivalent Direct Radiation) ratings for all those different shapes and sizes. We take those numbers for granted nowadays, but believe...

  • What do to with boilers during the summer

    I read dead people. Not many people graduate from Harvard at the age of 20 but Theodore Minot (who, understandably, went by T.M.) Clark did. Mr. Clark was born in Boston in 1845,...

  • A Steam Heating Primer

    If you ask a dozen people what the proper operating pressure for a steam system is, you'll probably get a dozen different answers. Most folks just follow "what they were taught"without giving much thought...

  • What causes water hammer? And how do you stop it?

    Looking for ways to stop water hammer in your steam heating system? Here is a list of common causes for water hammer and how to prevent noisy pipes.

  • Reasons why you can't raise pressure on the gauge, and where to look for solutions

    You're looking for more pressure than you need. It doesn't take much pressure to heat a building. The Dead Men sized their pipes so that the steam would create a very slight pressure...

  • Reasons why there's too much heat in the building, and where to look for solutions

    The radiators are too big for the space they serve. There once was a time when people were afraid of the air in a closed room. They thought "vitiated" air (the name...

  • Reasons why there's no heat in certain parts of the building, and where to look for solutions

    The steam traps have failed in the closed position. If a thermostatic radiator trap fails in the closed position, no air will pass through it, so little or no steam will arrive at...

  • Reasons why there's a bad odor coming from the system, and where to look for solutions

    The one-pipe steam system has an odor. One reason the Dead Men invented two-pipe steam at the turn of the century was to get rid of the odor that often wafted out of...

  • Reasons why the water is bouncing in the gauge glass, and where to look for solutions

    The boiler is priming or foaming. Priming is the violent bouncing of the water. Foaming happens when bubbles form on the surface of the water. Foaming follows priming, and while priming is bad,...

  • Reasons why the system takes a long time to heat, and where to look for solutions

    The system doesn't have main vents. Steam will always follow the path of least resistance. Since it's a gas, it doesn't understand the difference between up and down. All it knows is OUT!...

  • Reasons why the system is producing unwanted vacuum, and where to look for solutions

    There are sags in the mains between the boiler and the main vents. Sags in the main give condensate a place to lay. This creates water hammer when the system starts again, but...

  • Reasons why the system is losing water (that doesn't return), and where to look for solutions

    You can't see all the pipes. If you can't see them, suspect them. This is especially true of buried lines. Condensate contains a mild solution of carbonic acid that can eat through steel....

  • Reasons why the return lines are clogged, and where to look for solutions

    The system is corroding. All steam systems are open to the atmosphere. Whenever you mix water with iron and steel you're going to get rust, and that rust is going to wash down...

  • Reasons why the radiators don't heat all the way across, and where to look for solutions

    Are you sure they're supposed to? Keep in mind the Dead Men sized those radiators to heat the room to a comfortable temperature on the coldest day of the year. That's the day...

  • Reasons why there's too much water in the pipes, and where to look for solutions

    Steam and condensate flow in the same direction, and the pitch is less than one-inch in 20 feet. There should be no areas where condensate can gather when the system shuts down. If...

  • Reasons why the fuel bills are abnormally high, and where to look for solutions

    The air vents aren't working. And if they're not, the system will trap air and drive the fuel bills up. Steam and air are both gases, but steam is lighter than air so...

  • Reasons why the condensate- or boiler-feed pump is misbehaving, and where to look for solutions

    The strainer is clogged. There should be a wye or a basket strainer on the inlet to the condensate pump. This strainer's job is to collect sediment from the system before it can...

  • Reasons why the burner shuts off on low water, and where to look for solutions

    The system is leaking. Do you have buried return lines? If so, they may be leaking. Are your air vents in good condition? You can lose plenty of water through a leaky air...

  • Reasons why the burner short-cycles, and where to look for solutions

    The thermostat is out of calibration. If it is, the burner will be bouncing on and off. Make sure you use an ammeter when you're checking the calibration. Don't guess at that anticipator's...

  • Reasons why the boiler water is dirty, and where to look for solutions

    You may be asking for too much. Since a steam system is open to the atmosphere and constantly rusting and corroding, it's very difficult to keep the water pure. You should always expect...

  • Reasons why steam boilers flood, and where to look for solutions

    The boiler's water line is surging. Dirty water, a too-high pH, overfiring and improper near-boiler piping can all cause the boiler's water line to surge up and down. If there's an automatic water...

  • F&T trap lessons

    I learned these things the hard way. It took me a while. *1) The Only Time You Need F&T Traps Is When You Have A Condensate Pump Or Dry Return Lines.* F&T traps...

  • The $37 million steam trap

    Here’s to preventative maintenance, a practice often overlooked. When the laws of physics and the laws of economics collide, the laws of economics nearly always win in the short run, and especially in...

  • Steam Traps Trap Steam

    One of the things I loved about this business when I was first coming up was that the name of a component nearly always defined its function. All I had to do...

  • How NOT to size steam traps

    I was in the basement of this six-story apartment building in a suburb just north of New York City. This goes back some years when I was working for a manufacturers' representative. We...

  • The 25 steps in the repair of a vacuum steam system

    *1.* Long ago, a Dead Man decided to heat a big building with a steam system. Since it was such a big building, and since pipe, valves and fittings have never been...

  • A bit about vacuum pumps

    Steam systems that make vacuum with pumps have been around for more than 100 years. In 1899, D.F. Morgan wrote an article in The Metal Worker magazine, suggesting that designers skip the pump...

  • The importance of pH in steam-boiler water

    What’s the cheapest tool you can carry if your business includes taming old steam-heating systems and making them purr with greater efficiency? Litmus paper! You probably learned about the power of hydrogen in grade school....

  • Two-Pipe, Air-Vent Steam Heating

    The building was on Fifth Avenue in midtown-Manhattan, and that’s one of the reasons why this one has stayed with me for so long. It was so stately and classy. It stood...

  • Zoning Steam Systems

    A gravity-return steam system uses a combination of two forces to put the returning condensate back into the boiler. First, there’s the steam pressure that's leftover at the end of the mains. Now,...

  • Water Hammer in Steam Heating Systems

    Need to get rid of the water hammer in a steam heating system? Here's a checklist of things to look for. I hope you find it a good one to keep on...

  • Best thermostats for steam systems

    Someone on The Wall asks, "What is the best thermostat for a steam system?" *Bill Wolfe replies:* First, a couple questions. Do you have central AC? Is the house vacant during work/school hours? Are...

  • What I've learned about steam pressure

    It had stood on this corner just off Wall Street in Manhattan for nearly a century. It stood witness to the comings and goings of countless people who never gave much thought to...

  • Steam velocity

    One of the things I had to get through my thick skull when I was young and learning about steam heat was that raising the pressuretrol setting wasn't going to get the...

  • Steam piping and pressure differential

    A New York City contractor called me a last winter to tell me about a situation that he had gotten himself into. We’ll call him Augie because that’s close enough. "The old steam...

  • Why you should insulate steam pipes

    When you take an old house under your wing you sometimes also get to take possession of an old steam heating system and an awful lot of asbestos insulation that goes along...

  • How vacuum can form in a steam system

    I heard from an old friend the other day. This guy works in Brooklyn, NY, and usually on some very interesting stuff. He's not one to say fuggedaboutit when there's a problem...

  • What you should know about the Hartford Loop

    A Hartford Loop is an arrangement of piping between a steam boiler’s header and its gravity-return piping. The end of the header drops vertically below the boiler’s waterline and connects into the bottom...

  • The importance of near-boiler piping in a steam system

    Years ago, steam heating was a business of installing complete systems and not just a business of replacing boilers and fixing problems, as it is today. Manufacturers made boilers that could produce dry...

  • Why Do Steam Coils Freeze?

    This e-mail showed up in my inbox one day. "Our problem is that five out of hundreds of univentilator coils freeze up on a regular basis. They are part of two pipe steam...

  • What is a Drop Header?

    A question asked on The Wall: "What's the point of building a drop header for a steam boiler, and what does it look like?" *Steamhead replies: * The drop header keeps water from getting...

  • How to flush the return lines on an old steam system

    Some suggestions from contractors who post on The Wall: We use newspaper,red rosin paper and kitty litter. We are as careful as possible, but spills do happen. Because we know this, we...

  • Flooded Steam System Caused by Poor Piping

    Always ask, "What can cause this?" I once looked at a house in New Jersey where the first-floor ceiling had caved in due to a disagreement with the steam system. This was a...

  • Copper tubing and steam systems

    A question asked on The Wall: "Is it okay to use copper on steam systems?" *Brad White replies: * It is not so much temperature as cyclical heating and cooling. Hot water runs at...

  • Balancing One-Pipe Steam Systems

    One of biggest challenges in working with vintage heating systems is to put them into balance so that everyone is comfortable. This is especially true when it comes to one-pipe steam since most...

  • Noises follow a steam-to-water conversion

    Trane whistles He had converted this old steam system to hot water and now he couldn't get paid because the system was whistling. "What do you mean by whistling?" I asked. "It's making that...

  • Why water might leave a steam boiler

    I was once on a problem steam job where the water seemed to vanish from the boiler as soon as the pressure hit its high pressure and the burner shut off. There...

  • Why undersized steam boilers waste fuel

    A guy called me to ask if I had any output ratings for some oddball steam radiators he needed to measure before he could replace the boiler. I looked them up and...

  • Taking Another Look at Steam Boiler Sizing Methods

    Due to the efforts of many sharp minds in the steam heating industry and simple economics, standing cast iron steam space heating systems are no longer wastefully being thrown away like last years...

  • Steam boilers in food-processing applications

    Billy was having a bad day. Mario the Baker had called him first thing that morning to say he was going to drive to Billy’s office and punch him in the face....

  • Steam boiler-room tips

    Old boiler rooms often are home to steam-heating boilers. Our older cities are loaded with these, and lots of people (knuckleheads included) have had decades to mess with what the Dead Men once...

  • What makes a steam boiler fail?

    I started my career in the heating industry in 1970, when I was 20 years old. I was fresh out of college and my number in the Draft Lottery that year was...

  • Modular steam boilers

    Modular steam boiler systems can look very attractive when it comes time to replace an old steam-heating boiler. The people who sell these systems promise ease of installation and energy savings. But how...

  • How to replace an old steam-heating boiler

    Here are some good tips for you. *Base the size of the replacement boiler on the connected load, not the building’s heat loss*. The boiler’s ability to produce steam must match the system’s...

  • Why you can't use high-pressure steam boilers on low-pressure steam systems

    This was going to be an easy job – one of those in-and-out deals where a guy can make a fast buck, but the truth was he didn't really care whether he...

  • The importance of air venting in steam systems

    Where there is air, steam will not go. Years ago, in some dank basement, a contractor installed a large air vent near the end of a steam main. He did this because he...

  • Thermostatic radiator valves

    What's wrong with this picture? See the remote thermostat sitting on top of the hot radiator? The folks in that office wondered why they couldn't seem to get comfortable. You can't make this stuff...

  • Steam vs. Hot Water

    It was a real battle in the early days of heating. There were steamfitters and then there were the hot water people. I have a wonderful old ad from Honeywell that goes...

  • Why your boiler needs a low-water cutoff

    A friend of mine who happens to be a contractor went out to look at a hot water boiler that was causing its owner a problem a few years back. It seems...

  • How can cavity-wall insulation help your home remain heated?

    Keeping your home heated is about more than just having a source of heating, as it also has a lot to do with preventing heat from escaping the interior of your house. This...

  • Insulate your home and get energy efficient

    The cost of heating and running our homes on electricity and gas continues to increase. With the amount of money being spent by millions of families every year, it’s important to make sure...

  • Bubble-foil insulation

    On this subject, I'll direct you to Robert Bean's HealthyHeating.com site, where he makes his case very well. 

  • Best insulation tips

    In the autumn, of the block of flats in which I live (I’m not posh enough to live in an apartment) I had cavity wall insulation installed. What followed a few months...

  • A heat-friendly house - simple tips to improve insulation

    Now that the price of heating a house has gone completely through the roof, homeowners have to be far better at saving energy than they used to be. Gone are the days...

  • Indoor Air Quality and Tight Houses

    Good IAQ starts with a tight building. It is often said a house has tobreathe. This brings to mind a Prohibition-era movie where one gang has captured members of their rival. Lined up...

  • Basics of Indoor Air Quality

    We of the Hydronic Realm often don't think too much about Indoor Air Quality, but that mindset is obsolete. We need to look at the Big Picture, not just the heating system. We...

  • Converting from steam to hot water heat?

    First things first. Before the 1920s, most steam contractors used cast-iron, column-type radiators. Those are the free-standing ones with the real wide sections. Column radiators were perfect for steam heating because they had...

  • How to run a hot-water zone off a steam boiler

    *Q: Is it possible for me to use the condensate in a steam boiler to make a hot water zone? * A: Sure! Heating professionals have been doing this for years in areas...

  • Gas-Pipe Sizing Chart pdf

    Which is just that! 

  • Using vacuum gauges to tune an oil burner

    Vacuum Gauges Paint a Picture for You By painting a picture I simply mean that when you use this instrument it will reveal some much needed information when diagnosing a fuel related service...

  • Why Do I Need a Chimney Liner?

    There are several reasons why installing a stainless steel, flexible chimney liner is important. The primary reasons are to ensure the safety of your home and to maximize the efficiency of your heating...

  • Is Chimney Liner Insulation a Must?

    Here’s the quick run-down on insulating your chimney. Insulating your stainless steel chimney liner is highly recommended. Chimney liner insulation helps ensure safety and efficiency of the chimney. Insulation allows for the flue to...

  • Choosing the Right Chimney Liner for Your Application

    Your current chimney flue may be showing signs of deterioration, such as a hairline crack in the flue, missing mortar between the clay flue tiles, or you may not have a flue at...

  • Boiler Ratings Explained

    When you look in a boiler manufacturer's catalog you'll see that there are several types of ratings for each boiler. There's the Input rating, the Gross Output rating (which some call the D.O.E....

  • Thermocouple Testing Procedure

    I am often asked about troubleshooting a thermocouple on gas systems. This will be a permanent reference that will give a step-by-step procedure: A thermocouple is a device used to satisfy pilot safety...

  • How to have a boiler replaced

    "We haven't had decent heat since that heating contractor left our basement."  She was about as angry as any homeowner who had ever called me. "We paid good money for that new boiler,"...

  • How that steam boiler got to be so big

    There was a time in America when people were afraid of the air that they found inside their homes, and with good reason. Many of these people lived in tenements, and they were...

  • Boiler Sizing

    When steam heating was new, back at the turn of the 19th century, coal was the fuel of choice. It burned hot, and it burned long. A good coal-fired boiler would stay lit...

  • Steam Boiler Near-Boiler Piping Video Video

    All of these pipes around the steam boiler are important. Don't settle for less than what I'm showing you in this video. - Dan Holohan