Troubleshooting the Cuckoo’s Nest


The steam seminar was to be in North Carolina, which was strange enough, that being the state where most folks only know how to say, “Heat pump, please.” It was also going to be sparsely attended. Oh, and the location was a nasty, windowless, brick-walled basement room in what used to be a hospital, but was now an office building. I immediately looked around for Jack Nicholson and Nurse Ratched. Welcome to the cuckoo’s nest.

“We’re doing it here because the people who own the building are our clients,” the contractor explained. “Not many people in this state want to work on steam heat. We’re hoping you’ll walk around with us after the seminar and look at some of the problems they’re having.”

I looked up at the radiator that was mounted on the ceiling. “Love to,” I said.

The class went well. The contractor had invited his own people, as well as several of the area’s inspectors. The inspectors all admitted they knew absolutely nothing about steam heat but that they inspected it anyway.

“How can you do that?” I asked.

“We look for what the manufacturers tell us is right,” one drawled.

“Which manufacturers?”

“Usually the boiler (he actually said “bowler”) manufacturer.”

“But there’s a system attached to the bowler,” I said.

He nodded. “Yep, that’s the problem.”

I asked the contractor who had hired me about the steam pressure and he told me they were running the boilers at about eight psi.

“Did you know they run the Empire State Building at one-and-a-half psi?” I asked.

“Nothing works if we go under eight pounds,” he said.

“And it works at eight pounds?”

“Well, yes, but then parts of the building get too hot, so the people in the offices open up their windows.”

“And you call that working?” I said.

“Around here? Yep.”

“Is there water hammer?” I asked.

“Do peaches have pits?”

“This building is an annuity for you, isn’t it?”

“No one else will touch it,” he smiled.


That has to be a good situation for a contractor. Especially for one who is willing to learn about older heating systems that, when neglected, behave like a demolition derby. If you can work that system back into the shape it was in when new (that being fast, quiet and efficient), your customers will never go anywhere else. And they will tell everyone they know that you are the best around. And that’s good.

So here’s how to begin:

Look at the near-boiler piping. If water is leaving the boiler with the steam, you’ll never be able to heat the building. The near-boiler piping’s job is to separate the steam from the water and put the water back into the boiler. Get the boiler manufacturer’s specs for that near-boiler piping and compare it to what you see on the job. If the piping is wrong, redo it. That system will never work properly if the piping allows water to follow the steam up into the building.

Watch the pressure. With steam heat, it’s not normal to be running at high pressure unless they’re using the steam for some sort of process, such as cooking food or sterilizing instruments. The highest pressure you will ever need for space heating is two psi. That’s been the rule since 1899 when heating engineers agreed to use steam-pipe-sizing charts that kept the steam’s pressure drop very low as it moved from boiler to radiators. This is how the Empire State Building gets by on such low pressure. It’s not the pressure that heats the people; it’s the latent heat of the steam, and that’s there at zero psi. The only pressure you need is enough to overcome the pressure drop as the steam races through the pipes, and that’s only about one- or two ounces of loss for every 100 feet of travel. You can take this one to the bank. Literally.

Think like air. If you can’t heat the place on low pressure, there’s probably air trapped in the pipes that can’t escape because the air vents are either broken or missing. Steam is lighter than air and the two will not mix. Every steam system starts out filled with air. When the water turns to steam, it expands 1,700 times, and that’s at zero psi. The steam pushes the air ahead of itself like a plunger. If the air can’t get out, the steam stops moving and gives up its heat. If you don’t know this, you’ll be tempted to crank up the pressure. That will just give the steam more power to compress the air. The pipes get hot a bit further out into the system. You may see this as a great thing and raise the pressure even higher. There still won’t be much heat in building, though, because the air still can’t get out. And the burner will be running most of the time. Oh, and the people who are in the building will be opening the windows on the coldest of days. And some folks will think this is normal. It’s not.

Get out of the boiler room. Don’t be a flame head. There’s a big, beautiful system out there beyond that which makes fire. Go wander. Know that the system is filled with air at the start of every steaming cycle. The steam has to push that air out, so start at the boiler and ask this key question: “If I were air, could I get out?” Follow the pipes and keep asking that question. Look for the main vents, or where the main vents used to be before some knucklehead replaced them with pipe plugs. Look, too, for the vent line on the condensate- or boiler-feed pump receiver. When steam traps start to fail, steam will come out of those receiver vents. Did another knucklehead plug that vent line and raise the boiler pressure? That’s when the place really turns into the cuckoo’s nest.

Know the components. If you see something you can’t identify, take a picture of it and post it at If it’s old and strange, you’ll probably also find the factory literature for it there. At Nurse Ratched’s former hospital, the contractor who hired me to do that seminar pointed at an iron shape that had more coats of paint than the Brooklyn Bridge. “What’s that?” he asked and I told him it was a Series 19T heavy-duty steam trap, made by the Webster Company in the 1920s. It was able to handle unusually large amounts of condensate. It wasn’t working, and that was one of the reasons why the system was making more noise than NASCAR.

There’s more to learn, of course, but that short list is a fine place to begin. Not every building is going to have a heat pump, and that’s especially true of older institutional buildings. Get to know those systems and watch how many people beat a path to your door.

It’s good when you can sell what’s in your head, isn’t it?


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