A homeowner in Michigan sent an email that had me shaking my head, and not for the first time. Listen:
“Our house is heated by a Utica Gas Boiler that was here when we purchased this house. Sitting next to the boiler is a Hoffman boiler-feed pump. The problem we have encountered is that we’ve had to have the pump replaced five times since 1981. We have hard water (with iron) but I am not sure if that is the problem.
“I had a boiler-service company (different from our regular service company) come to examine our system. He seemed very credible. He recommended switching to a Hartford Loop and eliminating the boiler-feed pump. This is something that I would like to seriously consider. When inquiring online, though, the information is sometimes contradictory. One article states that when old boilers were replaced by new boilers, it was necessary to include a boiler feed unit, and a condensate unit. I am assuming that our boiler would be considered a new boiler since it does not contain a large volume of water. I have read some of the information that you have posted. I am trying to get verification that we could indeed have the boiler-feed unit removed if we go with the Hartford Loop. I would greatly appreciate your advice.”
I sighed and called him.
“Do you live in a mansion?”
“Oh no!” he said. “It’s a modest house, just 2,500 square feet. We have three bedrooms and two baths.”
“How many pipes connect to each radiator?”
“Just one. There’s a pipe on the lower side of each radiator and an air vent on the opposite side.”
“You have a one-pipe steam system in a modest house,” I said. “I seriously doubt you need that boiler-feed pump.”
“Are you sure?”
And why I was able to say Yep from my desk 800 miles away involves a story that has affected many homeowners since the 1970s. It goes like this:
Residential steam boilers used to be much larger than hot-water boilers. They had to be because they needed an internal area in which the steam could escape from the surface of the water. They also needed sections that were wider than those you’d find in a modern hot-water boiler. This is because when steam forms it increases in volume by 1,700 times. If those big bubbles didn’t have enough room to move they would cause the boiler’s waterline to surge violently. That would throw water up into the pipes, which led to water hammer, uneven heat, higher-than-normal fuel bills, and miserable customers.
But then the OPEC oil embargo showed up in 1973 and fuel prices soared. Homeowners were staggering under the higher prices, so the government got involved. They wrote laws that mandated boiler manufacturers to meet certain minimum efficiency standards for all heating appliances, and those standards would become even stricter as time went by.
It was difficult for a residential steam boiler of the Steam Era to meet these efficiency standards because they were all built like NFL linemen. Back then, 60% looked pretty good. But those boilers needed to go, so many of the boiler manufacturers decided to take their hot-water boilers and refit them for steam usage. This was a mistake, and it happened because many of the manufacturers’ people making that mistake during the 1970s and 1980s didn’t understand steam systems. In retrospect, this is easy to understand. During the Vietnam War, few young people entered our industry. The old people from the 1950s and 1960s, who had lots of knowledge about steam heating and steam boilers, had few people to teach.
And then they became Dead Men.
All of a sudden, we had these residential steam boilers that contained much less water than the boilers they replaced. Their sections were much narrower, so a lot of the water wound up in the piping.
It was a big problem and the manufacturers corrected it by stopping the madness of trying to get a modern hot-water boiler to act like a steam boiler. They began, after much discussion, to produce actual steam boilers. But this took time, and that’s what people like my frustrated homeowner were dealing with.
Residential steam boilers used to be much larger than hot-water boilers. They had to be because they needed an internal area in which the steam could escape from the surface of the water. They also needed sections that were wider than those you’d find in a modern hot-water boiler.
In my book, “The Lost Art of Steam Heating,” which arrived in 1992, I wrote about modern steam boilers replacing much larger steam boilers that were served on their condensate-return side by condensate pumps. You need a condensate pump if you don’t have enough vertical space between the boiler’s normal waterline and the bottom of the lowest, horizontal steam main. I cautioned my readers that if they see a condensate pump on a job where they were replacing a steam boiler, they should check to see if the new boiler should have a boiler-feed pump instead of the condensate pump. The reason for this is that the condensate pump starts when its receiver fills with water. It doesn’t talk to the boiler. A boiler-feed pump, on the other hand, only starts when the boiler actually needs water. This was (and remains) an issue in big buildings and many contractors took my advice.
But then mistakes were made. A lot of contractors who were doing residential work began to look at boiler-feed pumps as a necessity on every job, which they are not. A 2,500-square-foot house with three bedrooms and two baths that has one-pipe steam heat and has never needed anything other than gravity to get the condensate back into the boiler does not need a boiler-feed pump. That’s why I was able to shout “Yep” from 800 miles away.
I can guarantee you that the contractor who installed the boiler that’s there now did not find either a condensate- or a boiler-feed pump in the basement of that house when he arrived.
And yet he sold them a boiler-feed pump.
Why? Well, maybe he was nervous and didn’t want to get it wrong. And if he could sell them a boiler-feed pump along with a boiler then he would make lots more money, right? Better to put it in now and get paid than find out he needed one later and have a tough time getting paid for it then. Right?
But that tells me the contractor didn’t know much about steam heating.
Yet he took the job anyway, as did so many other contractors of that time.
And here’s why the homeowner who wrote to me had to replace that pump five times since 1981: A boiler-feed pump has an atmospheric vent on its receiver. That means you need steam traps to keep the steam out of the receiver. Those traps belong at the ends of all the steam mains, but you’ll never find them there. You’ll find instead one large Float & Thermostatic trap right at the inlet to the boiler-feed pump’s receiver.
How come? It’s cheaper to do it that way. But it’s always going to be wrong because it creates two situations: First, it turns what was once a gravity wet return into a steam main. And second, it sends very hot condensate and flash steam puking out of that big trap and into the boiler-feed pump’s receiver. That condensate is hot enough to cause the pump, which has very little static pressure at its inlet, to cavitate and fail. So the homeowner has to pay to replace it every few years.
That boiler-feed pump has absolutely no business being in that house. But that’s what happened to many homeowners. Mistakes were made.
Lots of them.