TAMING YOUR STEAM SYSTEM – THE “HARTFORD LOOP” AND EQUALIZER PIPING

In our preceding blog we addressed the subject “Plumbing Guys Plumb, Heating Guys Heat” to emphasize the need to employ complimentary skills in heating installations.

Ironically, within a week of publishing we received a call from a new client complaining of “loud banging and water spurting out of the radiators” in a home they were to rent. A complimentary assessment and surprise followed that prompts this follow-up article.

Apparently ten years ago a new, small, but adequate “plumber’s” steam boiler was installed to replace the original, large coal or wood boiler in the old farmhouse. The plumber exhibited good workmanship in “stretching the pipes” using copper and fittings to connect the new boiler, but obviously had no comprehension of steam heating, didn’t refer to the supplied Installation Manual requirements — or both. Explanation.

Old Steam Heating Systems featured large water capacity boilers likely originally fired by coal, wood, etc. and necessitated by the continuous, lower temperature fires they utilized. The radiators, properly sized and positioned, provided nice, efficient, humidified and comfortable heating with that little hiss of venting steam. These boilers however were terribly inefficient, requiring firing attendance and water replenishment while consuming large quantities of cheap fuel.

Conversely, new high-efficiency, intermittent and higher temperature fired (gas or oil) boilers are necessarily much smaller to provide the same output. Therein lies the problem. A ten-gallon boiler now replaces a fifty-gallon unit. All this size and water dampened and regulated the steam output of the “Old Dragons”. Now control has to be introduced to compliment these smaller “steamers”. (Also see our “Upgrading Your Steamer” Blog.)

Every Steam Boiler Manufacturer in his “Installation Instructions” Manual details a boiler piping configuration known as “The Hartford Loop” and Equalizer Piping, whether so-called or not. Named after the Hartford Insurance Company that funded its development, it tames the modern steamers by preventing the overheated, split and sometimes exploding boilers resulting. Rather than expounding upon the Hartford Loop and Equalizer we refer you to an excellent article on MasterPlumbers.com entitled “What you should know about Hartford Loops” by Dan Holohan. It is well written and thorough.

Now back to our misbehaving steamer. Walking into the home, it sounded like “The Anvil Chorus” being played by atonal blacksmiths with three-pound hammers both in the basement and on the radiators. Hot water spewed out of all the radiator steam vents even to the second level and all the floors were subsequently blackened by stains near them. Downstairs the boiler was surging steam internally, forcing condensate (hot water) up the supply pipes and back-flushing into the returns. Flash evaporation caused by driving steam through hot water created a cacophony of sonic noise throughout the basement. No water level was detectable in the boiler sight glass. The automatic water feeder and low water detector had apparently been fooled (thankfully) into overfilling and nearly flooding the boiler. This is the only thing that has saved this boiler (thus far) from destruction. (These sleepless tenants are the third in the past six months in this place — can’t imagine why!)

This is undoubtedly the worst plumber-error installation we have seen to date. Most are more subtle with lesser impacts. It serves though to emphasize that utilizing appropriate resources is paramount to successful and ultimately safe heating system installation and operation.

Steam system questions seem to predominate in our inquiries. There obviously is a deficiency of skills and understanding of steam heating, even within the heating trade itself. Hydronic (FHW) Heating has long ago overtaken Steam as a heating medium, whether wholly justified or not.

Specifically addressing your steam heating system installation and operation, question the aggravations that may arise such as noise, water consumption, piping leaks, heating uniformity and fuel consumption. Anything beyond warm, comfortable heating with that little hiss from the radiators is abnormal. Enjoy your steam heating benefits!


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