Hoffman Equalizer Loop

Equalizer loop?

I've heard of a Hoffman Differential Loop -- in fact, the system I maintain has one -- but not an Equalizer Loop?



It sounds to me as though you may have had some repiping done in the past, which may have left little evidence.  The Hoffman Differential Loop system did have an equalizer pipe, in the usual way.  The Differential Loop was connected to the dry return (all dry returns merged into one at the boiler), and there was -- and should still be -- a good sized vent right there as well; that was the only vent as such in such a system.  It also tied into the header or riser, and by another pipe into the wet returns.  Sounds more complicated than it is... you might want to take a look at http://www.heatinghelp.com/files/articles/1662/Hoffman%20Heating%20Equipment.pdf -- look on page 12 for a nice explanation of the system.



There is no real harm to taking a Differential Loop out, so long as you have a vapourstat or some other way to control the pressure to less than 12 ounces or so.  Otherwise, if this really was a Hoffman equipped system, you may find that water backs out of the boiler into some of the dry returns, which is not happy. 



In this instance, where it sounds as though the dry returns may have been repiped at some point and don't all join together, you might be better off to repipe the new boiler fully conventionally, and use a vapourstat for control.

See Ed?

I told you Steamhead or Gerry would have the answer!