Hartford loops, banging pipes, and leaky valves


    we recently had our oil boiler serviced by our fuel-oil company. they left us a note saying that the “hartford loop” is too high, which apparently can result in radiator banging, boiler flooding, and water leaking from air valves. (this is our first winter in the house using this boiler.)

    over the last few weeks, our pipes/radiators do indeed make banging sounds; there are frequent and very loud hisses from the valves; and one radiator sometimes leaks/sprays water from its valve.

    i’d appreciate recommendations for a plumber who can do a full audit of our system and fix these issues relatively quickly. it should be someone who can deal with oil boilers (a couple of the mainstays on this site i called only service gas boilers). thanks in advance for any advice you can provide!

    2 Replies

    1. hi there – its my understanding that radiators should be pitched toward the valve ie shimming up the vent side so when it cools off the condensed vapor drains out of the radiator. if it doesn’t drain it collects and may cause spurting or leaking through the vent. banging can also be the result of improper pitch in a heating system – usually water getting trapped in elbows etc..

    2. Z, I’m trying to think of a condition that would be created by a too-high Hartford Loop that would result in radiator banging and hissing.

      I’m coming up with very little except if the radiators in question are all on the next floor above the boiler and the horizontal boiler mains are set very low.

      I’m willing to bet you’ve got an excessive pressure thing going on.