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2 Pipe Return vs. Monoflow

My wife and I recently installed a new Navien Combi Condensing boiler which replaced the old boiler AND water heater.  The original radiant heat system in the house is a monoflow (single pipe) system.  The installers put in a primary loop which the supply loop receives it's water from.  The house heats just fine, but I'm wondering, from an energy savings standpoint if a 2 pipe return system is more efficient or if it doesn't really make a difference.


  • kcopp
    kcopp Member Posts: 4,262
    With that type....

    of a boiler it is really your best option. Running directly out to the system and back through the boiler is not a good plan. The boiler would not work right. Flow is everything and your flow is restricted w/ the diverter tees.
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