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radiant floor heat in garage
i have a 4 loop 1/2 pex that goes to a manifold, it has a alpha 2 pump and a takagi T-H3M-DV-P Indoor Tankless High Efficiency Condensing Water Heater. my room temp is 53 my inlet temp is 140 return temp of 80. i used 100 gallons of propane in 2 weeks, the pump on high shows a gpm of 2 and pressure of 12 psi..not sure why im using so much fuel. if i shut down 2 zones i can get 1gpm per zone but with all 4 open they show like .4per zone.. any help would be appreciated. building is 1400 sq ft with 12 foot ceilings