Was tired of running out of hot water so I installed a new NPE-240A2 (w/ a Watts OneFlow filter in series prior to the Navien to help keep the unit clean). Original intent was to keep the nearly new 75 gal tank heater to use as a pre-warmer in the coldest months, but bypass and drain it most of the time. When completed and placed into operation though, the output pressure was terrible. Re-plumbed the system to have the tankless backfill the tanked heater to provide an endless supply of hot water. Less efficient, but was willing to eat that cost. Initially, seemed to be working. However, over the last few weeks it’s become apparent this just masked the issue. If more than one shower head is used, pressure still drops excessively.
Got a manometer today and tried testing the gas flow to see if that could be the issue. I can’t even perform the test because when I open multiple high-flow faucets they just trickle and the tankless simply will not increase flow rate beyond 1.4 gpm, no matter how high the demand on the system. I haven’t found any answers online so I’m hopeful you fellas (or ladies) have ideas.
Got a manometer today and tried testing the gas flow to see if that could be the issue. I can’t even perform the test because when I open multiple high-flow faucets they just trickle and the tankless simply will not increase flow rate beyond 1.4 gpm, no matter how high the demand on the system. I haven’t found any answers online so I’m hopeful you fellas (or ladies) have ideas.
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