Pride Plumbing was called out for lukewarm water from a Navien 240A2 tankless water heater. Our inspection and tests determined that the issue was being caused by low water pressure - the gallons per minute (GPM) flow rate was too low and not allowing the tankless to call for hot water. We made an adjustment to a pressure reducing valve (PRV) at the water heater, performed our tests again, and the water temperature issue was corrected.