SIMPLE - Navien tankless FLOW SENSOR replacement -- 10 minute job

Navien tankless hot water heater flow sensor replacement. You won't believe how easy this is. Most plumbers around here will charge $200 for this 10 minute job. Maybe more because they'll have to do hours of troubleshooting and come back 3 times. If this doesn't work for you try flushing your system with vinegar. That should be your first step.