Has anyone worked with Fix and Flow Plumbing for tankless water heater service?

Yes! We used them last summer for our tankless install. They were super knowledgeable about all the different brands - Navien, Rinnai, Rheem, you name it. They walked us through the pros and cons of each and gave us a recommendation based on our usage and budget. It wasn't pushy at all, just honest advice. The install was clean and they explained everything. Highly recommend.

I'll second that. I had them service my existing tankless unit. The tech was able to diagnose a weird error code that two other companies couldn't figure out. They actually knew the specific brand and model quirks. Fixed it on the spot. Two thumbs up from me.