Pacific Palisades, Takagi tankless Water Heaters!

Village Plumbing and Heating was in Pacific Palisades troubleshooting two tankless water heaters. Village Plumbing and Heating was called out for a Takagi TK3 OS-Heater making noise. Checked and found that units both needed to be descaled. Village Plumbing and Heating pulled out the heat Exchanger and flushed with solution to get rid of the build-up. At the other location, they were not getting any hot water. Had over heated and replaced high heat cut off valve. We also descaled the unit.