Price is to replace the internal check valve for Rinnai tankless water heater. Cautioned customer that this is a next step, and if issue persist additional diagnostics and possibly repairs will be necessary. Returned and installed customer supplied faucet and replaced the internal check valve for the tankless water heater. Noted to customer when checking that there still appears to be a cross connection from hot to cold. Isolated the only two single handle fixture in the home and cross was still occurring. Had noted heavy pitting and deteriorating on the brass parts internally for the water heater. This is likely due 5 years of the tankless not being serviced, as well as additional sediment incoming from the galvanized line. Additional repairs on the tankless aren’t recommended due to poor conditioning on the unit and the likelihood of causing additional issues or additional leaks. Tested new faucet and it is functioning properly. Will follow up with customer next week to discuss wate
