Hired this firm to install new tankless water heater and though the product seems okay, the service company is anything but. Less than a year after installation I start getting error codes for the CR-180(A) - The error code is E022: which means the thermistor is malfunctioning. This malfunction halts the hot water process. Repeated calls to the install company result in no reply. I have contacted the manufacturer and I await their reply - I will update this post with any progress.