If you need tankless water heater repair, replacement or installation in Prescott Valley, AZ, Goettl's High Desert Mechanical is here to help. If your tankless water heater isn’t working, basic tasks like doing dishes or laundry can be more difficult. Maybe the water never gets hot, or the temperature keeps changing while you’re using it. Some units shut off in the middle of a shower or display error codes that won’t clear. Hard water buildup, sensor failures, and gas or electrical issues can all cause these problems.