I have had a Rinnai R75LS tankless water heater for 9 years. I have not had a single problem with it. Yesterday it read a code 11, went to online manual it read it ignition problem unscrewed the ignition element, cleaned it with a wire brush and it fired right up. I have a family of 4 and we have never run out of hot water. Cost $2000 installed and have never had a service agreement on the unit. It has been cleaned 1 time over its life. I would buy another again, very efficient.