There is minimal maintenance to keep the water heater running good as new. Here is a quick link to some helpful steps http://www.wikihow.com/Maintain-a-Tankless-Water-Heater
Oftentimes the attic is the place to start. Make sure you have plenty of ventilation, both intake and exhaust. Check the soffit cavity to make sure you it isn't clogged with insulation. There are f ... read more