What are the clearances to combustible and non-combustible material from the heater? Please refer to the installation manual for your unit to find the appropriate clearances. Updated on April 13, 2021 Tagged: Clearance Was this article helpful? Yes No Related Articles What do I use to run the drip line for the condensation T? Hot Water Supply Capacity How to Install an External Remote What are the clearances to combustibles when using N-Vent? Can I install my heater in a closet/cabinet? Why are the side clearances larger for the new stainless steel models?