Rheem 27 & Rheem Metro Max 26 Review vs the Rinnai 26 & B26 Straight off the bat they are both manufactured by excellent companies with fantastic follow up service. I can not say a bad word about either Rheem or Rinnai when it comes to their support surrounding a warranty issue.All of my experiences have been very pleasant even though after installing hundreds of both the Rinnai and Rheem hot water systems I have only had a few minor issues. Such as a Rinnai Infinity had the internal fan which was making a noise and just needed to be realigned. Small issue. Rheem 27 had a wire that was loose and Rheem sorted this out quick sticks.