Rinnai heater parts can be found online at Sears Parts Direct or HouseNeeds.com, as of 2015. Both sites have an easy-to-search interface and the ability to view details about a particular part.
When ordering from HouseNeeds.com, individuals can find parts for a Rinnai heater listed, but the site does not allow users to narrow down search results. When buying from Sears Parts Direct, however, a buyer can use a diagram to find the exact part needed. There are also manuals to look at, along with an expert question and answer section that may help with repairs. Sears Parts Direct also has a chat feature where questions about the products are answered.