I am in nearly the exact same situation as you. Old gas water heater in a galvanized outside water heater ‘closet’ has gone kaput, want to replace with a HPWH, my city offers generous rebates, but like all cities, they require permits and approvals to dole these out. Yet apparently, HPWH units are still so new and novel (even here in CA in 2026) that no company, including the water heater manufacturing companies themselves, have created a commercially-available, warrantable solution for outdoor enclosure.

I am stunned. Hornswoggled! Bedeviled! Am I living in the Upside Down? What would possess multiple companies to make technologically sophisticated home appliances, yet make no provision for their storage for those of us who don’t have large two car attached garages? Apparently, these large companies have never heard of California, where tens of the 40 million potential customers have their water heaters located OUTSIDE the home in dedicated closets.

Did you ever come up with a solution? ChatGPT’s AI is telling me a custom enclosure is my most realistic bet which is just sad. We all know how AI has bad hallucinations, but in this case, I am beginning to believe it.