We are an install company in ME. We have clients with Sunda solar hot water systems installed in the last 4-5 years that are under warranty and tubes have failed. Sundeaver in VT use to distribute the product but no longer stock it. They say they had problems working with the manuf. I contacted Sunda/Beijing in China. It has been many months and all I have is promises and no replacement tubes. Needless to say I feel horrible for my clients.