One of our oil tanks was moist at the bottom with a tiny tiny leak. No drips yet and the moist area looked the same for years. We had a change at Heat USA and SOS became our oil provider. SOS said because of the leak I could no longer receive oil deliveries until I had new tanks installed. I asked them to do it as they had the best quote. They knew how low my oil tanks were. The new tanks arrived late, why? I don't know, and we went without heat for four days in cold weather. If the tanks were on time it would have been 5 stars, the people at SOS did an excellent installation.