We would love to expand our excellent existing heliocoI by two panels, to go from "85% to 100% coverage" providing additional heating capacity. We are uncertain if it's a good idea since the two new roof mounted panels would have to be routed 50' away from existing system and which is already nine-years old. Some installers are telling us not a good idea, new panels will cause problems and likely leaks with old system due to pressure changes, and follow-up by recommending a completely new system. Other installers are fine with the additional two panels. We look forward to hearing from you!