Sam replaced our hot water service in the roof and sum plumbers said that you can't have these anymore. Sam explained that any hot water service under the main roof can be changed. We nearly had a hart attack when one of the plumbers that came said we have to have a heat pump unit installed at a cost of 5 grand. Sam changed our roof unit for 1650. We did not have 5 grand for hot water. Sam said that our new unit will last 20 years.thanks Sam for your help