We installed a Waterfurnace 3 ton unit in 2009. The unit was in service until 2018 when we sold the home. We had great service from Waterfurnace and the local installer. At about 5 years, the coil was replaced under warranty at no cost to us. Waterfurnace freely admitted that the coil failed due to a manufacturing problem with the coating and they had since started to manufacture their coils to ensure quality. Our house was to be demolished by a developer, so I disconnected the unit and brought it to our new home. Unfortunately, our lot is not suitable for installation of a ground loop or we would still be using the Waterfurnace unit today. User's recommendation: Waterfurnace ground source heat pumps are great products.