The Weil-McLain SlimFit Commercial Condensing Gas Boiler is ideal for retrofits with tight space limitations, and was made to be able to comfortably be wheeled through a standard-width mechanical room doorway to move it where it’s needed. It is durable, reliable and easy to install. It arrives completely assembled and is ready to go out of the box. It is even pre-wired, pre-programmed and tested in the factory.