System won’t heat. I found this was do to the unit not being wired properly which made it so that the unit would never call for heat. I corrected control wiring issues and tested the heat the heaters did come on but didn’t at first and didn’t seem to be working well. I recommended we replace the entire heat section as it is pretty old. We will need to order this and return to replace it. I also notice a significant amount of biological growth on the coil and in the unit. I would recommend addressing this as soon as possible I have provided estimates to remedy this.