Hi folks, many years ago I installed a 36 tube system that I bought on eBay. It worked really well for perhaps 8 years when the controller box burned out. I contacted the company that I bought the system from and they sent me a new box. I wasnt able to install this myself due to an injury at that time so I got a local spark to do it. He added another box which I believe is also a controller. The first controller has temp sensors from the manifold and top and bottom of the tank. There is a cable coming from this controller into the panel at the pump setup. The second controller has two temp sensors connected to it but not inserted into the probe ports in the tank. I think that the black cable comes from the manifold also. There is a power lead coming from the second controller which feeds the pump. 

Recently the pump is not being activated by the second controller so no circulation is taking place and, therefore, no hot water being produced.

Am I correct in thinking that I actually do not need this second controller and that the first one should do all I need, as it did in the first place? 

Thanks in advance.