What were the 2 main problems of the valves in the colossus?

The two main problems with the valves in the Colossus were their tendency to stick and their susceptibility to overheating. The design of the valves made them prone to mechanical failures, which could lead to reduced performance and reliability in the machine. Additionally, the high temperatures generated during operation exacerbated these issues, further impacting the overall functionality of the Colossus.