A multiple boiler system using sectional cast-iron boilers has been configured to supply two loads as shown below. A “crossover pipe” is installed in case the flow rate in the primary circuit is different from the flow through the boilers. The boilers are controlled by a multiple boiler controller that senses the water temperature leaving the boilers and upstream of the crossover. Each secondary circuit is connected to the primary circuit using closely spaced tees. There are several piping and control-related errors in this proposed design. Can you spot at least 5 of them?