Honeywell V4073A 3 Port Valve wiring error.

[tismeagain]

Please note my central heating and hot water is working ok at this moment.
I am considering changing my central heating controller from a Honeywell ST699 to a Honeywell ST900C.
I have checked all the wiring against the Sundial Y-Plan wiring Diagram of the ST699.
Everything is correct except that two of the Honeywell V4073A 3 Port Valve wires have been crossed over. The grey goes to 8 of the connection block instead of 7 and the orange goes to 7 instead of 8 on the connection block.
Can anyone please help and explain the error.
Many thanks in advance.

 

[CBW]

As long as it works currently, then it shouldn’t be a problem, it’s just the Grey will be pump and boiler live instead of Orange.

 

[tismeagain]

Thank you for your response CB