Have you fallen out with your neighbour for any reason, and feel the need to have a go at them?
The plume kit is fine, as said above, however, it looks closer than regs permit to the vent, others may disagree.
New build house builders love throwing in Logic ESP 35 boilers, they must get them dirt cheap from Ideal.
Half the time, they're grossly overpowered for the house.
I'd be curious to know why.
I don't see how the orientation of the vessel will affect its performance, given that part of it contains water, and part of it contains air.