Panic over. Installer called. Valves were nowhere near boilers; in another room in fact.
All sorted and boilers are merrily doing their thing.
<happy dance>
I'm a stay at home mum. I know NOTHING about boilers, but I've been reading lots of threads as I've worked my way through two glasses of red.
My problem is this: I have no butterfly valves.
I can see what I think must be two sets of valves on each boiler (I have 2) but can't see how I would...