Mick,
 
Go down into the lower 2nd box and see if you can exchange some foundation
frames from the 3rd with drawn and filled honey frames from the 2nd.  If the
hive is doing well you should be able to pull at least the 2 outer frames on
both sides.  Don't go through the broodnest unless you need to (less
manipulation is best).  I'm assuming that the super is also a deep box.  The
bees don't work foundation above an excluder as freely as without one.  The
drawn frames will bring them up to work in the super more readily.  Remember
also that if all of the boxes are started as foundation that this is a bunch
of work to get done.  Be careful that they fill out the lower boxes with
drawn and filled comb.If they seem to be running up the middle frames only,
don't super anymore.  You might end up with partially drawn brood boxes late
in the season and will have to fill them out with frames from your super.
 It's better to force them to fill it out than you doing it for them.  They
know were to put everything the best.  Hope this helps.
 
Brian Tassey
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