Welcome to the Piper Boat Owners club Forum. The Forum for owners of Piper built Narrowboats and Barges and anyone interested in Piper Boats. The owners club is completely separate from Piper Boats. Please feel free to post a message to club members and web site readers.
Sounds daft I know but have you measured the depth of the inside of the cabinet and compared it to the depth of the outside, if there is no difference then clearly the pump aint there. If there is a difference then it might well be worth investigating further. On 'Fiddlers' the cupboard back is just a friction fit.
