Be Carefull! For the fuse to blow with a bang, it would suggest that there is a short circuit somewhere. It could be in the plug but is more likely to be in the internal wiring, motors or controller. Wherever water and electricity are used in conjunction, there is a risk of short circuit, fire and electric shock if not properly maintained and insulated.
If you paid a callout of £49, you should not have to pay a second callout for a second visit; you may have to pay for additional repairs though.
Tim.W, December 2008