Firstly if its a issue with the boiler vessel I wouldnt look to repair it, repairs often fail after a year or cause fatigue and result in a failure else where in the vessel, due to the rapid heating and cooling associated with boiler.
My suggestion after reading the manual found here is:
Depending on the outcome of the above I think your most likly to find the fault is with a valve, elbow or gaugue which is leaking, which can be fixed by resoldering or an extra 1/4 turn of a compression nut.
While your not getting any faults or pressure loss, I would say that it is unlikly to be the boiler, or something which is uneconomical to repair.
As a workaround you could attach some cotton wool around the pipe to prevent any further water seeping down the pipe and damaging your floor again, but this is only a stop gap.
Looking at a manual they do have apointed service engineers who will attend for 'a fee' it may be worth contacting them to see what their fees would be, as they are more likly to want to repair the product than sell you a new boiler.
Hi, I just wanted to see if your happy to close the question, and if so if you could rate my response.If you need anything further would appreciate if you could reply back so I can assist further.