Baxi Solo 3 PF Boiler ventilation

We have recently moved into a house where the boiler is situated within a cupboard with a Venetian door. The boiler is a Baxi Solo 3 80 PF and according to the installation manual (conveniently left by the previous owners) the "appliance may be fitted inside a cupboard. Cooling ventilation and insulation of the cupboard is not required". Am I right in interpreting this to mean that the boiler doesn't need any source of ventilation in the cupboard as long as the minimum clearances aren't encroached upon?
The thing is, the boiler is quite loud and tends to wake the wife in the morning so I would like to somehow reduce the noise emanating from the cupboard. The obvious answer would be to simply put a piece of hardboard/MDF across the back of the slats but I had assumed the boiler would need some sort of air flow around it?
Is any one familiar with this boiler?
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