I have a DC39 Animal I forget how old (the last ones before the EU power regulations changed) it's had me scratching my head, it has poor suction audibly hear it sounds gutless, the head seems to only spin at reduced speed, but it seems to chew through pre-filters (genuine and pattern filters) if the pre filter is brushed off before doing a hoover it'll be sort of okay but then the next time it's picked up to be used the suction seems to be reduced again.
When it's powered on you can see the arm really suck down onto the pre-filter and when it does give full suction it's perfectly capable of lifting the carpet and spinning like normal.
I've checked for blockages, made sure the trigger head brush isn't wrapped in fluff, I've tried genuine pre-filters, pattern ones. I'm hesitant to buy new head, or cyclone and filters really aren't lasting. My only thought was perhaps the HEPA filter is really clogged up.
I've looked at others with similar symptoms but they never seem to solve the problem.
Any obvious thoughts or suggests gratefully received.