Hi, I'm attempting a complete strip and clean of a very heavily lime-scaled volumetric La Scala Butterfly HX machine. The boiler, pipes etc. have all been descaled, I've just got the flowmeter left to clean.

Although it was capable of producing a consistent volume of water prior to being stripped down, there's evidence of scale around the inlet/outlet of the flowmeter, so I was after advice on the best way to clean it as the flowmeter appears sealed. Is it worth trying to pull apart (and if so, how?), or better to put the whole machine back together and running a couple of litres of citric solution through the machine? Essentially I just don't want to screw it up and have to buy a new one.

Many thanks,
Dave