There are two things I had on my system, and I think they might have made it a good one but I was using the earlier TMC heads and I did buy them from Whitworths.
I had such a good run without problems I recommended them to others based on my own experiences. I never had any rust on any
parts, but a fault all of these systems have is the sharp right angle bend at the base of the bowl.
Most times it works fine--but sometimes one has to add some detergent and allow stools to soak for an hour or so until they will soften and bend and go around that corner--otherwise one has to use a plastic wand to beat them into submission--but almost all of those low profile heads designs have the same problem, not just TMC...
Firstly, the blades need to be razor sharp. If they are not, then I would do this using a Dremel tool or something similar, while using some water in a squirt bottle to keep the
stainless steel and stone cool.
Secondly, one needs to run the macerator
pump from its own local pony battery--usually it is way too far from the house
battery room, so I used the heavy duty tractor
battery for the
anchor windlass. No problems with lack of
power.
That macerator draws about fifteen amps when running properly--so you need heavy
cables and good contacts.
Where the manual rocker switch is fitted, I wired this to not to the macerator pump but instead to operate a 30 amp waterproof
marine relay. I used heavy duty
cables to the macerator from the auxiliary
windlass battery relay so that the run of
wiring was only a metre or two, minimum
wiring of 6 mm tinned twin. If you can get 10 mm tinned twin use it. Sometimes you can get this sort of stuff at military disposals.
I had no problems with the system which received no other maintenance in five years of
live aboard use.